Science 2 part 2

What you will doActivity 1.1 I Can See You! Spread out a sheet of newspaper on the floor. Cut ten 2 cm x 2 cm paper circles outof another newspaper, 10 paper circles out of black paper, and another 10 paper circles outof white paper. Scatter the 30 paper circles randomly across the sheet of newspaper on thefloor. Ask a partner to time you for 10 seconds, and pick up paper circles as many as youcan. Count and record the number of paper circles of each color you picked up. If thepaper circles represent organisms in an environment, infer which one would not likely befound by its predator? Which one is the fittest? What does it mean by evolution throughnatural selection? Key to answers on page 22. What you will do Self-Test 1.11. Natural selection allows certain species to survive. The organisms that survive are those best adapted to their environment. Does natural selection make organisms more complex and perfect?2. A giraffe’s long neck enables it to eat leaves of trees. How does this adaptation help the giraffe survive? Key to answers on page 22.Lesson 2. Evidences for Evolution Can the process of evolution be described theoretically or can it be actuallyobserved? Evidences to support the theory of evolution come from different areas ofscience. Let’s look at some of the evidences that support evolution. Evidences of evolutionare divided into two groups: direct and indirect. However, experts are arguing as to whatthe direct evidences and what indirect evidences are. This issue is yet to resolve.What does it mean by direct evidence? Direct evidence is something that can be directly observed or seen. Fossils are theremains or impression left by an animal or by plants preserved in the earth crust. Aconsiderable number of experts claim that fossils provide direct evidence for evolution (ifyou have access to internet, visit these web sites:http://library.thinkquest.org/22446/Evidences.html?qskip1=1,http://www.coreknowledge.org/CKproto2/resrcs/lessons/498HxEarth.htm, -8-

http://www.talkorigins.org/faqs/evolution-research.html, http://www.rwor.org/a/v24/1161-1170/evol5.htm,http://www.life.umd.edu/classroom/biol1106h/Lec9/Biol1106_L9.html,http://nitro.biosci.arizona.edu/courses/EEB182/Lecture02/lect2.html).How can fossils provide evidence of the past life?According to manyexperts, fossil provides directevidence for evolution because itcan tell what has happened. Inother words, it can prove thatchange in time has occurred.When certain fossils arearranged in the order of how oldthey are, we can make a directcomparison of their bodystructures. Through these fossils Trilobite fossil Dinosaur skullexperts can confirm that speciesare not fixed but can evolve into other species over time.What problems are encountered in interpreting fossil evidence? Experts are having difficulty interpreting fossil evidence because the fossil record isrelatively incomplete. Do you want to know why? The first reason is that only a small number of fossils are found. Many organisms dieand vanish without leaving a trace. The quality of preservation also varies. Some arepreserved so perfectly and some are not. Soft tissues are rarely preserved. Erosion andearthquakes have destroyed other fossils. Moreover, that remains of organisms arepreserved only in places where condition is favorable.What does it mean by indirect evidence? Indirect evidence is something that does not involve actual observation of evolutionbut for which we can infer that evolution has taken place. Many scientists consideredgenetics, comparative anatomy, embryology, and biogeography as indirect evidences forevolution.How do homologous, analogous and vestigial structures indicate that evolution hasor has not occurred? Comparing the anatomy and the development of organisms reveals a unity of planamong those that are closely related. The more body structures that two species have incommon, the more closely they are related. It supports the idea of “descent from a commonancestor”.Would you first like to know what homologous and analogous structures mean? -9-

Similar structures indifferent species irrespective oftheir functions are calledhomologous structures.Homology seems to indicatedescent from common ancestor.The limb skeletons of vertebratesare homologous structures. Figure2 illustrates homologous structuresamong vertebrates. Figure 2. The limb skeletons of vertebrates are homologous structures. http://www.geo.arizona.edu/Antevs/nats104/00lect12.html Analogous structures are structures,which are different in appearance but have thesame function. Analogy does not indicatecommon ancestry. Examples of analogousstructures are the legs of insects andmammals, and wings of butterflies and birds.Figure 3 illustrates analogous structuresamong vertebrates. Figure 3. Analogy of bat & bird wings http://www.mun.ca/biology/scarr/ Analogy_of_forelimbs.htm Vestigial structures seem to provide further evidence for evolutionary change.Vestigial structures are anatomical features that are usually reduced and have no function inmany organisms. These are organs that were once functional in the ancestors of thespecies but are only remnants in the present species. For example, skeletal limbs found insome snakes have no known use to these animals. In humans, appendix is thought to haveno use, but in other mammals it aids in the digestion of cellulose. What other vestigialstructures are thought to be found in humans? Some Asserted Vestigial Organs in Man Tonsils Adenoids Coccyx (tail bone) Nictitating membrane of eye Thymus Appendix Little toe Wisdom teeth Nipples on males Parathyroid Nodes on ears \"Darwin's points\" Ear muscles for wiggling Pineal gland Body hair “Note; Most of these organs are now found doing their function/s.” - 10 -

How can genetics and molecular biology support evolution? Living things shared several similar biochemical molecules, such as DNA, ATP,amino acids, and enzymes. This finding supports descent from a common ancestor. Themore closely related organisms are the more similar is their biochemical makeup.How can biogeography prove descent from common ancestor? Biogeography is the study of the distributions of organisms. Darwin’s trip aroundSouth America allowed him to observe the diversity of organisms in different areas and theresemblance of such species of birds and tortoises in an island to nearby mainland. Darwinbelieved that the group of animals in each island is adapted to a different way of life. Thecommon ancestors of these organisms had come from one locale, spreading out into otheraccessible areas.How can embryology tell whether evolution has or has not occurred? The unity of plan shared by vertebrates extends to their embryological development.The embryonic development of all vertebrates shows remarkable similarities. At some timeduring development, all vertebrates have a supporting dorsal rod, called a notochord, andexhibit paired pharyngeal pouches. This could indicate that an organism passes throughsome of the embryonic stages that its ancestors passed through. Then severalmodifications happen in ways appropriate to an organism’s final form. Look closely at theillustration below. What similarities do you observe among the eight vertebrates (fish,salamander, tortoise, chick, hog, calf, rabbit and human)? Figure 4. Vertebrate embryonic development http://zygote.swarthmore.edu/evo5.html - 11 -

In the next activity you will appreciate a body structure that is present in us and insome organisms related to humans. What you will do Activity 2.1 What a Thumb Can Do For You Do you know how important your thumbs are? Only primates have hands capable ofgrasping objects. The grasp is made possible by the opposable thumbs. Are you awarethat you perform a lot of tasks using your thumb and fingers? Have you experienced doinga series of tasks without the aid of your thumb? Ask a friend to tape your thumbs to the palms of each hand with masking tape. Becareful not to wrap the tape too tightly because it will cut off the blood circulation to yourhand. Then do the following: a. write your name with a piece of chalk on the blackboard b. pick up your pencil c. turn the doorknob d. pick up a drinking glass e. unbutton or rebutton a shirtQuestion: How has having an opposable thumb helped primates, especially humans to adapt totheir environment and survive better than other animals? Key to answers on page 22. What you will do Self-Test 2.11. Can you explain why some extinct plants and animals were not fossilized?2. A friend tells you, “man came from apes” because many structural and biochemical similarities are found between them. How would you react to this?3. What does it mean by direct evidence for evolution? Indirect evidence for evolution? Do you agree that fossils provide direct evidence for evolution? Why or why not? Key to answers on page 22. - 12 -

Lesson 3. Process of Evolution When Darwin wrote his book, On the Origin of Species, he knew nothing aboutgenetics. Today, population geneticists apply the principle of genetics to determineevolutionary relationships among species. From the geneticist point of view, evolution is defined as a change in gene pool. Do you know what gene pool is? Gene pool pertains to genetic composition ofindividuals in a population. Let’s say, in a population of puppies, the gene pool is 50 pure black puppies, 25spotted (black and white) puppies, and 25 pure white puppies. If all the males and females in the same population mate and reproduce, there is atendency for the gene pool to remain the same generation after generation. No change ingene pool or genetic composition will occur.So how can evolution or change in gene pool occur? In real life animals migrate and find other mates, genes continually mutate, andnature allows the fittest organisms to survive. When these conditions happen evolution hasoccurred. Let’s discuss the specific conditions for evolution to occur.A. Non-random mating By non-random mating, we mean that sexual selection is not merely by chance. Individual’s choice of mate is influenced by some physical and behavioral characteristics. For example, white rabbits preferentially mate with rabbits of their own color. In humans, tall women prefer tall men rather than short men. Inbreeding, which is commonly observed in plants and in some kinds of animals, is a very good example of non-random mating. Inbreeding in plants is sometimes called self- fertilization. Animals like dogs, rats, cats, rabbits, pigs, and many other animals practice inbreeding. Inbreeding can result to a population whose members are alike in appearance, fitness, and lifestyles.B. Mutation The organism’s appearance is dictated by the information stored in its chromosomes. So, if the chromosome’s structure or gene composition is changed, the appearance of the organism will also be changed. Any change in the structure of chromosomes and gene composition is called mutation. - 13 -

What causes mutation? There are several agents for mutation (mutagens) like ultra violet radiation and hazardous chemicals in the environment. These mutagens can change the information stored in individuals’ chromosomes or genes. Therefore, when mutation occurs, the appearance of individuals in the population changes, and the gene pool becomes different from the original population.C. Genetic drift Genetic drift means change in gene pool due to chance alone. Unpredictable disasters or accidents such as earthquakes, floods, fires and diseases can reduce or totally eliminate certain traits in the population. Let’s say flood wiped out a population of ants. No matter how good the ants are adapted to its environment, they could be killed by such event. In this situation, the survival or death of individuals in the population has nothing to do with their fitness. Genetic drift is also observed when a harmful insecticide has killed a big population of fruit fly, leaving a few members with particular trait. The next generation of fruit flies will inherit only the trait present in the survivors. The success of this trait is due to chance but not because it is the fittest trait. Genetic drift also happens when a small population breaks off from a larger population and forms a new population. The resulting population inherits the traits of the founders, so the new population becomes very different from the ancestral population.This mechanism is seen in all the cattle in Iceland. The ancestors of these cattle arebelieved to come from a small group that was brought to the island more than onethousand years ago. Studies revealed that the genetic make-up of the Icelandiccattle is now different from that of their cousins in Norway.Do you know some families or groups of people who isolated themselves from thesurrounding populations?One example is the Amish group ofPennsylvania. This isolated groupwas founded by a family thatcarries a very rare condition knownas Ellis-van Creveld Syndrome.The Amish with this syndrome hasan unusual dwarfism and- 14 - Figure 5. Amish child with Ellis van Creveld syndrome www.visual-evolution.com/polydactylism.htm www.mercydesmoines.org/ADAM/.../

polydactylism, or extra fingers. Today, this rare syndrome is common among theAmish group. Figure 5 shows an Amish child with Ellis-van Creveld Syndrome.D. Gene FlowGene flow occurs when individuals migratefrom one population to another. Gene flowincreases variations in the population. Aneffective sharing of traits happens when onemigrates and interbreeds with the individuals ofnewly found population. Often, this results toan increase in the intermediate phenotypes inthe population.Gene flow can also occur without migration. Figure 6When people travel to another area and Marriage between races ofteninterbreed with the existing population there,an effective exchange of genes occurs produces individuals ofbetween the reproducing individuals, even intermediate appearance.though the traveler returns home. Forexample, during the U.S and Vietnam War inearly 1970’s, many American soldiers hadchildren with Vietnamese women. Because ofthat, the gene pool of the Vietnamesepopulation has altered.Look around you. Have you noticed that plantsand animals are so diverse? There are red,white, pink, and yellow rose flowers? Thereare white, brown, and black dogs, some arebig, and some are small. Gene flow or geneticexchanges similar to these make a populationmore diverse.Human species is also diverse. Asians,Americans, Africans, Europeans are physicallydifferent. However, no matter how diverse thehuman population has become, humans stillremain as one species as long as themembers continue to interbreed successfullyand share a common gene pool.E. Natural SelectionSo how does natural selection affect the evolution of a population? - 15 -

Based on what you have discussed in Lesson 1, nature selects which trait will survive and which will not. These organisms with favorable traits, meaning those who are best suited in the environment, have a better chance of survival. The survivors pass on the favorable traits to their offspring, then after many generations, the population will produce organisms with traits that are very different from their ancestors.What is speciation? Speciation is simply the formation of new species. Oops! You should not confuseevolution with speciation! Evolution can lead to speciation. Speciation requires numerouschanges in the gene pool of a population, usually over a long, long period of time. Are you excited to know how new species occur? Before we reveal it, first you needto define the meaning of species. Very good! A species is a group of organisms that are able to interbreedsuccessfully, and produce fertile offspring who themselves can reproduce. Each species isreproductively isolated from every other species. Normally, gene exchange occurs only betweenthe populations of a species but not betweenpopulations of different species. In other words, members of a species cannotinterbreed with members of another species. Forexample, Felis tigris (tiger) is one of the cat species,but they cannot reproduce with Felis domestica(domesticated cat), which is another cat species.Man is a primate; it reproduces only with man but notwith other primates like apes and monkeys. But wait look at the picture below! Mating a horse and a donkey produces a mule??? Well, as what the picture tells you, horses anddonkeys can have offspring! Sometimes breeding may takeplace but if so, the offspring are not so fertile and welladapted as the parents. For your information, the muleproduced is sterile; they cannot have offspring! http://www.fs.fed.us/r2/psicc/spl/string.shtml http://www.archiveangel.com/gallery/white-horse-2.htm http://www.execulink.com/~wblank/donkey.htm - 16 -

What happens when gene flow does not occur between the populations? When there is no gene flow, the populations become reproductively isolated and overtime the populations will become separate species – a process known as speciation.What are the two types of speciation? There are two types of speciation: allopatric and sympatric. In allopatric speciation, a population is split into two by a geographic barrier. Thebarrier may be a mountain, river, ocean, valley, desert, or anything that physically preventsthe mating between individuals of two populations of the same species. The two sub-populations experienced the mechanisms we have mentionedpreviously (natural selection, mutation, or genetic drift). Gradual changes accumulate toeach of the sub-populations until they become very different from each other. If they do come to occupy the same territory again and successful mating occurs,speciation has not occurred. But if they fail to reunite and produce offspring, speciation hasoccurred and they have become separate species. In sympatric speciation, two or more species arise from a single ancestral species inthe absence of physical barriers. Some pre-mating and post-mating barriers such as foodpreference, mating behavior or sterility, prevent effective gene exchange between thereproducing individuals. And when reproductive isolation has been established, speciationwill have occurred. Do this activity to find out how evolution by natural selection works. What you will do Activity 3.1 Beak VariationMaterials needed: “Food” stuff (beans, stones, marble, and anything else in that size range) A large basin Bird’s beaks (chopsticks, large forceps, clothes slip, shovel)Procedure: 1. You will play different types of birds with different types of beak shapes and sizes. 2. As a bird, you need to get more food to sustain your large body. 3. One at a time use different types of beaks (chopsticks, forceps, shovel and clothes clip) to feed on whatever you can grab with your beak. Do this for two minutes for each type of beak. - 17 -

Questions: 1. With which beak type were you able to grab more food? 2. Which beak type is the fittest? 3. How can nature choose which variations appear in the next generation and which do not? Key to answers on page 23. What you will do Activity 3.2 Agents of Evolutionary Change Label each statement with the correct agent of evolutionary change. Write your answer on a separate sheet of paper.Choices: gene flow, genetic drift, mutations, natural selection, and non-random mating.________ 1. A female peacock chooses mates with the most colorful feathers.________ 2. Giraffes with longer neck get a larger share of resources and tend to have more offspring.________ 3. Bacteria and insects become resistant to agents that formerly kill them.________ 4. The Inca Indian population was founded by a small number of individuals, all of which had type O blood.________ 5. During American and Vietnamese War, many U.S soldiers had children with Vietnamese women. Key to answers on page 23. What you will do Self-Test 3.1 1. Why is reproductive isolation needed for a new species to form? 2. Differentiate allopatric speciation and sympatric speciation. 3. Can the process of evolution be described theoretically or can it be actually observed? Key to answers on page 23. - 18 -

Let’s Summarize What are the things that you have learned from this module? 1. Creationism is the idea that living things are created and remains unchanged since the beginning. 2. Catastrophism is the idea that violent and sudden natural catastrophes have resulted to death and extinction of most plants and animals. After each catastrophe, God created new sets of life forms. 3. Uniformitarianism claims that large geological changes occurred not in catastrophic events but by gradual accumulation of small geological changes over long periods of time. 4. Jean Baptiste de Lamarck believed that the environment could bring about inherited change. 5. Darwin proposed the theory of evolution through natural selection. He believed that all organisms come from a common ancestor. 6. Evidences for evolution come from many sources. Evidences are classified as direct and indirect. Direct evidence means something that can be directly observed or seen. Fossils provide direct evidence for evolution. Indirect evidence is something that does not involve actual observation of evolution but for which we can infer that evolution has taken place. Genetics, comparative anatomy, embryology, and biogeography offer indirect evidences. 7. Similar structures in different species irrespective of their functions are called homologous structures. Analogous structures are those that generally perform the same function though possibly in very different ways. Vestigial structures are anatomical features present in organism but have no function. 8. Natural selection is not the only driving force for evolution to occur, other mechanisms include non-random mating, gene flow, genetic drift, and mutations. 9. Two types of speciation are identified: allopatric and sympatric. Allopatric speciation happens when a population is split into two by a geographic barrier. In sympatric speciation, a population is split into two or more in the absence of physical barriers. PosttestAfter going through the module, I am sure you can now perfectly answer the followingquestions.Multiple Choice. Choose the letter of the correct answer. Write the chosen letter on aseparate sheet of paper.1. Which idea stems from the theory of evolution? - 19 -

a. The earth is relatively young.b. Each organism is specially created.c. Species are related by common descent.d. A mix of fossils in a region indicates that a local catastrophe occurred.2. An adaptation promotes c. the chance to survive and reproduce a. the chance to reproduce d. none of the above b. the chance to survive3. Vertebrate forelimbs are most likely to be studied ina. biogeography c. ecologyb. comparative anatomy d. embryology4. Which is NOT true of fossils? a. They indicate that life has a history. b. They are evidences of life in the past. c. The older the fossil, the less it resembles modern day species. d. They look exactly like modern-day species, regardless of their age.5. During the usual process of speciation, a species is first isolateda. behaviorally c. geographicallyb. genetically d. reproductively6. Which type of speciation requires a geographical barrier?a. allopatric c. divergenceb. convergence d. sympatric7. The criterion used to distinguish between two species is based ona. geography c. reproductionb. physical traits d. time8. Which of the following statements does NOT describe Darwin’s theory of natural selection? a. Members of a population will compete. b. Populations tend to reproduce in small numbers. c. Members of a population have heritable variations. d. Some members of a population have adaptive traits.9. Which of the following describes indirect evidences for evolution? a. consists of actual observation b. is actually observed or seen c. is something that does not involve actual observation of evolution but for which we can infer that evolution has taken place d. None of the above.10. Which of the following mechanisms will cause the gene pool of two populations to become similar? - 20 -

a. gene flow c. mutationb. genetic drift d. natural selection11. Which of the following describes mutation? a. A result of inbreeding. b. Any change in the structure of chromosomes. c. Change in gene pool due to unpredictable situation. d. Differential survival and reproduction of organisms.12. What agent of evolutionary change can result to a population whose members are alikein appearance, fitness and lifestyles?a. inbreeding c. genetic driftb. gene flow d. mutation13. What is genetic drift? a. a change in gene pool due to chance alone. b. A mechanism that increases variations in the population. c. The differential survival and reproduction of organisms. d. A change in the structure of chromosomes and gene composition.14. Which type of speciation does not require a geographical barrier?a. allopatric c. divergenceb. convergence d. sympatric15. What does it mean by direct evidence for evolution? a. consists of observations of actual evolution b. does not involve direct observation of evolution c. is something that is not actually observed or seen d. None of the above. Key to answers on page 24.Key to AnswersPretest 6. a 11. b 7. c 12. a I. 8. b 13. a 1. a 9. c 14. d 2. c 10.a 15. a 3. d 4. d 5. c - 21 -

Lesson 1Activity 1.1 Organisms that blend well with their environment would not likely be found by theirpredators, so they have greater chance to survive and leave more offspring than others whocan not blend as well; they are the fittest organisms in the environment. Natural selectionaccording to Darwin is one mechanism for evolution. Because some survive better thanothers, natural selection tends to eliminate less fit characteristics. Over many generations,differential survival and reproduction generate new adaptations and new species.Self-Test 1.1 1. Natural selection does not make an organism more complex and perfect. In some environments it is better to be less complex, and in such environments complex organisms may be eliminated by natural selection. Natural selection does not result in species that are perfectly adapted to its environment. As environment changes, species may be likely to be adapted to a previous environment, rather than the present one. 2. Giraffes with long neck have advantage in obtaining more food over giraffes with short neck. They can reach tall trees for food, thus they have greater chance to survive and reproduce more than the short-necked giraffes.Lesson 2Activity 2.1 The opposable thumbs enable primates to perform a lot of tasks efficiently. The opposable thumbs allow both precision manipulation and a power grip.Self-Test 2.1 1. Not all organisms leave a proper fossil. They may die and vanish without leaving a trace. Other fossils are not preserved well. Some fossils are destroyed by earth’s movement before they are dug up and studied. 2. It is true that many structural and biochemical similarities are found between man and apes. But it is wrong to say that man came from apes. Based on fossil, embryological and DNA analyses, we are close relatives of apes. These evidences for evolution suggest that man and apes shared a common ancestor. Apes did not transform to become man. If they did, you will hardly see a population of apes today. Do not confuse evolution of species with transformation of species. - 22 -

3. Direct evidence for evolution consists of observations of evolution. Indirect evidence does not involve actual observation of evolution but for which you can infer that evolution has taken place. Answers of students, as to whether fossils are direct or indirect evidences for evolution, may vary.Lesson 3Activity 3.1 1. The shovel (as beak type) allowed the bird to grab more food than other beak type. 2. The fittest bird has beak type that allowed it to get more food than other birds with different beak type. More food resources mean better survival and reproduction. 3. The organisms with favorable traits are allowed to adapt to a changing environment. Their traits have the greater chance to become prolific in the next generation. Those who are unable to adapt are reduced or eliminated in the population.Activity 3.2 1. Non-random mating 2. Natural selection 3. Mutation 4. Genetic drift 5. Gene flowSelf-Test 3.1 1. Reproductive isolation can prevent gene flow; it can split interbreeding populations into genetically distinct species. 2. Allopatric speciation happens when a population is split into two by a geographic barrier. These barriers physically prevent the mating between individuals of two populations of the same species. Gradual changes accumulate to each of the sub-populations. If they do come to the same territory but fail to reunite and produce offspring, speciation has occurred and they have become separate species. In sympatric speciation, a population is split into two or more in the absence of physical barriers. Some pre-mating and post-mating barriers such as food preference, mating behavior or sterility, prevent effective gene exchange between the reproducing individuals. And when reproductive isolation has been established, speciation will have occurred. 3. Based on the evidences it presents (fossils, comparative anatomy, embryology, biochemistry and biogeography) and the mechanisms that work in nature, evolution seems to be actually observed. - 23 -

Posttest 6. a 11. b 7. c 12. a I. 8. b 13. a 1. a 9. c 14. d 2. c 10.a 15. a 3. d 4. d 5. cReferencesBooks:Mader, S. (2001). Biology. (7th Ed.) USA: Mc Graw Hill Publishing Company.Hopson, J. & Wessel, N. (1990). Essential of biology. USA: Mc Graw Hill Publishing Company.Unpublished thesis:Malonzo, E. R. (2003). Developing conceptual understanding on evolution through social constructivist approach. Unpublished masteral thesis, Philippine Normal University, Manila.Electronic sources:Retrieved on February 2, 2005 from http://www.sirinet.net/-jgjohnso/tree.htmlRetrieved on February 3, 2005 from http://www.biology.arizona.edu/evolution/act/drift/ about.htmlRetrieved on February 3, 2005 from http://www.lander.edu/rsfox/evollll.htmlRetrieved on February 7, 2005 from http://www.library.thinkquest.org/22446/ Evidences.html?tqskipRetrieved on January 17, 2005 from http://www.strangescience.net.darwin.htmCharles - 24 -

Module 16 The Diversity of Plants What this module is about This module will take you to the wonderful world of plants. It aims to familiarize youwith the different groups that comprise the Plant Kingdom and with how plants areclassified. Plants make up one of the dominant organisms on earth. Since plants are foundalmost everywhere in a tropical country like the Philippines, we are familiar with many of itsspecies. This module has five (5) lessons:  Lesson 1 – Classification of Plants  Lesson 2 – Non-vascular Plants (Bryophytes)  Lesson 3 – Vascular Plants (Ferns and Fern Relatives)  Lesson 4 – Vascular Plants (Cone-Bearing Plants)  Lesson 5 – Vascular Plants (Flowering Plants) What you are expected to learn After going through this module, you are expected to: 1. Discuss the importance of classifying plants. 2. Describe how plants are classified. 3. Compare non-vascular from vascular plants. 4. Explain how the different groups of plants differ from each other. 5. Describe some representative plants from the different groups. How to learn from this module In order to achieve the objectives of this module, you are expected to:

1. Read and follow the instructions carefully.2. Answer the pretest first.3. Take down notes and record points for clarification.4. Follow the instructions in the activity, so you can perform them very well.5. If specimens are necessary, try to look for them.6. Take the posttest and check your answers with the key to correction at the end of the module.What to do before (Pretest)Multiple Choice. Choose the letter of the correct answer. Write the chosen letter on aseparate sheet of paper.1. What do you call the process of grouping or ordering plants based on structuralsimilarities or evolutionary relationships?a. classification c. identificationb. collection d. preservation2. There are seven major biological levels of classification. The species level is thesmallest unit. What is considered as the largest unit of classification?a. class c. kingdomb. family d. order3. Who was the first Swedish naturalist to classify living things? This man is regarded asthe father of Taxonomy.a. Anton Van Leuwenhoke c. Charles Darwinb. Carolous Linnaeus d. Robert Hooke4. What do you call the type of classification that is based on similarity of structures?a. natural classification c. superficial classificationb. artificial classification d. phylogenetic classification5. Vascular plants produce the tallest and biggest trees in the world. Non-vascular plantsare small and cannot grow as tall as vascular plants. What could be the reason for this?a. absence of water c. lack of vitaminsb. absence of leaves d. absence of vascular bundles6. Plants are classified for the following reasons:a. to avoid confusion c. to create chaosb. to store things d. to find things fast -2-

7. What is the type of vascular arrangement in monocot plants?a. alternate c. ovalb. circular d. scattered8. Plants maybe classified as vascular and non-vascular. Which of the following arevascular bundles?a. endodermis and pericycle c. sclereids and scherenchymab. parenchyma and collenchyma d. xylem and phloem9. Strobili are reproductive structures found in:a. fern c. pine treesb. cactus d. club mosses10. Plants are found in almost all types of habitat. Which among the following habitats isNOT favorable for the growth of mosses?a. damp soil c. dry, unshaded placesb. moist rocks d. trunks and branches of shaded trees11. How many cotyledons does a dicot plant have?a. one cotyledon c. four cotyledonsb. two cotyledons d. three cotyledons12. Vascular bundles help in the transport of substances in plants. What vascular bundletransports water and minerals upward in plants?a. collenchyma c. phloemb. parenchyma d. xylem13. Which of the following plants has a parallel type of leaf venation?a. coconut c. peanutb. gumamela d. pilinut14. Which of the following plant is NOT a gymnosperm?a. ginkgo c. olivab. gumamela d. podocarpus15. Which plant exhibits the taproot type of root system?a. bamboo c. orchidb. carrot d. palay Key to answers on page 28. -3-

Lesson 1. Classification of Plants Have you ever experienced walking in a park, or a garden where different plants arefound? Or have you walked down the yellow trail in Camp John Hay? The trail sides hasmany grasses, ferns, and trees, which are all members of the plant kingdom. What do allthese plants have in common? How are they grouped? What are their differences?Similarities? Find out as we discuss the topic on the classification or grouping of plants. Now, examine the figure on theright. It is the evolutionary tree ofplants. Try to note the similarities anddifferences of these plants. These arethe plants that you will study in thismodule. The diagram shows theevolutionary relationship of thedifferent groups of plants. All theseplants will be discussed in the lessonsincluded in this module. Figure 1Evolutionary tree of land plants Merrill Life Science (1994)What you will doActivity 1.1 Classifying SeedsTry this simple activity: Get 8 different kinds of seeds such as garbanzos, achuete, mongo, white bean, blackbean, corn, chico, and papaya seeds. Divide the seeds into two groups I and II. The seedsin each group must have at least one thing in common. For example, seeds that are roundmust be under Group I and seeds that are not round in Group II. Now, examine the seedsin Group I as to texture. Group them into rough and smooth. Rough seeds should beunder Group Ia and smooth seeds under Group Ib. Now move on to Group II and do thesame. Divide the seeds as to texture. Rough seeds will be Group IIa and smooth seedsunder Group IIb. Once you are through with the texture, divide or separate each seed inthe subgroup as to color. Let's say, black, yellow, green, red or white. -4-

Was it easy? Well, if you have doubts, you can use this diagram below as yourguide: Different Seeds Garbanzos, papaya, corn, mungo, achuete, back beans, white beans, chicoSHAPE GROUP 1 GROUP IITEXTURE ROUND NOT ROUND ROUGH SMOOTH ROUGH SMOOTHCOLOR YELLOW BLACK GREEN BLACK YELLOW RED WHITE BLACK (garbanzos) (papaya) (mongo) (beans) (corn) (achuete) (beans) (chico) Now, answer these questions: 1. What are your bases for classifying the seeds? 2. Based on your classification, how many different seeds do you have? 3. What is the advantage of classifying the seeds?Why Classify? In science, the grouping or ordering of living things is called classification. Thisconcept of grouping things can be useful in your life, in your studies and in your home. Forexample, you use a classification system to organize your books on a shelf and your clothesin a cabinet. Even in business and industry, classification systems are used. Classificationis actually a lifetime skill that you will practice every day in your life. Try This: Go to a grocery store or a supermarket nearby. See for yourself how the goods are grouped. Most grocery stores group similar items together. Examples of these are the dairy products, meat, canned goods and laundry items. Do they follow a systematic way of arranging the goods? How could you apply this to your everyday life? The system of classification we use today was developed by a Swedish. -5-

It was Carolous Linnaeus, an English naturalist, who pioneered the science ofclassification or Taxonomy. His classification was mainly based on similarity of structure.A structure is a feature just like the type of leaf, type of venation, type of fruit, etc. Presently,we have approximately 550,000 different species of plants that have been described andmany more are still being discovered. You can just imagine what will happen if no system ofclassification was followed. There will be a total confusion and disorder in the living world.Always remember this: Classification helps you to: 1. Organize things 2. Store things 3. Find things fast Applying concepts In what way is classification useful in libraries? In your home? In a sari-sari store? In supermarkets?If you answered - in libraries, it facilitates an easy way of finding books and references, athome, saves time to locate things, and sari-sari / groceries for convenience and fast action,you are right!Levels of Classification There are seven major biological groupings or levels of classification that we follow.The kingdom is the largest group in the system of classification. This is divided into phylain the animal kingdom. However, in plants this is equivalent to the division. Each divisionis divided into classes; these classes are divided into orders and orders into families, thenfamily into genera and so on down to the smallest unit, which is the species. The speciesis the basic unit of classification. As you move from kingdom down to the species level,classification becomes more specific. Originally, C. Linnaeus set up a two–kingdom system. The Plant and Animalkingdoms. After his time, many more biologists reclassified living things into more than twokingdoms. Now we are following a 6-kingdom system and actually there are already morethan 8 kingdoms discussed in some books. The six kingdoms are as follows: KingdomAnimalia, Plantae, Protista, Fungi, Achaebacteria and Eubacteria. Animals are themulti-cellular, heterotrophic (using other living organisms for food) organisms without cellwalls in their cells. Plants on the other hand are the multi-cellular, photosynthetic organismswith cell walls in their cell membranes. Protists are organisms that exhibit both plant andanimal characteristics. The eubacteria and the archaebacteria composed of cells withouta true nucleus and mitochondria. Fungi are plant-like organisms without chloroplasts. -6-

Challenger Question Suppose you discovered a new multi-cellular organism.This organism has a nucleus, mitochondrion, and a bigchloroplast in its cells. In what kingdom, would you place thisorganism? Why?If you answered – plant kingdom, because all the characteristics mentioned are exhibited byplants, you are correct! An easy way to understand the descending nature (largest to smallest) of scientificgrouping is to compare it with the general to specific information on where a person lives.For example:Country: Philippines Kingdom: PlantaeRegion: IV Division: MagnoliophytaProvince: Palawan Class: LiliopsidaCity: Puerto Princesa Order: LilialesBarangay: Sta. Lucia Family: LiliaceaeStreet: Chico Genus: AlliumHouse #: 45 Species: cepa If you examine the analogy of classification to where a person lives, you will find outthat as you move from kingdom to species, things become more specific. It is just likelocating the place where a person lives. In the given example, you start with the name ofthe country, the region where the person resides and the specific province in the region; thetown or city in the province; and so on until you finally get the street and house number ofthe person. In science, the same principle is followed to make things easier, because weare grouping not only hundreds or thousands of living organisms but millions of them! There are two systems of classification, the artificial and the natural system. Theartificial system of classification used in plants is based on size, water requirement, abilityto manufacture food, habitat, habit and life span. In other words, classification under thissystem is based on similarities. The natural system of classification is based on thestructural and evolutionary relationships among the organisms.The following gives more details on the bases of artificial system of classifying plants:1. Size – plants may be microscopic or macroscopic. Microscopic plants are those that are not visible to the naked eyes, while macroscopic plants are those that can be seen with the naked eyes. The plants that you see around you are mostly macroscopic.2. Water requirement a. xerophytes – live in places with little amount of water as in deserts. Examples of these are cacti, acacia and makahiya. -7-

b. mesophytes – require a moderate amount of water supply as those found in your garden. Examples are santan, rose, and sampaguita c. hydrophytes – those that live in habitats of abundant water supply. Examples: quiapo, water hyacinth, and digman.3. Ability to manufacture food a. autotrophic – those that manufacture their own food through photosynthesis. Examples: all green plants. b. heterotrophic – those that depend on other organisms or dead organic matter for food. Examples: all the carnivorous plants.4. Habitat – environmental location of the plants. a. aquatic plants – those that live in water. Examples: lotus, water hyacinth and water lily. b. terrestrial – those that live on land. Most of the plants we have in our garden are terrestrial in habitat. c. aerial – those that live above the ground on other plants or are attached to other objects for support. Examples are the orchids, bird’s nest and pocket ferns.5. Life span (duration of life) a. annuals – live for one growing season or within the year (e.g onions, garlic, patola) b. biennials – those that complete their life cycles in two years (e.g. carrots, papaya, potato) c. perennials – those that live for many years. Most of the trees that we see around are perennial.6. Habit – refers to body appearance. a. trees – tall, woody, perennial plants with a single stem or trunk (e.g narra, mahogany, santol). b. shrubs – short, woody, perennial plants with several main stems arising at or near the ground (e.g. gumamela, santan, rose). c. herbs – with soft stems (e.g. oregano, sabila, mayana). d. vines – climbing plants (e.g. are squash, patola, beans.) Now, try to apply what you learned from this lesson on classification by doing theactivity below. You need to go to a place where many plants are found. What you will do Activity 1.2 Look for a garden nearby and get 8 samples of plants from a body of water, dampsoil, garden soil, and moist rock. Notice what the plant body is composed of. Are all the -8-

Microscopicplants composed of the same parts? Do they all have leaves, stems, and roots? Did you Macroscopicfind all of them in one place? Are they all of the same size? Do they all have flowers? Into Xerophytehow many groups could you classify them? Mesophyte HydrophyteFill-out the table below with the different kinds of plants that you have collected. AutotrophClassify the plants by checking the category to which they belong. Review pages 7-8 before Heterotrophyou start filling out the table. Terrestrial AquaticName of Plant Aerial TreeAnswer the following on the basis of your observations: Shrub1. According to habitat, what kind of plant is the most common? Herb Annual______________________________________________________________________ Biennial2. What kind of plant is not found in your garden? Perennial ______________________________________________________________________3. How many plants did you observe climbing the trees or other objects? Name them. ______________________________________________________________________ Key to answers on page 28. An example of a natural system of classification is the classification of plants intovascular and non-vascular. Non-vascular are those plants without the vascular tissues ortissues where water, minerals, and food pass through such as the xylem and the phloem.The next two lessons of this module will be about the grouping and ordering of plants basedon morphological and anatomical characteristics. -9-

What you will do Self-Test 1.1Direction: Identify what is being described.______1. The highest level of classification______2. Plants with vascular bundles______3. Plants that need only a small amount of water______4. The basic unit of classification______5. Plants with soft and green bodies Key to answers on page 28.Lesson 2. The Non-Vascular Plants (Bryophytes) Have you ever slipped on what you thought was smooth, solid ground? You got up,started to walk only to slip again? You looked around and saw that the ground was coveredwith something like green carpet. Do you know what that was? Well, they are called“bryophytes” or “lumot” in Tagalog. This collective term is composed of mosses,hornworts and liverworts. They differ as to structure. You see them in many places,especially in wet and moist places. Do you know what else is special about these plants? They do not have true roots,stems and leaves. Isn’t that interesting? All along, you probably thought that all plantshave roots, stems and leaves. But not these plants! And you know one more thing? Theseplants don’t grow from seeds unlike other plants that you know. They grow from spores,which are tiny seed-like bodies from which new mosses can grow. Spores are equivalent toseeds in the higher forms of plants. Try to perform this simple activity. You can do this even in your backyard ifbryophytes are available. What you will do Activity 2.1 Walk around the neighborhood or in your backyard and look for moist or dampplaces. Observe tiny green plants attached to the soil or to the rocks and stones.Individually they are not readily seen. They grow in masses and look like mats on the soil. - 10 -

With the scalpel, scrape the tiny plants together with a portion of the surface, onwhich they are growing. Place them in plastic bags and upon reaching home lay themseparately on the newspaper. Now, examine the plants closely, if possible with a handlens,and make a simple diagram of the plants on a bond paper. You can compare these with thediagram found in Figure 2. Are they similar to what you have?Mosses Liverwort Hornwortwww.scenicviewsstudio. www.mybitoftheplanet. www.ucmp.berkeley.edu/ com/natur... com/wildli... plants/an... Figure 2. Bryophytes The bryophytes, as they are commonly called, are composed of the mosses,liverworts and hornworts. They are considered as the first land plants. They do not havethe vascular tissues or tubes that will facilitate transport of substances. This is the reasonwhy they are called non-vascular plants.Have you heard? … that the bryophytes are called the “amphibians” ofthe plant world? They are similar to the frogs and toads of theanimal world in the sense that they can survive in water, too.Amphibian or amphibious refers to any organism that can liveon land and in water. Just like the frogs and toads, bryophytesneed water to complete their life cycle.Liverworts The term liverwort can be divided into two words - liver, which means that the plant is“liver-shaped” and wort, which simply means plant or herb. In the past, it was believed thatthis plant was useful in treating ailments of the liver. However, no proof was found that itwas effective. Until now this plant is still universally called liverwort. Examine closely the diagram on the next page. Notice the flattened, leaf-like plantbodies attached to the ground by “rhizoids” instead of a root. The tips of the leaf-likestructure are lobed or shaped like the liver, thus the common name liverwort. A closerexamination also reveals that there are two types of gametophyte plants, the male andfemale. Gametophytes are haploid plants that will produce the sex cells. The male containsthe antheridium, the male reproductive organ, while the female contains thearchaegonium, the female reproductive organ. - 11 -

Male Liverworts Female Liverworts www.mybitoftheplanet.com/wildli... Figure 3. LiverwortsHornworts These plants received their common names www.ucmp.berkeley.edu/from the resemblance of the sporophyte or the“spore-bearing” plant, to small cattle’s horns. They Figure 4l . tH/ornwortsseldom exceed 2 centimeters in diameter and areusually found in moist soil and shaded areas or maybe attached to trees. The hornworts are the smallestin size and in number compared to the liverworts andmosses. There are only about one hundred speciesof hornworts distributed around the world. Examine the diagram on the right. Each iscalled anthoceros, a representative of the hornworts.Do they look like cattle’s horn? Can you make predictions? A friend of yours lives close to the Sahara desert in Africa. She wants to grow a garden of bryophytes. Is this a good idea? What will probably happen to her garden?Compare your answer with this: I will advise her that it would be useless since bryophyteswill not grow in dry and hot places.Mosses Just like the other bryophytes, mosses have also two kinds of plants. Thesporophyte and the gametophyte plants. The gametophyte plant produces thereproductive cells or the egg and the sperm cell. Try to locate each plant using the diagramof the life cycle of a moss below. The gametophyte looks like any other leafy plants that wehave. They differ from more complex plants because of the absence of mesophyll tissue, - 12 -

stomata and veins. Notice that the sporophyte is attached to the gametophyte and isdifferent. It has a stalk and capsule. The capsule is visible from the outside with numerous“spores” or reproductive bodies inside the capsule. Refer to the diagram below for thedetailed parts of the plant.http://courses.washington.edu/biol101/david/specimen_quest.html Figure 5. Life Cycle of a MossWhat you will doSelf-Test 2.1Matching type. Match column A with column B. Write the letters only. A B1. Sporophyte with horn-like structures a. spores2. Where the sperm cells are found b. moss3. With a sporophyte found growing on the c. archegonia d. hornwort gametophyte e. antheridia4. The specific structure that houses the egg cell5. The reproductive bodies inside the capsule Key to answers on page 28.- 13 -

Lesson 3. Vascular Land Plants (Ferns and their Relatives) This is the second lesson of the module on Plant Diversity. You may work on thislesson only if you are through with the module on Non-Vascular Plants. You will beintroduced to the ferns and their relatives. Like the bryophytes that we have discussed inthe last lesson, ferns are also land plants. Theyare the first vascular land plants, meaning, thefirst group of land plants with conducting tubesthrough which water and food substances pass.They do not produce seeds, but instead, theyproduce spores for reproduction. Members ofthis plant group are described and discussedwith diagrams to reinforce the concepts. Look at the diagram on the right and study www.home.aone.net.au/.../bpenmar.htmlvery well the members of this plant group. Areyou familiar with them? They are very common Figure 6. Ferns and Fern Alliesalong the roadsides and flower shops. They aremostly ornamental plants.Do you know? …that more than 300 million years ago, during theCarboniferous Age a great number of ferns lived? This age isreferred to as the Age of Ferns. The carboniferous forestcontained many more species of club mosses, spike mosses,horsetails and ferns than are alive today. What you will do Activity 3.1 Examine the diagram of a fern and fern allies on Figure 6. Are they familiar to you?Do you observe them while walking along the roadsides in open and shaded areas? Try torecall the plants that you have seen and get samples of these plants. Compare them withthe illustrated ones. By comparing them, you will be able to identify the kind of fern that youhave. Since fern allies are not common, your collection might all be true ferns. They can bedistinguished by their showy leaves, with tiny brown spots on the undersurface, the sori(sing. sorus) See figure 11b. - 14 -

Answer the following:1. How many kinds of ferns did you collect? _____________________________________2. Are they all common ferns? ________________________________________________3. In what part of your garden did you collect your specimens? ______________________4. Do they have mature leaves? ______________________________________________ Key to answers on page 29.A Survey of Fern Allies In this group of plants, we will concentrate more on the ferns. The ferns are morecommon compared to the other groups. We will just make a simple survey of all its relativesusing diagrams or illustrations with short description. So let’s now start our survey of thefern relatives before we move on to the ferns.Whisk Ferns Look at the figure on the right. Is thisplant familiar to you? Well, this is the whisk fern.The members of this group are small with “fork–like” branches that look like a broom. They areconsidered the simplest of all living vascular landplants. There are only two surviving genera inthis group of plants, the Psilotum andTmesipteris. The illustration of these plants arefound below.Club Mosses Figure 7. Psilotum and Tmesipteris www.herbs2000.com/herbs/herbs_club_moss. The second group of fern relatives in theillustration are the club mosses. There arearound 1,000 species of club mosses. Theymaybe familiar to you especially if you live in theprovince. They are just along the roadsides.They just grow wildly and plentifully along theroadsides especially during rainy season.However, in summer, they wilt only to germinateagain during the rainy season. Club mosses areso called because their tips are club-shaped. Figure 8. Club Moss They are usually used in decorating www.herbs2000.com/herbs/herbs_club_moss.chapels in the provinces especially in some partsof the Bicol region during holy week. - 15 -

Horsetails There used to be 15 species of horsetail plants but now there is only one existing genus. The genus is Equisetum. All the other members of this group are already extinct. The plants are commonly called horsetail or “scouring rush”. Look at the illustration. It resembles a horsetail and this was how the plant got its name. Its stems are rough with silica crystals, no wonder then that in the past, people used this in scrubbing pots and dirty kettles. Take a closerFigure 9. Horsetail look at the picture. Have you seen one?www.herbs2000.com/herbs/herbs_club_moss. Perhaps you haven't because they are not a common ornamental plant.Fernswww.pocketflora.com/.../ www.pocketflora.com/.../ http://cache.corbis.com/agen ferns.htm ferns.htm t/12/37/76/12377696.jpg Figure 10 Figure 11aA tree fern (Cyathea) Fern with fiddlehead Figure 11b Fern with sori This is the largest and the first group of seedless vascular plants. There are around12,000 living species. It is believed that like the other vascular plants, many more specieshave been identified from fossils. During the Carboniferous period of the Paleozoic era,most ferns grew much larger than the fern species living at present. Species of fern treesfound today in tropical areas may reach 3-5 meters in height but ancient tree ferns grew ashigh as 25 meters. The difference in plant size before and at present could be attributed tothe change in the climatic condition. The genus of the common tree fern that exists today isCyathea. Ferns have true vascular tissues and strong roots. They may be creeping orunderground called rhizomes. The large leaves are called fronds. When fronds mature,sori are formed on its underside. Inside these are sporangia where spores are formed. - 16 -

They undergo alternation of generation just as any other member of this group. The leafyfern is the sporophyte. When leaf ferns are young, they are coiled and are called“fiddleheads” or croziers. You can see this in figure 11. After a few days, little by littlethey uncoil into leafy fronds. Observe this yourself. This might take you a week to monitor.Examine the fiddlehead in the given illustration. Observe this: Look for ferns growing in your garden and take note of the appearance of “fiddleheads” or croziers. These are young, coiled fronds of the ferns. Consider this as day 1. Record the height, and appearance of the crozier. The next day do this again until after the whole leaf or frond is fully opened and uncoiled. This time describe how the leaf or frond look like. What you will do Self-Test 3.1Direction: Answer the following questions briefly.1. Which among the fern relatives looks like a tail of the horse? _____________________2. Which among the fern relatives is comparable to the broom in shape? ______________3. In what part of the fern is the sori usually found? _______________________________4. Why do ferns reproduce very fast? __________________________________________5. What are the economic values of ferns? ______________________________________ Key to answers on page 29. - 17 -

Lesson 4. Vascular Plants (Cone - Bearing Plants) What trees do you usually associate with the Christmas season? Is it narra, acacia,mahogany or pine tree? I’m sure your choice is pine tree. Really, pine trees are verypopular during the Christmas season. Almost everybody wants a decorated Christmas treein the house. What makes a pine tree ideal for the season? Well, most probably it is theshape of the tree, the needle–shaped leaves and of course the cones. The cones are highlydecorative. They can be varnished and converted into beautiful Christmas decors. Thislesson is focused on conifers or the cone-bearing plants. Pine trees are only one of theexamples under this group of plants.What you will doActivity 4.1 Use diagrams in this lesson to be familiar with the plants mentioned, or if possible, tryto check if these plants are found in your place. Cone-bearing plants include Cycads,Podocarpus, Pinus, (or pine tree) and many more. Compare these three common plants.Be guided by the following characteristics:a. height of the plantsb. habitc. leaf characteristics Key to answers on page 29. Cone–bearing plants are grouped under Division Gymnospermae. The name came from the Greek word \"gymnos\" meaning naked and \"sperma”seed, thus naked seed. Cone-bearing plants have well-developed stems, leaves, and rootsas well as vascular tissues. They grow very well in temperate regions. Gymnospermsconsist of only around 550 different species but they rank high among the economicallyimportant plants. Have you heard? …that the oldest living tree today is a Gymnosperm? It is found in Eastern California and is more or less 4,997 years old. - 18 -

Look at the illustrations on the following pages. Are you familiar with all the plantsillustrated? Examine the plants more closely. Which among the four is found in yourlocality? There are four groups of cone-bearing plants but not all of them are found here in ourcountry. They are as follows:Ginkgos Originally Ginkgos have 16 species,but now there is only one surviving,species, Gingkgo biloba or maiden hairas it is popularly called. This is a largetree with numerous spreading branches.Leaves are fan-shaped with parallel typeof leaf venation. The female plant formsseeds that give off a pungent odor, similarto rancid butter. This plant is abundant inChina and Japan. An illustration ofGinkgo biloba is found at the right. Figure 12. Ginkgo biloba www.cccmkc.edu.hk/~kei-kph/.../Gymnosperms.htmGnetumsThese plants resemble the flowering plants moreclosely. Gnetums are believed to be the ancestors of theflowering plants. They have cones that resemble flowers.They are usually smaller compared to Ginkgos that formlarge trees. Their leaves are with parallel venation similar tothe compound leaves of cycad or \"pitogo\" plant. Theseplants are not common here in our country. Examples ofthese are Gnetum, Ephedra and Welwitschia (found onlyin the deserts of South Africa). Since these plants are rare,just study Figure 13 and do the simple activity that Figure 13. Gnetumfollows. www.cccmkc.edu.hk/~kei-kph/.../Gymnosperms.htm - 19 -

Do this: Since the plants under the first two groups, the Ginkgos and Gnetums are not common and available, just examine closely the diagrams on pages 18 and 19 and compare them as to: 1. shape of leaves 2. type of venationCycads These are cone-bearing palm-like trees with thick stems. The leaves are large and“compound” or composed of several small leaf–like parts. These are the plants that areusually used during palm Sunday together with the young leaves of coconut trees. Femaleplants are distinct from the male plants. Male and female cones look different and may befound in two separate plants. They grow well in tropical countries like ours. All plantsbelonging to this group are called cycads. Examples of these are pitogo and oliva or peaceplant. Look at the samples of male and female cycad plants on the next page. Take note ofthe size of the cones.Pine Group Figure 14. Male and Female Cycads www2.junglemusic.net/show_cycadlist.asp This represents the biggest group of gymnosperms found in many parts of the world.Just like all the other plants we discussed, they all bear cones. Here in our country, themost common ones are the pine trees. There are only two species of pine trees found in ourcountry. They are Pinus insularis and Pinus merkusii. Some of these pine trees arefound not only in Baguio but in other parts of the Philippines like Zambales, Mindoro and in - 20 -

some parts of Mindanao. The conifers are large, tall trees with highly branched stems. Theleaves are usually scaly and needle-like. Since only pine trees are available here in ourcountry, we will focus on this plant. Examine carefully the two types of pine cones: Try this: Compare the male and female pine cones. How do they differ? Do you have these at home? You can buy these in department stores especially during the Christmas season. Or, if you live in Baguio City or in places with pine trees, you can see them on the branches or pick them up when they fall to the ground. Try to detach some of the seeds or scales. They are hard. Each of the seeds can grow into another young pine tree. Locate the seeds in the diagram and notice how they look like. Do you know? …that the biggest and tallest trees in the world are found in California, USA? One tree in Humboldt County, California with a height of 111.6 meters or 366.2 feet is believed to be the tallest conifer in the world. The other species usually referred to as “big tree” or giant red wood is confined at California’s Sierra Nevada. The scientific name is Sequoiadendron giganteum or simply called as sequoia. The tree is enough to build 75 five-room mansions or enough to make 20 billion toothpicks.Figure 15Female Cones (Seeds Exposed) www.naturalsciences.org/.../pinecones.htmlRemember:Cone-bearing plants are vascular plants.Cone bearing plants produce seeds from where the embryooriginates.Cone–bearing plants are divided into 4 groups: thecycadophyta, ginkgophyta, gnetophyta and coniferophyta. - 21 -

What you will do Self-Test 4.1Direction. Answer the following questions briefly:1. Why are gymnosperms referred to as plants with naked seeds? ______________________________________________________________________2. Where do you find the tallest tree in the world? How tall and big is it? ______________________________________________________________________3. Which among the cone-bearing plants are very common in Baguio City? ______________________________________________________________________4. Which species of pine trees are found in the Philippines? ______________________________________________________________________5. What are the economic importance of cone-bearing plants? ______________________________________________________________________ Key to answers on page 29.Lesson 5. The Flowering Plants When you bite into a chico or guava you are eating part of an angiosperm.Angiosperms or flowering plants are vascular plants with seeds usually found inside a fruit.There are around 250, 000 different species of flowering plants. Recall that cone-bearingplants like the pine trees are the opposite, their seeds are usually found outside. Find out! Get an uncooked peanut still in its shell. Open the shell. Remove the thin covering of the seed. Carefully open the seed and look for a small hump on half of the seed. This is the embryo or the baby plant. If you examine this closely you will note the future leaves, root and stem. Figure 16. Peanut seed explanationguide.info/meaning/Peanut.html - 22 -

There are two kinds of flowering plants based on the number of seed leaves orcotyledons: the monocot and the dicot. Monocot and dicot are shortened forms ofmonocotyledon and dicotyledon. A cotyledon is a seed leaf inside a seed. It is calledthe baby food for the baby plant. Monocots have one seed leaf inside a seed while dicotshave two. Let us examine further the differences between a monocot and a dicot plant. Workon another activity below. What you will do Activity 5.1 Comparing Dicot and Monocot Plants Get a branch of a gumamela plant with flower and an orchid plant with flower(preferably Dendrobium). Start your study with the gumamela. Closely examine the plant.Start with the leaf. Observe the veins. How are they arranged? Now, focus on the flower.The flower is composed of five colored petals. Look at the sepals. They are the green leaf-like parts at the base of the petals. Try to count them. How many are there? Look at thestigma. There are five of them in the flower. The stigma is located at the tip of the flower.The anther and other parts of the flower are also visible. In case you have difficulty locatingthe parts, refer to the drawing below. If you are through with the gumamela, shift to theorchid plant that you have and do the same as you did with the gumamela plant.Answer this:1. Compare the type of leaf venation or arrangement of veins in the two plants. Do they differ? ______________________________________________________________________2. How many petals are there in the gumamela flower? In the orchid? ______________________________________________________________________3. How many stigma did you find in each flower? ______________________________________________________________________ Key to answers on page 29. - 23 -

Figure 17. Monocot plant and dicot plant www.ezd-inc.com/.../pages/gumamela.html Let us now look at Table 1 for the differences between a monocot and dicot plant.Note that differences could be external or internal. Table 1 Type of Type of Number of Arrangement Type of leaf Type of root flowering flower cotyledon of vascular venation system plant Floral parts bundles Parallel Diffused orMonocot in 3’s (e.g leaf veins fibrous no. of petals) one seed ScatteredDicot Floral parts leaf vascular Netted leaf Taproot in 4’s or 5’s bundles veins system Two seed Vascular leaf bundles in rings or circular arrangementAssignment: Collect at least 10 flowering plants with complete plant parts and examine themcarefully. Make sure that your collection will include the two types of flowering plants.Compare them as to: a. Arrangement of veins b. Root system c. Number of petals d. Number of cotyledons - 24 -

Write your observations using this table.Name of plant Type of leaf Type of root No. of petals No. of venation system cotyledons Let’s Summarize 1. Plants are classified into non-vascular and vascular plants. 2. There are seven major categories of classification. 3. Kingdom is the highest level with species as the smallest. 4. Bryophytes refer to a group of non-vascular plants; the first non-vascular land plants. 5. Ferns are the first vascular land plants. 6. Fern allies include the whisk ferns, club mosses, and horsetails. 7. Gymnosperms are plants that bear naked seeds; or plants with seeds found outside. 8. The biggest and tallest tree is a gymnosperm. 9. Gymnosperms are cone-bearing plants. 10. Pine trees, yew, cedars, firs are examples of gymnosperms. 11. The reproductive cells of gymnosperms are found in the cones. 12. Flowering plants usually have seeds inside a fruit. 13. There are two types of flowering plants, the dicot and the monocot. 14. Dicots have 2 cotyledons, while monocots have only one. 15. Dicots also have a taproot system, netted venation, and flowers of multiples of 3’s or 5’s.Did you enjoy it? The module is quite long, you see, there are many plants, and to covereverything will take time. Anyway congratulations for a job well done! Now let’s see howmuch you have learned from the lesson. Answer the posttest below. - 25 -

PosttestMultiple Choice. Choose the letter of the correct answer. Write the chosen letter on aseparate sheet of paper.1. It refers to the branch of science that deals with the grouping, ordering, and naming ofliving things.a. Anatomy c. Embryologyb. Ecology d. Taxonomy2. There are seven major biological levels of classification. Which is the biggest unit ofclassification.a. family c. kingdomb. genus d. species3. Who was the first Swedish naturalist to classify living things? This man is regarded asthe father of Taxonomy.a. Anton van Leewenhoek c. Gregor Mendelb. Carolous Linnaeus d. Robert Hooke4. What do you call the type of classification that is based on similarity of structures?a. artificial c. naturalb. classical d. superficial5. Vascular plants produce the tallest and biggest trees in the world. Non-vascular plantsare small and cannot grow as tall as vascular plants. What could be the reason for this?a. absence of roots c. deficient nutrientsb. absence of water d. absence of vascular bundles6. Vascular plants are plants with tissues for transport of water, minerals and food for theplant. What are these transport tissues?a. Collenchyma and sclerenchyma c. sclereids and sclerenchymab. parenchyma and collenchyma d. xylem and phloem7. Plants are found in almost all types of habitat. Which among the following habitats isNOT favorable for the growth of mosses?a. damp soil c. dry and unshaded placesb. moist rocks d. trunks of trees in a forest8. All of the following are vascular plants EXCEPT:a. fern c. mangob. liverworts d. teak - 26 -

9. What reproductive structures are found in the female cones?a. anther c. pollenb. ovule d. spores10. What type of vascular arrangement do find in a dicot plant?a. alternate c. scatteredb. circular d. triangular11. How many cotyledons are there in a peanut seed?a. 1 cotyledon c. 3 cotyledonsb. 2 cotyledons d. 4 cotyledons12. Vascular bundles help in the transport of substances in plants. What vascular bundletransports water and minerals upward in plants?a. collenchyma c. phloemb. parenchyma d. xylem13. Parallel type of venation is shown in which of the following plants?a. coconut c. peanutb. gumamela d. pilinut14. Which of the following plant is not a gymnosperm?a. fern c. gnetumb. ginkgo d. oliva15. The taproot type of root system is exhibited by which plant?a. grass c. palayb. orchid d. radish Got a perfect score? Check it out! Key to answers on page 30. - 27 -

Key to AnswersPretest1. c 6. c 11. b2. d 7. b 12. a3. b 8. b 13. b4. b 9. d 14. c5. d 10. c 15. aLesson 1Activity 1.11. The bases for grouping the plants are shape, color and texture.2. 83. To be more systematic in identifying the seeds.Activity 1.21. Possible answer – terrestrial are the most common plants.2. Possible answer – aerial and aquatic plants3. Possible answer – few.Self-Test 1.11. kingdom2. vascular plants3. xerophytes4. species5. herbaceousLesson 2Self-Test 2.1Matching Type1. d2. e3. b4. c5. a - 28 -

Lesson 3Activity 3.11. Possible answer – few-to many2. Possible answer – mostly common3. Possible answer – mostly shaded places4. Possible answer – some have mature leaves or frondsSelf-Test 3.11. The horsetail.2. Psilotum.3. Undersurface of leaves.4. They produce thousands of spores.5. They are used as medicine, food and ornamentals.Lesson 4Activity 4.1Possible answers:Name of plant Height Habit Leaf characteristic Upright BipinnatelyCycad Around 1-1.5 m compound Bushy SimplePodocarpus Around 2 meters Bushy and tapering Needle-shapedPine tree Around 5 meters or moreSelf-Test 4.11. It is because the seeds are not located inside the fruit, they are outside.2. In California, USA3. Benguet pine.4. Pinus insularis & Pinus merkusii.5. They can be used for building houses, ornamentals and household materials.Lesson 5Activity 5.11. Gumamela have the netted type of venation, while Dendrobium have the parallel type of venation.2. There are 5 petals in gumamela while there are 6 in Dendrobium.3. There are four stigma in gumamela while there are six in lilies. - 29 -

Posttest 6. a 11. b 7. c 12. b 1. c 8. d 13. a 2. d 9. d 14. a 3. c 10. a 15. a 4. d 5. dReferencesBooks:Balzer, L., Collins, A., Goodson, P., Lauer, L., Slesmik, I. & Alexander, G. (1984). Introduction to biology. Glenview, Illinois: Scott Foresman and Co.Biggs, A., Daniel, L. & Ortleb, P. (1994). Life science. Westerville, OH: Merrill Publishing Co., Mcmillan/McGraw – Hill.Campbell, N.A. (1996). Biology. (4th ed.) California: Benjamin Cummings Publishing Company.Mauseth, J.T. (1996). Botany. Florida, USA. Harcourt Brace and Company.Miller, K.R. & Levine, J. (1991). Biology. Massachusetts, USA: Prentice Hall.Stern, K.R. (1994). Introductory plant biology. USA: Wm. C. Brown Publishers, Inc.Wong, H.K. & Dolmatz, M.S. (1986). Biology: The key ideas. New York, USA: Globe Book Company, Inc. - 30 -

Electronic Sources:http:www.sciencedaily.com/encyclopedia/bryophyteshttp:webjay.cuny.edu/acarpi/NSC/13-cell.htmwww.scenicviewsstudio.com/natur...www.mybitoftheplanet.com/wildli...www.ucmp.berkeley.edu/plants/an...http:www.sciencedaily.com/encyclopedia/bryophyteswww.home.aone.net.au/.../bpenmar.htmlwww.herbs2000.com/herbs/herbs_club_moss.www.pocketflora.com/.../ferns.htmwww.cccmkc.edu.hk/~kei-kph/.../Gymnosperms.htmwww2.junglemusic.net/show_cycadlist.aspwww.naturalsciences.org/.../pinecones.htmlexplanationguide.info/meaning/Peanut.htmlwww.ezd-inc.com/.../pages/gumamela.html - 31 -

Module 17 Animals Without Backbones What this module is about This is the first module regarding The Diversity of Animals. This covers all theanimals without backbones. The second module focuses on animals with backbones. Allthe modules are especially prepared to equip you with the knowledge about animals. Youwill see how they differ from one another in size, form, structure and habitats. There are 5 lessons in this module:  Lesson 1 – How Are Animals Classified?  Lesson 2 – The Sponges and Cnidarians  Lesson 3 – The Flatworms, Roundworms and Segmented Worms  Lesson 4 – The Soft-bodied and Joint-legged Animals  Lesson 5 – The Spiny-skinned Animals What you are expected to learn After going through this module, you are expected to: 1. Identify animals. 2. Give the characteristics of animals. 3. Describe how animals are classified. 4. Identify the following invertebrate animals: a. sponges b. cnidarians c. flatworms, roundworms, and segmented worms d. soft-bodied animals e. arthropods f. echinoderms 5. Describe the following invertebrate animals: a. sponges b. cnidarians c. flatworms, roundworms, and segmented worms d. soft-bodied animals e. arthropods f. echinoderms 6. Explain the habitats and importance of the different groups of animals.

What to do before (Pretest)Test I. Multiple Choice. Choose the letter of the correct answer. Write the chosen letteron a separate sheet of paper.1. Animals show characteristics that are common to them. Which of the following is NOT acharacteristic ability of animals?a. ability to breathe c. ability to produce their own foodb. ability to digest food d. ability to move from one place to another2. Which of the following is a primary characteristic of sponges?a. antennae c. suckersb. pores d. tentacles3. In the binomial system of classification, organisms are given two names. What is itcomposed of?a. family and genus name c. order and genus nameb. genus and species name d. local and international name4. Which among the following animals has many pores or openings in its body?a. ascaris c. spongeb. earthworm d. tapeworm5. Mollusks with two valves are also called: c. trivalves a. bivalves d. univalves b. gastropods6. Which among the following animals has different canal systems?a. earthworm c. spongeb. sea anemone d. tape worm7. All of the following are parasitic worms except:a. ascaris c. hookwormb. earthworm d. tapeworm8. Jellyfishes are noted for their powerful tentacles. What are their tentacles for?a. for excretion c. for reproductionb. for digestion d. for capturing food and defense9. The number of body regions in insects is:a. one c. threeb. two d. four -2-