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7 SCIENCE Quarter 2 – Module 6 Reproduction: The Continuity of Life This instructional material was collaboratively developed and reviewed by educators from public schools. We encourage teachers and other education stakeholders to email their...

7 SCIENCE Quarter 2 – Module 6 Reproduction: The Continuity of Life This instructional material was collaboratively developed and reviewed by educators from public schools. We encourage teachers and other education stakeholders to email their feedback, comments, and recommendations to the department of Education, Schools Division of Cebu City. We value your feedback and recommendations. 1 Science - Grade 7 Quarter 2 - Module 6: Reproduction: The Continuity of Life Second Edition, Revised 2021 Republic Act 8293, section 176 states that: No copyright shall subsist in any work of the Government of the Philippines. However, prior approval of the government agency or office wherein the work is created shall be necessary for exploitation of such work for profit. Such agency or office may, among other things, impose as a condition the payment of royalties. Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names, trademarks, etc.) included in this module are owned by their respective copyright holders. Every effort has been exerted to locate and seek permission to use these materials from their respective copyright owners. The publisher and authors do not represent nor claim ownership over them. Writer/Compiler: RAQUEL A. CAPURAS, MT-I, Abellana National School Content Editors: Dr. Febelyn B. Bendulo, PSDS, ND 5 Mrs.Nezel B. Leorag, Principal I, Tagba-o National High School Language Editor: Mrs. Nenita A. Nacional, Principal 1, Pardo Extension ES Management Team: Dr. Rhea Mar A. Angtud, Schools Division Superintendent Dr. Bernadette A. Susvilla, Assistant Schools Division Superintendent Mrs. Grecia F. Bataluna, CID Chief Mrs. Vanessa L. Harayo, EPS-LRMS Dr. Raylene S. Manawatao, EPS, EPS-Science Printed in the Philippines by DepEd Cebu City Division, ROVII Office Address: Imus Avenue, Cebu City Telefax: (032) 255-1516 / (032) 253-9095 E-mail Address: [email protected] Department of Education Republic of the Philippines 2  Lesson Modes of Asexual and Sexual Reproduction Quarter : Second Quarter, Module 6 Content Standard : Demonstrate understanding of reproduction as being both asexual and sexual. Performance Standard : Employ appropriate techniques using the compound microscope to gather data about very small objects. Competency : Differentiate asexual from sexual reproduction in terms of a. numbers of individuals involved b. similarities of offspring to parents What I Need to Know The ability of an organism to reproduce new individuals is one of the characteristics that distinguish living things from nonliving things. This ability is called reproduction. In the previous module, you have already begun to explore the diversity of organisms. These organisms bring about the continuation of their own kind through reproduction. Although these organisms have different methods of reproduction, every method leads to the beginning of a new life. This module discusses the different modes of reproduction in representative plants, animals, and microorganisms. Discussions are included in this module to help you understand the different ways that organisms reproduce and differentiate the offspring resulting from each mode of reproduction. At the end of this module, you are expected to: 1. Differentiate asexual from sexual reproduction; 2. Distinguish the ways by which plants and animals reproduce asexually and sexually; and 3. Give the importance of asexual and sexual reproduction as essential mechanisms that ensure the continuity of the species. 3  What I Know Pre-Assessment Directions. Read the questions carefully. Write your answers on a separate sheet of paper. 1. Which of the following structures are NOT involved in asexual reproduction? A. Gametes B. Roots C. Stem D. Tuber 2. A farmer grew only one type of onion. All the onion plants died from the same disease. What can be said of this onion plant population? A. The onion plants were genetically identical. B. Only few plants were resistant to the disease. C. All the onion plants were resistant to the disease. D. The onion plants were genetically different from each other. 3. A farmer wants to propagate a good variety of crop which maintains all its desirable traits. Which of the following methods should be used? A. self-pollination B. vegetative propagation C. growing seeds produced from this variety. D. cross-pollinating this crop with another good variety and growing the seeds resulting from the cross 4. Which of the following statements is TRUE about asexual reproduction? A. Only one parent is required. B. The offspring produced is genetically unique. C. Male and female parents are needed to produce offspring. D. It is the process in which new organisms are produced from two individuals with different sexes. 5. What type of asexual reproduction when an organism undergoes a period of growth then splits in two separate organisms? A. budding B. fission C. fragmentation D. spore formation 6. What process of reproduction by which most bacteria are reproduced? A. budding C. binary fission B. fragmentation D. spore formation 7. Which of the following statements is TRUE regarding vegetative propagation? Vegetative propagation occurs __________. A. producing genetically similar plants B. naturally producing genetically similar plants C. naturally and artificially producing genetically different plants D. naturally and artificially producing genetically identical plants 8. A sperm cell unites with an egg cell to form a zygote. Which process is taking place? A. asexual reproduction C. pollination B. fertilization D. vegetative propagation 9. In sexual reproduction, what is the source of the genetic material in a zygote? A. an egg cell only C. a pollen and a sperm cell B. a sperm cell only D. an egg cell and a sperm cell 10. Which species can produce offspring that is genetically different from its parents? A species that ___________. A. has few variations C. reproduces asexually B. reproduces sexually D. competes with a similar species 4 11. Which is NOT a characteristic of sexual reproduction? A. Offspring is genetically identical with the parent. B. Gametes from two parents unite to form a zygote. C. Offspring is different from their parents and sibling. D. Genetic variability of offspring help to ensure survival in changing environmental conditions. 12. In what way flowers help to reproduce angiosperms? Flowers ____________. A. support and protect the gametes B. are important sources for human food C. store nutrients needed for the plant to grow D. help attract organisms needed for pollination 13. Which of the following statements is TRUE about external fertilization? I. It is a feature of reproduction in which fertilization takes place outside an organism’s body. II. It is a feature of sexual reproduction in which sperm cells are transported into the oviducts of the female. III. It usually occurs in aquatic environments where both eggs and sperm are released into the water. IV. It happens during the process of spawning where one or several females release their eggs and the male(s) release sperm in the same area, at the same time. A. I and II only C. I, III, and IV only B. III and IV D. I, II, III, and IV 14. For fertilization to occur in most flowering plants, insects or other animals must transport the pollen to the pistil. What must be taking place for fertilization to occur? A. The plant must be exposed to sunlight during pollination. B. The sperm cell in the pollen tube must reach the egg in the ovule. C. The egg in the ovule must reach the top of the stigma where pollen is trapped. D. All of these are correct. 15. Which of the following statements is CORRECT? A. The radicle of the seed grows upwards. B. After fertilization, the ovule forms a seed. C. The stamen is the female part of the flower. D. The embryo of the seed consists of the ovule and radicle. What’s In Activity 1 Characteristics of Living Organisms Directions: Match each term in Column B with its definition in Column A. Write the correct letter of your answer on a separate sheet of paper. COLUMN A COLUMN B 1. an action taken by an organism causing a change A. excretion of position or place B. growth 2. the chemical reactions in cells that break down C. movement nutrient molecules and release energy for metabolism D. nutrition 3. a permanent increase in size and mass E. reproduction 4. the process of producing offspring F. respiration 5. removal of the waste products of metabolism from organisms 6. intake of substances for energy, growth, and development 5  What’s New Activity 2 Vegetative Propagation DIRECTIONS: Read the story carefully and answer the questions below on a separate sheet of paper. Potato and Friends Narrator: In the farm, Potato is waiting so long to her friend Strawberry. Potato: What happen to her? Narrator: After ten minutes, Strawberry was grasping her breath going to Potato’s place. Strawberry: I am sorry, Potato. I am late. My cousins and I are playing in our house, and they are here to join us. Potato: Oh! That is good. Strawberry: Yeah! it will be good if we are many. By the way, here are my cousins; Onion, Gladiolus, and Ginger. Potato: Hi! Good to see you. Ok, let’s go to my house. I guess we need to eat first before we harvest. Let us go! Narrator: After eating, they decided to play first before they go back to the farm. They play spin in a bottle. Onion: You are a good cook, Potato. The food is so delicious. Potato: Really! Thank you. Ok, let us start the game. So, Potato start spinning the bottle. If the mouth of the bottle points to you, you will talk about your secret or your unique characteristics. Agree? Narrator: Everyone said yes, and the game starts. Potato: Oh! So lucky I am the first. Hmmmm…. well, I am a tuber, a specialized stem, usually short and thickened and typically grow below the soil. Most tubers bear minute scale leaves, each with a bud that has the potential for developing into a new plant. That is it. Ok, let us continue. I will spin now. Ginger: Oh! Lucky me. Well, I am a type of plant stem situated either at the soil surface or underground that contains nodes from which roots and shoots originate. I am a rhizome that tends to grow horizontally instead of vertically. Rhizomes grow under the soil and new growth may occasionally sprout at different angles. Because it is found under the ground, a misconception to me is I am part of the root. However, I am a stem that grows beneath the surface of the ground. Ok, my turn to spin. Who is next? Gladiolus: It is me. I am perennial flowering plant, and I am a corm. Corm is a short vertical, fleshy, underground stem that acts as a food storage structure in certain seed plants. I reproduce by means of small corms called cornels, which will develop at the base of the corms and grow into mature corms over a period of few years. That is all. My time to spin. Here we go!!! Onion: Yes! It’s me Hmm…I am a bulb, my stem is shortened down to a disc, often called the basal plate from which roots arise around the edge. My spin. Strawberry: Oh! My turn. I am pretty, just kidding. Well, my family called me stolon or runner. I grow at the soil surface or just below the ground that forms adventitious roots at the nodes, and new plants from the buds. 6  Potato: Maybe we can stop the game. We can continue this later. Let us go back to farm and start harvesting the fruits and vegetables. I think you will enjoy harvesting fruits and vegetables in our farm. Strawberry: Definitely. Let us go, my dear cousins. Narrator: After cleaning, they go to the farm. All of them have fun harvesting the whole afternoon. Q1. How do the following plants reproduce as mentioned in the story? a. Potato - ____________________ b. Onion - ____________________ c. Ginger - ____________________ d. Gladiolus - ____________________ e. Strawberry - ____________________ Q2. What type of reproduction is exhibited by the plants in the story? ______________________________________________________________ Q3. Why do plants need to reproduce? ______________________________________________________________ Activity 3 Which Part Is It? Directions: Study the parts of the flower shown below and identify which part is being described. Write your answer on a separate sheet of paper. Fig. 1. A typical complete flower and its reproductive structure. 1. the part of the flower that contains the ovules 2. the male part of a flower 3. flowers that have both male and female parts 4. a threadlike structure that holds up the anther 5. a tube-like structure that holds up the stigma 6. the female part of the flower 7. when fertilized, this becomes the seed 8. where pollen is reproduced 7  What is It Asexual reproduction is a mode of reproduction in which a new offspring is produced by a single parent. The new individuals produced are genetically and physically identical to each other. Below is a table showing the different modes of asexual reproduction, its description, and examples. Modes of Asexual Description Examples Reproduction Budding A new individual forms as an Yeast, hydra, and outgrowth of the parents, then sponges the outgrowth separates from a parent and becomes a new individual. Fission The cell divides to form identical Singled-cell green daughter cells, and each algae daughter cell continues to grow until it becomes as large as the parent cell. Fragmentation An offspring grows from a piece Starfish, hydra of its parents. Regeneration An organism can regrow a lost Starfish, earthworm, limb or can grow a whole other hydra organism on a cut off piece Spores formation It is a type of reproduction which Bread molds, occurs mainly in non-flowering mushrooms plants like in fungi. The parent plant produces thousands of fruit-like structures called spores which then grow into new plants. Vegetative A new plant can form from the Strawberry, onions, root, stem, or leaf of an already Gabi, potato, existing plant. 8 The table below shows the different types of Vegetative Propagation in Plants Types Description Example 1.Runner/Stolon It is an aboveground stem that grows Bermuda grass, horizontally along the surface when the strawberry stem touches the ground. Buds from the stem form roots and leaves, and a new plant develops. 2.Rhizome It is an underground stem that grows Ginger horizontally along the surface; shoots from buds at nodes of the stem develop into a new plant. 3.Tubers These are enlarged and thickened Potato underground stems with buds or eyes. 4.Bulbs They have a short, underground stem Onion and thick, fleshy leaves that are colorless. A bulb can reproduce several smaller bulbs, each of which can grow into a new plant. 5.Corm It is an enlarged, short, underground Gabi stem that stores food. Corms resemble bulbs but do not have thick, fleshy leaves. New corms develop from the stem of an old corm to produce new plants. Sexual Reproduction is a form of reproduction that involves two parents. Parents produce reproductive cells called gametes. Gametes are formed during meiosis. Meiosis will be discussed in Grade 8. Female gametes are called ova or egg cells, and male gametes are called sperm. Gametes are haploid cells, and each cell carries only one copy of each chromosome. Under favorable conditions, sperm and egg cell unite in a process known as fertilization. The resulting fertilized egg, or zygote, contains genes from both parents. Hence, the offspring have unique combinations of genes. Offspring of sexual reproduction differ genetically from their siblings and species extinction is unlikely to happen. SEXUAL REPRODUCTION IN FLOWERING PLANTS The flower is the reproductive organ in flowering plants. Flowers have structures that produce the gametes necessary for reproduction. Look at the parts of the gumamela flower below. Fig. 1. A typical complete flower and its reproductive structure 9  Parts of A Gumamela Flower A. Essential Parts or the Reproductive Parts 1. Stamen – is the male reproductive part of the flower and is collectively called as androecium. It consists of the following: a. Filament – is the slender stalk b. Anther – is a knoblike structure located at the tip of the filament that produces colored pollen grains. Pollen contains sperm nuclei, which are essential for reproduction. 2. Pistil – is the female reproductive part of the flower and is collectively called as gynoecium. Pistil is also known as carpel. It is usually flask-shaped and consists of the following: a. Stigma – is an expanded tip of the style and is usually sticky which receive the pollen grains b. Style – is the long, slender stalk which supports the stigma c. Ovary – is a swollen base where the style ends and that bears the ovules. The ovules will later become seeds. B. Sterile Parts/ Non-Essential parts of a Flower- these parts are for support and help in attracting insects for pollination. 1. Calyx- is a collection of sepals. It is green, leaf-like structures that cover and protects the rest of the flower. It also supports the other parts when the bud opens. 2. Corolla- is found inside the calyx. It usually consists of one or more petals. It is often, but not always bright-colored. Corolla together with calyx frequently attracts insects. It may also help protect the inner part of the flowers. 3. Peduncle/ Pedicel- it is a stalk that attaches the flower to the stem. 4. Receptacle- is the bulging extension of the pedicel TYPES OF ANIMAL FERTILIZATION 1. External fertilization It is characterized by the release of both sperm and egg into an external environment. Many aquatic animals simply release their eggs and sperm into the water. The water becomes the medium in which the sperm swims to unite with an egg. The female releases several millions of tiny eggs into the water. The males, too, discharge almost at the same time in the same spot. Through water movement, the sperm and egg mix. This way the chances of fertilization are greater. 2. Internal fertilization It is when the male deposits his sperm directly into the female's body. In internal fertilization, small, motile sperm are introduced into the female reproductive tract during mating. The sperm cells swim up the reproductive tract until they encounter a mature egg or oocyte in an oviduct where fertilization occurs. Animals that undergo this type of reproduction produce offspring in any of the following ways: oviparous, ovoviviparous, and viviparous. 10  What’s More Activity 4 Sexual Reproduction and Development in Different Animals This activity will help you understand that there is a difference among animals in terms of reproduction and development. Directions: Go over the list of animals in the table and describe in the appropriate column their respective breeding place, type of fertilization, and development of the embryo. Write your answers on a separate sheet of paper. Reproduction and Development in Selected Animals Animals Breeding Place Fertilization Development of Embryo (Land or Water) (External or (Outside or Inside the Internal) female’s body) Example: Milkfish water external outside Frog Chicken Dog Turtle Human What I have learned Activity 5 Compare and Contrast! Direction: On a separate sheet of paper, make a Venn Diagram to compare and contrast asexual and sexual reproduction using the term/s provided inside the box. bacteria, amoeba offspring are not identical human, dogs offspring grow and develop lower organisms one parent more complex organisms produce offspring critical for survival of the species quicker time period slower time period offspring are identical two parents 11  What I Can Do Directions: Read the given situation below and answer the question briefly on a separate sheet of paper. For your guide in answering, refer to the rubrics below. An organism lives in an environment that has a nice and stable summer season. This season provides ample food, shelter, and water. However, the environment is harsh and cold during wet season and resources become scarce. Considering these environmental conditions, how will the organism take the challenge from extinction? Rubric for Scoring: Basis 3 2 1 Ideas Ideas presented is Ideas presented is Ideas has no clear clear and focused not well defined sense of purpose Organization Information is Information is Information is not relevant and in somewhat relevant relevant logical order Word choice The choice of The choice of words The choice of words is words is accurate is not so accurate not accurate Spelling and Spelling and Only few errors in Many errors in spelling punctuation punctuations are all spelling and and punctuations are correct punctuation is observed observed Assessment Directions: Write the letter that corresponds to your answer on a separate sheet of paper. 1. Which of the following does NOT belong to the group in terms of reproduction? A. chicken B. hydra C. mushroom D. yeast 2. What type of asexual reproduction is presented when an offspring grows from a piece of its parent? A. budding C. fragmentation B. fission D. spore formation 3. What type of vegetative propagation where a specialized stem grows underground like the bamboo and Bermuda grass? A. budding B. corms C. grafting D. rhizomes 4. Which correctly describes asexual reproduction? It is a process of reproduction which involves _______. A. fertilization C. only one parent B. pollination D. two or more parents 5. In certain bacteria and yeasts, an offspring grows out of the body of the parent and detached as it grows further. What type of asexual reproduction is demonstrated? A. Budding C. Fragmentation B. Fission D. Spore Formation 6. One of the most serious rhizome-born diseases, the bacterial wilt, hit Mie’s ginger garden. Why did all the ginger plants die from the disease? It is because _________. A. they were genetically identical B. they were resistant to the disease C. only few of them were resistant to the disease D. they were genetically different from each other 12 7. Which of the following statements is NOT TRUE regarding vegetative propagation? It refers to __________. A. rapid propagation of plants B. production of genetically similar plants C. production of genetically different plants D. easy and cheaper method of reproduction 8. What is the function of the ovaries in a flowering plant? They produce ________. A. male gametes C. colored pollen grains B. female gametes D. male and female gametes 9. What happen to the female parts of the flower after fertilization? The ovules become ___. A. seeds and the rest become the fruit B. fruit and the rest become the seeds C. seeds and the rest become the stored food D. the stored food and the rest become the seeds 10. What is the other term for sex cell (egg or sperm)? A. Gamete B. Gene C. Offspring D. Zygote 11. Which analogy fits the statement below? Seeds are mature _______, fruits are mature _______. A. ovaries, stamen C. ovules, ovaries B. ovaries, ovules D. ovules, stamens 12. Which of the following is TRUE about sexual reproduction? A. Only one parent is involved. B. Genetically identical offspring are produced. C. It puts animals at an evolutionary disadvantage in terms of variation. D. It involves the exchange of genetic material between two individuals. 13. What type of reproduction passes genetic information to the future generations? A. Asexual reproduction C. Both sexual and asexual B. Sexual reproduction D. none of the above 14. In external fertilization, where do the egg and sperm cell unite? A. body or womb B. environment C. ovary D. parents 15. In internal fertilization, where do the egg and sperm cell unite? A. body or womb B. environment C. ovary D. parents Additional Activities Direction: Fill in the blanks with the correct word/s to complete the sentence. Use a separate sheet of paper. 1. Vegetative propagation is a kind of __________ reproduction. 2. In asexual reproduction, the parent and the resulting offspring have the same genes and traits. In other words, they are __________. 3. In ________ reproduction, two parents are involved and the offspring have unique combinations of genes. 4. Yeast, hydra and sponges reproduce through _________. 5. The process in which organisms replace or restore their lost or damaged parts is called _________. 6. The union of an egg cell and a sperm cell will result into a _________. 7. The stamen is the pollen-producing reproductive organ of a flower. Collectively the stamens form the __________. 8. Female gametes are called ______ or egg cells, and male gametes are called sperm. 9. The _________ is the reproductive organ in flowering plants. 10. The male reproductive part of the flower is the _________. 13  Answer Key Lesson 1 Modes of Asexual Reproduction What’s In 1. c 2. f 3. b 4. e 5. a 6. d What’s New Activity 2 Q1 a. tubers b. bulb c. rhizome d. corm e. stolon/runners Q2. Vegetative reproduction of plants. A natural method of producing new plants. Q3. reproduction is essential for continuation of species Activity 3 which part is it? 1. ovary 2. anther 3. perfect 4. filament 5. style 6. pistil 7. ovule 8. stamen Activity 4 what’s more Animals Breeding Place- Fertilization Development of Embryo Land or Water External or Internal (Outside or Inside) the female’s Body Milkfish water external outside Frog water external outside Chicken land internal outside Dog land internal inside Turtle water internal outside Human land internal inside What I have learned activity 5 Compare and Contrast What I Can Do (answer varies): essay Additional Activity 1asexual 2identical 3sexual 4budding 5regeneration 6zygote 7androecium 8ova 9flower 10stamen 14 References BOOKS Asuncion, Alvie J., Catalan, Maria Helen D.H., Catris, Letecia V., Flerido, Mariene B.,Gutierrez, Jacqueline Rose M., Mantala, Michael Anthony B., Maramag,Cerelina M., Mejia, Ivy P., Obille Jr. Eligio C.,Reyes, Risa L. Sebastian, Dulcelina O., Tan, Merie C., Treyes, Rodolfo S. SCIENCE GRADE 7 LEARNER’S MATERIAL. Philippines: Department of Education, 2017 Asuncion, Alvie J., Catalan, Maria Helen D.H., Catris, Letecia V., Flerido, Mariene B.,Gutierrez, Jacqueline Rose M., Mantala, Michael Anthony B., Maramag,Cerelina M., Mejia, Ivy P., Obille Jr. Eligio C.,Reyes, Risa L. Sebastian, Dulcelina O., Tan, Merie C., Treyes, Rodolfo S. SCIENCE GRADE 7 TEACHER’S GUIDE. Philippines: Department of Education, 2017 Fabunan, M. F. (2018) Sexual Reproduction and Fertilization-. Cross-Specialization Training of Grades 7 – 10 Science Teachers on their Non-Major Science Subjects Manual., ELECTRONIC RESOURCES ReviewGameZone.com. (n.d). Asexual and sexual reproduction. https://reviewgamezone.com/mc/candidate/test/?test_id=31367&title=Asexual% 20And%20Sexual%20Reproduction. Accessed January 02, 2021 Quizziz.com.https://quizizz.com/admin/quiz/56fc96a57359542075c77f44/asexual-vs- sexual- reproduction. Accessed January 02, 2021 Quizziz.com(n.d.)https://quizizz.com/admin/quiz/5825eb4f0a0d754977e8d185/asexu al-sexual-reproduction. Accessed January 02, 2021 Kesler Science, LLC. Sexual reproduction and asexual reproduction lesson plan- a complete science lesson using the 5E method of instruction. Accessed from https://www.keslerscience.com/sexual-reproduction-and-asexual-reproduction- lesson-plan-a-complete-science-lesson-using-the-5e-method-of-instruction/ Accessed on January 02, 2021 Lumen boundless biology. Reproduction method. Accessed from https://courses.lumenlearning.com/boundless-biology/chapter/reproduction- methods/. Accessed January 02, 2021 15