Tamil Nadu 10th Standard Science Book Solution | Lesson 17 – Reproduction In Plants And Animals

Lesson 17. Reproduction In Plants And Animals

Lesson 17. > Reproduction In Plants And Animals

I. Choose the best answer

1. The plant which propagates with the help of its leaves is __________.

1. Onion
2. Neem
3. Ginger
4. Bryophyllum

Ans ; Bryophyllum

2. Asexual reproduction takes place through budding in __________.

1. Amoeba
2. Yeast
3. Plasmodium
4. Bacteria

Ans ; Yeast

3. Syngamy results in the formation of __________.

1. Zoospores
2. Conidia
3. Zygote
4. Chlamydospores

Ans ; Zygote

4. The essential parts of a flower are __________.

1. Calyx and Corolla
2. Calyx and Androecium
3. Corolla and Gynoecium
4. Androecium and Gynoecium

Ans ; Androecium and Gynoecium

5. Anemophilous flowers have __________.

1. Sessile stigma
2. Small smooth stigma
3. Colored flower
4. Large feathery stigma

Ans ; Large feathery stigma

6. Male gametes in angiosperms are formed by the division of __________.

1. Generative cell
2. Vegetative cell
3. Microspore mother cell
4. Microspore

Ans ; Generative cell

7. What is true of gametes?

1. They are diploid
2. They give rise to gonads
3. They produce hormones
4. They are formed from gonads

Ans ; They are formed from gonads

8. A single highly coiled tube where sperms are stored, get concentrated and mature is known as

1. Epididymis
2. Vasa efferentia
3. Vas deferens
4. Seminiferous tubules

Ans ; Epididymis

9. The large elongated cells that provide nutrition to developing sperms are

1. Primary germ cells b
2. Sertoli cells
3. Leydig cells
4. Spermatogonia

Ans ; Sertoli cells

10. Estrogen is secreted by

1. Anterior pituitary
2. Primary follicle
3. Graffian follicle
4. Corpus luteum

Ans ; Graffian follicle

11. Which one of the following is an IUCD?

1. Copper – T
2. Oral pills
3. Diaphragm
4. Tubectomy

Ans ; Copper – T

II. Fill in the blanks

1. The embryo sac in a typical dicot at the time of fertilization is __________.

Ans ; 7 Celled

2. After fertilization the ovary develops into __________.

Ans ; Fruit

3. Planaria reproduces asexually by __________.

Ans ; Regeneration

4. Fertilization is __________ in humans.

Ans ; Internal

5. The implantation of the embryo occurs at about __________ days of fertilization.

Ans ; 6 – 7 days

6. __________ is the first secretion from the mammary gland after childbirth.

Ans ; Colostrum

7. Prolactin is a hormone produced by __________.

Ans ; Pituitary gland

III. (a) Match the following

III. (b) Match the following terms with their respective meanings

IV. State whether the following statements are True or False. Correct the false statement

1. Stalk of the ovule is called pedicle. ( False )

• Stalk of the ovule is called funiculus.

2. Seeds are the product of asexual reproduction. ( False )

• Seeds are the product of sexual reproduction.

3. Yeast reproduces asexually by means of multiple fission. ( False )

• Yeast reproduces asexually by means of budding.

4. The part of the pistil which serves as a receptive structure for the pollen is called as style. ( False )

The part of the pistil which serves as a receptive structure for the pollen is called as stigma.

5. Insect pollinated flowers are characterized by dry and smooth pollen. ( False )

• Wind pollinated flowers are characterized by dry and smooth pollen.

6. Sex organs produce gametes which are diploid. ( False )

• Sex organs produce gametes which are haploid.

7. LH is secreted by the posterior pituitary. ( False )

• LH is secreted by the anterior pituitary.

8. Menstrual cycle ceases during pregnancy. ( True )

9. Surgical methods of contraception prevent gamete formation. ( False )

• Surgical methods of contraception prevent gametes transportation.

10. The increased level of estrogen and progesterone is responsible for menstruation. ( False )

• The decreased level of estrogen and progesterone is responsible for menstruation.

V. Answer in a word or sentence

1. If one pollen grain produces two male gametes, how many pollen grains are needed to fertilize 10 ovules?

10 pollen grains are needed to fertilize 10 ovules.

2. In which part of the flower germination of pollen grains takes place?

The germination of pollen grains takes place in stigma.

3. Name two organisms which are reproduced through budding.

Hydra and yeast are the organisms which are reproduced through budding.
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4. Mention the function of endosperm.

Endosperm provides food to the developing embryo.

5. Name the hormone responsible for the vigorous contractions of the uterine muscles.

Hormone responsible for the vigorous contractions of the uterine muscles is oxytocin.

6. What is the enzyme present in acrosome of sperm?

The enzyme present in acrosome of sperm is hyaluronidase.

7. Whenis World Menstrual Hygiene Day observed?

Every year May 28 is observed as menstrual hygiene day.

8. What is the need for contraception ?

The need for contraception is control birth.

9. Name the part of the human female reproductive system where the following occurs. a. Fertilization b. Implantation

a) Fertilization

• occurs in the oviduct of the female genetal tract.

b) Implantation

• occurs in uterus.

VI. Short answer questions.

1. What will happen if you cut planaria into small fragments?

If I cut planaria into small fragments it will regenerate the organs and produce a new planaria.

2. Why is vegetative propagation practiced for growing some type of plants?

It has only mitotic division, no gametic fusion and daughter plants are genetically similar to the parent plant. So some plants grow by propagation practices.

3. How does binary fission differ from multiple fission?

4. Define triple fusion.

• In the fertilization, one sperm fuses with egg and forms a diploid zygote.
• The other sperm fuses with the secondary nucleus to form the primary endosperm nucleus.
• This fusion is called triple fusion.

5. Write the characteristics of insect-pollinated flowers.

• Insect pollinated plants characters are brightly coloured, have smell and nectar.
• The pollen grains are larger in size the exine is pitted and spiny.

6. Name the secondary sex organs in male.

The secondary sex organs in male are vas deferens, epididymis, seminal vesicle, prostate gland and penis.

7. What is colostrum? How is milk production hormonally regulated ?

• The first fluid which is released from the mammary gland after child birth is called as colostrum.
• Milk production from alveoli of mammary glands is stimulated by prolactin secreted from the anterior pituitary.
• The ejection of milk is stimulated by posterior pituitary hormone oxytocin.

8. How can menstrual hygiene be maintained during menstrual days?

• Maintaining menstrual hygiene is important for the overall health of women.

The basic menstrual hygiene ways are:

• Sanitary pads should be changed regularly, to avoid infections due to microbes from vagina and sweat from genitals.
• Use of warm water to clean genitals helps to get rid of menstrual cramps.
• Wearing loose clothing rather than tight fitting clothes will ensure the airflow around the genitals and prevent sweating.

9. How does developing embryo getsits nourishment inside the mother’s body?

• The placenta is a disc shaped structure attached to the uterine wall and is a temporary association between the developing embryo and maternal tissues.
• It allows the exchange of food materials, diffusion of oxygen, excretion of nitrogenous wastes and elimination of carbon dioxide.
• A cord containing blood vessels that connects the placenta with the foetus is called the umbilical cord.

10. Identify the parts A, B, Cand D

11. Write the events involved in the sexual reproduction of a flowering plant.
a. Discuss the first event and write the types.
b. Mention the advantages and the disadvantages of that event.

Pollination :

• Transfer of pollen grains from anther to stigma of a flower is called pollination.

Types of Pollination:

• Self-pollination
• Cross pollination

Self-pollination (Autogamy)

• Self-pollination is also known as autogamy.
• The transfer of pollen grains from the anther to the stigma of same flower or another flower borne on the same plant is known as self pollination. e.g. Hibiscus.

Advantages of self-pollination

• Self-pollination is possible in certain bisexual flowers.
• Flowers do not depend on agents for pollination.
• There is no wastage of pollen grains.

Disadvantages of self-pollination

• The seeds are less in numbers.
• The endosperm is minute. Therefore, the seeds produce weak plants.
• New varieties of plants cannot be produced.

12. Why are the human testes located outside the abdominal cavity? Name the pouch in which they are present.

• The formation of sperm is in a particular temperature which is less than our body temperature. So it is located in the outside of the body.
• The name of the pouch is scrotum.

13. Luteal phase of the menstrual cycle is also called the secretory phase. Give reason

• Corpus leuteum produces progestrone and its level increases followed by a decline if menstrual bleeding occurs.
• Uterine wall ruptures bleeding starts and infertilized egg is expelled.

14. Why are family planning methods not adopted by all the people of our country?

Uneducated, fear, not understanding the population explosion are the factors  affect the family planning methods.

VII. Long answer questions

1. With a neat labelled diagram describe the parts of a typical angiospermic ovule.

• The main part of the ovule is the nucellus which is enclosed by two integuments leaving an opening called as micropyle.
• ‘The ovule is attached to the ovary wall by a stalk known as funiculus.
• Chalaza is the basal part.

Structure of the Ovule

• The embryo sac contains seven cells and the eighth nuclei located within the nucellus.
• Three cells at the micropylar end form the egg apparatus and the three cells at the chalaza end are the antipodal cells.
• The remaining two nuclei are called polar nuclei found in the center.
• In the egg apparatus, one is the egg cell (female gamete) and the remaining two cells are the synergids.

2. What are the phases of the menstrual cycle? Indicate the changes in the ovary and uterus,

• Menstrual or Destructive Phase
• Follicular or Proliferative Phase
• Ovulatory Phase
• Luteal or Secretory Phase

VIII. Higher. Order Thinking Skills (HOTS)

1. In angiosperms the pollen germinates to produce a pollen tube that carries two gametes. What is the purpose of carrying two gametes when a single gamete can fertilize the egg?

• Vegetative cell degenerates and the generative cell divides to form two sperms(or male gametes).
• Tip of pollen tube bursts and the two sperms enter the embryo sac.
• One sperm fuses with the egg (syngamy) and forms a diploid zygote.
• The other sperm fuses with the secondary nucleus (Triple fusion) to form the primary endosperm nucleus which is triploid in nature.
• Since two types of fusion syngamy and triple fusion take place in an embryo sac the process is termed as double fertilization.
• After triple fusion, primary endosperm nucleus develops into an endosperm.
• Endosperm provides food to the developing embryo.
• The purpose of carrying two gametes is one is to form zygote another is to form endosperm to provide food to the devloping embryo.

2. Why menstrual cycle does not take place before puberty and during pregnancy?

• Before puberty and during development, the secretion of estrogen and progesterone are not secreted.
• So it does not form ovary.
• So menstrual does not take place before puberty and during pregnancy.

3. Read the following passage and answer the questions that follow

Rahini and her parents were watching a television program. An advertisement flashed on the screen which was promoting the use of sanitary napkins. Rahini’s parents suddenly changed the channel, but she objected to her parents and explained the need and importance of such advertisement.

a) What is first menstruation called? When does it occur ?

• The first menstruation is called menarche. It occurs at the age of 11 to 13 years.

b) List out the napkin hygiene measures taken during menstruation .

• The sanitary pad and tampons should be wrapped properly and discarded because they can spread infections.
• sanitary pad or tamnpon should not be flushed down the toilet.
• Napkin incinerators are to be used properly for disposal of used napkins.

c) Do you think that Rahini’s objection towards her parents was correct? If so, Why? ?

• The advertisement gives some knowledge about the napkin.
• How to use the napkin and what is the purpose of it.
• The advertisement is answers some more questions.
• It create the awareness among the females. So the object are correct.

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