How Do Organisms Reproduce ? : Complete Set of Questions



This set of questions contains all the possible concepts
which could be asked in the examination

Do Organisms Create Exact Copies of Themselves ?

Q.1 What is reproduction? What are its two types? Which one of the two confers new characteristics on the offspring’s and how?

Reproduction is the process of formation of new young individuals of the similar type of mature living being.

Reproduction is of two types:

(i) Asexual reproduction

(ii) Sexual reproduction

Only sexual reproduction confers new characteristics on the offspring because the process of DNA replication occurs in sexual reproduction. Mutations occur during DNA replication which give rise to variation, thus confers new characteristics on the offspring.


Q.2 How can you say that DNA copying an essential part of the process of reproduction?

The process of reproduction results in the production of offspring’s which are exactly similar to the parents. DNA copying is accompanied by cell division that gives rise to two cells. The exact blue print of body design is inherited in the offspring’s due to DNA replication in parent cell. Therefore, DNA copying is an essential part of the process of reproduction


Q.3 Reproduction is linked to the stability of the species. Justify your statement.

In reproduction, DNA passes from one generation to the next. Copying of DNA takes place with consistency but with minor variations. The consistency of DNA copying during reproduction is important for the maintenance of body design features that allow the organism to use that particular niche. This consistency leads to the stability of the species.Reproduction is therefore linked to the stability of populations of species.


Q.4 Mention any three advantages of variation in individuals.

(i) Variation helps in survival of species.

(ii) It is the basis of evolution.

(iii) It brings adaptation in individuals.


Q.5 What is the effect of DNA copying which is not perfectly accurate in the reproduction process?

During the process of DNA copying, some mutations are produced which give rise to useful, harmful or neutral variations in the offspring.


Q.6 Mention the information source for making proteins in the cell. What is the basic event in reproduction?

The DNA in the nucleus of a cell is the information source for making proteins. If the information is changed different proteins will be made. Different proteins will eventually lead to altered body designs. The basic event in reproduction is the creation of a DNA copy. Cells use chemical reactions to build copies of their DNA. This creates two copies of the DNA in a reproducing cell, and they will need to be separated from each other. DNA copying is accompanied by the creation of an additional cellular apparatus, and then the DNA copies separate, each with its own cellular apparatus.


Q.7 The process of combining DNA from two different individuals during reproduction may result in increased DNA content in each generation. How is this problem taken care of?

The special cells produced in individuals for reproduction have only half the number of chromosomes and half the amount of DNA as compared to the non-reproductive body cells. So, when these special cells, i.e., gametes combine, it results in re-establishment of the chromosome number and DNA content in the new generation.


Q.8 In tobacco plant, the male gametes have twenty–four chromosomes.

(i) What is the number of chromosomes in the female gamete?

(ii) What is the number of chromosomes in the zygote?

(i) 24 chromosomes

(ii) 48 chromosome


Q.9 Why do living organisms reproduce?

Reproduction provides-

(i) Stability to the population of species

(ii) Variations responsible for survival of a species over a period of time (evolution)

 

Modes of Reproduction Used by Single Organisms

Q.10 In what ways is binary fission different from multiple fission?


Q.11 Mention the common mode of reproduction found in (i) Amoeba (ii) Planaria

Amoeba — Binary fission in any plane.

Planaria — Transverse binary fission.


Q.12 Name any two types of asexual reproduction.

(i) Binary fission

(ii) Budding


Q.13 State the methods used for growing rose plants.

(i) Stem cutting

(ii) Bud grafting


Q.14 Differentiate between asexual and sexual reproduction.


Q.15 What is vegetative propagation?

It is an asexual method of reproduction.  In this process, a vegetative part of the body like root, stem, and leaves are used for growing new plants is known as vegetative propagation. This property of vegetative propagation is used in methods such as layering or grafting to grow many plants.


Q.16 What methods will you use for growing jasmine and rose plant?

Layering method of artificial vegetative propagation can be used for growing jasmine plant. Stem cutting method can be used for growing rose plant.


Q.17 Give four advantages of vegetative propagation.

(i)  Vegetative propagation is a cheaper and can be easily employed to reproduce plants especially fruit plants.

(ii)New plants produced by vegetative propagation maintain the desirable character of the parent. These plants are genetically identical.

(iii) Plants raised by vegetative propagation can bear flowers and fruits earlier than those produced from seeds.

(iv) Certain plants like banana, grapes, pineapple, rose etc do not form seeds. Thus, this is the only method of reproduction and continuation of species.


Q.18 Name the filamentous structure seen in pond. Explain how they reproduce.

Spirogyra has filamentous structure. They reproduce by the process of fragmentation in which they break up into smaller pieces upon maturation. These pieces grow into new individuals.


Q.19 How does Hydra reproduce? Name another organism that reproduces by a similar method.

Hydra reproduces by budding. Another organism that reproduces through budding is yeast.


Q.20 What is a spore? Name two plants which reproduce through spores.

Spores are special cells formed within special structures called sporangia that disseminate and can form an entire plant under favourable conditions.

Mushroom and fern are reproduced by spores.


Q.21 What will happen when:

(a) A mature Spirogyra filament attains considerable length?

(b) Planaria gets cut into two pieces?

(a) When a mature Spirogyra filament attains considerable length it breaks up into smaller pieces (fragments). These fragments grow into new individuals.

(b) If Planaria gets cut into two pieces, both pieces grow into separate individuals.


Q.22 (a) Is Regeneration the same as Reproduction.Justify

(b) State the mode of asexual reproduction in Plasmodium

(a) Regeneration is not the same as reproduction because most organisms would not normally depend on being cut up to be able to reproduce.

(b) Plasmodium reproduces through multiple fission.


Q.23 Describe regeneration.

Ability of an organism to develop its damaged or lost body parts is called regeneration. For example, simple animals like Hydra and Planaria. It is also a method of asexual reproduction. If Hydra is cut into 2 or more pieces, each body piece grows into a new and complete Hydra. This is known as regeneration.


Q.24 Illustrate with the help of a diagram the spore formation in Rhizopus.

Spore formation in Rhizopus:

This is an asexual method of reproduction in bacteria and fungi. One of the cells enlarges and forms the sporangium (literally meaning spore sac). The nucleus divides many times and then the daughter nuclei are surrounded with protoplasm bits to form daughter cells called spores.

Rhizopus has thread-like hyphae on which tiny ‘blob-on-a-stick’ structures known as sporangia are developed. Sporangia contain spores that are involved in reproduction. The spores are covered by thick walls called the cyst that protect them against drying up. On maturation, the sporangium bursts and releases the spores. Spores survive in adverse conditions like high temperature, scarcity of water and lack of food.

The spores give rise to new organisms under favourable conditions.


Q.25 Why Rhizopus is called as Bread mould and Black mould?

Rhizopus is the most common type of fungus growing on bread as a mass of filaments. Therefore, it is called as bread mould. At maturity, the sporangia appear in black colour during asexual reproduction. Hence it is also called as Black mould.


Q.26 Which type of fission is shown by Plasmodium? Describe briefly.

Plasmodium shows multiple fission. This is an asexual method of reproduction in organisms. In multiple fission, the nucleus divides several times inside the cell itself, producing many daughter nuclei. Once that happens, each of the nuclei that are formed gets enclosed by cytoplasm. This results in separate and individual units. Newly born cells come out of the parent cell after breaking the wall and start living as a new organism.


Q.27 Define grafting. Suggest any two advantages and disadvantages of grafting.

Grafting is a process in which the two parts of different plants are joined by bandaging them tightly.

Advantages:

(i) A young scion can be made to flower when it is grafted on a mature tree.

(ii) Different varieties can be grafted on the same stock.

Disadvantages:

(i) Sexual reproduction is a necessity for evolution.

(ii) Plants produce very few seeds


Q.28 The organisms formed by asexual reproduction are considered as clones. Why? State the advantage of sexual reproduction over asexual reproduction.

In asexual reproduction, the young ones formed are genetically identical to the parents and are considered as clones.

Sexual reproduction has following advantages:

(i) The offspring’s produced by sexual reproduction exhibit diversity of characters because fusing gametes come from two different and sexually distinct individuals.

(ii) Sexual reproduction involves meiosis which provides opportunities for new combination of genes.

(iii) It plays a prominent role in the origin of new species and lead to variation required for evolution.


Q.29 Why is vegetative propagation the only method of reproduction for some plants?

Some plants are propagated only by vegetative propagation because they have lost the capacity to produce seeds .ex Banana, orange, Jasmine etc. Thus, this is the only method of reproduction and continuation of species.


Q.30 What is binary fission? Draw a diagram to show binary fission in  Amoeba.Give examples any 2 organisms that reproduce by binary fission

In binary fission, two single celled organisms are produced through mitotic division.  In this process, the nucleus and cytoplasm are divided as well, which results in two single celled organisms that are identical to the parent cells. Examples of some organisms that reproduce by using binary fission are Amoeba, paramecium, etc.


Q.31 Name the type of asexual reproduction in :

(a) Planaria

(b) Rhizopus

(c) Spirogyra

(d)Hydra

(a)Planaria – Regeneration.

(b)Rhizopus– Spore formation.

(c)Spirogyra– Fragmentation

(d)Hydra– Budding


Q.32 How does natural vegetative propagation occur?

Natural vegetative propagation occurs from modified stems, roots, leaves and bulbs.

Modified stems, onion bears bulbs which when grown in soil develop into a new plant.

Runners- Stems of grass, strawberries etc have nodes and internodes. From nodes develop roots forming a new plant.

Rhizomes of ginger is a horizontal underground stem. If kept in soil with adequate moisture develops into a new plant.

Tuber of potato bears eyes(buds), if sown(entire or in pieces) in soil develops into new plants.

Modified root tubers of sweet potato also grow into a new plant.

Buds produced in the notches along the leaf margins of Bryophyllum fall on the soil and develops into a new plant.


Q.33 How does the process of budding differ from the process of spore formation?

In budding, a protuberance develops on the mature organism's body, attains full maturity and then detaches. While in spore formation, spores are formed within special structures called sporangia that disseminate and can form the entire plant.


Q.34 What is fragmentation? Name a multicellular organism which reproduces by this method

Some multicellular organisms with relatively simple body organisation reproduce by breaking their bodies into small pieces. Each of these pieces is called a fragment. These fragments grow into new individuals and the mode of reproduction is called fragmentation. Spirogyra reproduces by fragmentation.


Q.35 Leaves of Bryophyllum fallen on the ground produce new plants whereas the leaves of Jasmine do not, why?

In Bryophyllum, vegetative propagation occurs through leaves. Buds occur in notches of Bryophyllum leaf. However, when the leaf falls down and comes in contact with the soil, the buds spout and produce plantlets. Leaves of rose do not contain buds and cannot give rise to plantlets.


Q.36 Why do multicellular organisms, need to use more complex ways of reproduction?

All multicellular organisms cannot simply divide cell-by-cell. The reason is that many multicellular organisms, as we have seen, are not simply a random collection of cells. Specialised cells are organised as tissues and tissues are organised into organs, which then have to be placed at definite positions in the body. In such a carefully organised situation, cell-by-cell division would be impractical. Multicellular organisms, therefore, need to use more complex ways of reproduction.


Q.37 What are the advantages of tissue culture?

(i) Rapid multiplication of plants.

(ii)Production of disease free plants.

(iii)Plants can be grown even from sterile hybrids.

(iv) Continuous propagation


Q.38 Name various types of asexual reproduction.

Fission, budding, fragmentation, spore formation, regeneration, parthenogenesis, tissue culture, etc. are different types of asexual reproduction.


Q.39 Define tissue culture?

Tissue culture is the technique of growing cells or tissues in an artificial medium under controlled conditions in the laboratory. 

In tissue culture, new plants are grown by removing tissue or separating cells from the growing tip of a plant. The cells are then placed in an artificial medium where they divide rapidly to form a small group of cells or callus. The callus is transferred to another medium containing hormones for growth and differentiation. The plantlets are then placed in the soil so that they can grow into mature plants.


Q.40 How are the modes of reproduction different in unicellular and multicellular organisms?

Unicellular organisms contain only one cell and can multiply easily by simple cell division, so they reproduce by asexual reproduction. Example: budding, fission, spore formation are some of the asexual methods.

Multicellular organisms which have complex body designs (have organ systems) and reproduce mainly by sexual reproduction.

Example:Humans, animals, plants reproduce sexually.


Q.41 How is the method of asexual reproduction in Leishmania different from that of Amoeba? 

Leishmania reproduces asexually by binary fission that occurs along a definite orientation, i.e., along the length of the cell, while in Amoeba in occurs along any plane.

 

Sexual Reproduction 

Q.42 Mention the reproductive parts of a flower?

The reproductive parts of a flower are stamens and carpel.


Q.43 How does sexual reproduction takes place in plants?

Sexual reproduction in plants takes place in the following steps:

(i) The male reproductive organ namely ‘stamen’ makes the male gametes.

(ii) The female reproductive organ namely ‘carpel’ makes the female gametes.

(iii) The male gametes fertilise the female gametes.

(iv) The fertilised ovules grow and become seeds.

(v) The seeds produce new plants under favourable conditions like presence of water, warmth, air, light etc.


Q.44 What is the difference between unisexual flowers and bisexual flowers?

Bisexual flowers or perfect flowers have both male and female reproductive parts namely stamen and carpel respectively. For example, mustard, Hibiscus and rose

Unisexual flowers contain only one of the two reproductive parts. For example, cucumber, maize and watermelon.


Q.45 Why is sepals and petals called accessory structures of a flower?

Sepals and petals are non- essential or accessory part of the flower because they don’t involve in reproduction.


Q.46 Why is stamen and carpel called as the essential part of a flower?

Stamen and carpel are considered as the essential part of the flower because they are involves in reproduction. Stamen and carpel produce the male and female gametes which give rise to new plants.


Q.47 Name the 4 whorls in a flower and their functions?

There are four whorls in the flower. They are

(i) Sepals-They are collectively called as calyx.They are green in color.

Function-They protect the inner whorls like androecium and gynoecium.

(ii) Petal-They are collectively called as corolla.

Function- Petals help in attracting the insects for pollination.

(iii) Stamen-It is the male part of the flower. It consists of filament, anther and pollen

(iv) Carpel ( pistil)- Carpel is present in the centre of a flower and is the female reproductive part. It is made of three parts namely ovary, style and stigma. The swollen bottom part is the ovary, middle elongated part is the style and the terminal part which may be sticky is the stigma. The ovary contains ovules and each ovule has an egg cell.


Q.48 Define pollination:

Pollination is the transfer of pollen grains from opened anther to the receptive stigma of the carpel.


Q.49 What is the difference between self pollination and cross pollination?


Q.50 What do you know about the post fertilisation stages in plants?

Post-fertilisation changes

(i) After fertilisation the sepals, petals, stamens, style and stigma wither away and usually fall off. In some cases, the sepals may persist in a shrivelled form as in tomato and peas, or become fleshy as in brinjal. The ovary enlarges considerably.

(ii) Inside the ovule, the zygote undergoes cell division to form the embryo and ovule develops into seed. Embryo is the future plant. During seed germination under appropriate conditions, the embryo develops into a seedling and finally the complete plant.

(iii) The ovary wall develops into the fruit wall and the whole ovary after fertilisation is called the fruit.


Q.51 What are the agents of pollination?

The agents of pollination are wind, water and animals especially insects.


Q.52 Define fertilisation?

The process of fusion of two haploid gametes, usually a male and a female gamete leading to the formation of diploid zygote is known as fertilisation


Q.53 What is syngamy?

One male nucleus fuses with the female gamete or egg. This process of fusion of male and female nuclei is called syngamy.


Q.54 Out of the two modes of reproduction, which one of the two confers new characteristics on the offsprings and how?

Only sexual reproduction confers new characteristics on the offspring because the process of DNA replication occurs in sexual reproduction. Mutations occur during DNA replication which give rise to variation, thus confers new characteristics on the offspring.


Q.55 Why cannot fertilisation take place in flowers if pollination does not occur?

Pollination is essential for transfer of pollen grain to stigma. In the absence of pollination, there will be no male gamete (pollen grain) for fertilisation. Hence, fertilisation cannot take place in flowers if pollination does not occur.


Q.56 What do you know about the process of fertilisation?

Fertilisation :

After the pollen grains are deposited on the stigma, the pollen grains absorb water and sugar from the surface of stigma and swell up. The pollen grain produces a fine tube called pollen tube. Eventually, it travels down the whole length of the style into the ovary.

The pollen tube carrying the two male gametes enters the ovule and embryo sac through the micropyle and its tip dissolves. The two male gametes are liberated inside the embryo sac.

One male gamete fuses with the egg to form zygote which grows into an embryo and finally into a new plant. The other male gamete fuses with the secondary nucleus (two polar nuclei) to form the endosperm, which provides nourishment to the growing embryo. The fusion of the male gamete with the female gamete is called syngamy.


Q.57 Differentiate between pollen grain and ovule


Q.58 What happens to different parts of the carpel’s of a flower after fertilization?

Ovary grows and forms the fruit. Style and stigma wither off.


Q.59 Differentiate between fertilisation and germination


Q.60 (i) State the function of (a) stigma (b) pollen tube.

(ii) What happens to the ovule after fertilization ?

(i) (a) Stigma receives pollens.

(b) Pollen tube helps to carry the male germ cell to the female germ cell from the stigma to the ovary.

(ii) After fertilization, the ovule develops into seed.


Q.61 Name the organs that make up the male reproductive system in humans?

Male reproductive system in human consists of the following organs —

(i) Testes in the scrotum

(ii) Epididymis

(iii) Vas deferens

(iv) Urethra

(v) Penis

(vi) Accessory glands (seminal vesicle and prostrate gland)


Q.62 Name the organs that make up the female reproductive system in humans?

Female reproductive system in humans consists of the following organs —

(i) Ovaries

(ii)Fallopian tubes or oviducts

(iii)Uterus or womb

(iv) Vagina


Q.63 What are gonads? What are its functions?

The reproductive organs in animals are called gonads

The gonads control and regulate three major functions:

(a) Produce the gametes as well as the sex hormones (testosterone is produced by the testicles and estrogen and progesterone by the ovaries).

(b) They help in the functioning of the accessory sex organs (i.e., organs which are part of the reproductive system but do not directly produce gametes).

(c) They help in the development of secondary sex characters like breast development in girls and growth of facial hair in boys.


Q.64 What is puberty? When does puberty occur in human male and female?

Puberty is the age or period during adolescence, when the reproductive organs of a child start functioning and the child attains sexual maturity.

In males, puberty is attained at the age of 13-14 years, while in females, it is 10-12 years.


Q.65 What is the normal reproductive life in human female?

The period between menarche and menopause (12 to 50 years) is the normal reproductive life in human female.


Q.66 What are the secondary sex characters in human male?

Secondary sex characters in human males are deepening of voice, growth of beard, moustache and pubic hair.


Q.67 With the help of a diagram, describe how fertilisation takes place in female reproductive system.

During copulation (mating or coitus), the sperms are released in the vagina near the lower end of the uterus. The sperms actively swim with the help of their tails and pass into the uterus.

From the uterus, they reach the oviduct. If there is an egg in the oviduct, it gets fertilised by the sperm.


Q.68 Why do testes lie outside the abdominal cavity?

Testes are present inside a fibrous covering called scrotum or scrotal sac. The scrotum helps in maintaining 1–3°C lower than the body temperature. This is necessary for the development of sperms.


Q.69 Why does menstruation occur?

At the time of ovulation, cycle of events takes place in the uterus and vagina.

(i) In case, fertilisation occurs, the inner wall of uterus thickens to receive the developing zygote. 

(ii) In case, fertilisation does not take place, the thickened wall along with the blood vessels breaks down and moves out of the vagina in the form of discharge called menstrual flow which lasts for 4-5 days.

The cycle of events taking place in the ovaries and uterus every twenty-eight days and marked by menstrual flow, is menstrual cycle


Q.70 Where is an embryo sac found?

Embryo sac is present within the ovule and after fertilisation, it forms the embryo(radical and plumule) and cotyledons of the seeds.


Q.71 Where do the following functions occur? What is the average duration of human pregnancy?

(i) Production of an egg

(ii) Fertilisation

(iii)Implantation of zygote

(i) Ovary

(ii) Fallopian tube

(iii) Uterus

(b) The average duration of human pregnancy is 280 days or 40 weeks.


Q.72 Define implantation?

The embedding of a fertilised mammalian egg into the wall of the uterus (womb) where it will continue developing, is called implantation


Q.73 Name any two mechanical barriers of pregnancy. What are the benefits of using mechanical barriers during sexual act?

Mechanical barriers of pregnancy:

(i) Condoms (ii) Diaphragms 

Benefits of using mechanical barriers

(i) Prevention of pregnancy — Mechanical barriers prevent the passage of sperms into the genital tract of the female. Consequently, pregnancy does not occur.

(ii) No transmission of infections — Mechanical barriers also prevent the transmission of Sexually Transmitted Diseases (STDs) from infected partner to the non-infected partner.


Q.74 What are the functions of ovary and testes?

Ovaries in females and testes in males represent the main reproductive organs. These organs perform two basic functions

  • To produce female gametes (ova) and male gametes (sperms) respectively
  • To secrete sex hormones — testosterone (male hormone from testis) and estrogen (female hormone from ovary)

Q.75 (a) How do the oral pills function as contraceptives?

(b) The use of these pills may be harmful. Why?

(a) Oral pills acts by changing the hormonal balance of the body so that eggs are not released and fertilisation cannot occur.

(b) Since oral pills change hormonal balances, they can cause side effect too.


Q.76 What is gestation?

The period of development of foetus in the uterus till birth is called gestation. It is of 9months duration (i.e., 280 days or 40 weeks from the first day of the last menstrual cycle) in human beings.


Q.77 Write the functions of testoterone secreted from the teste?.

(i) It regulates the formation of sperms,

(ii) Testosterone brings about changes in appearance seen in boys at the time of puberty.

(iii) It develops the accessory sex organs, such as penis, scrotal sacs, epididymis, prostate glands etc.

(iv) It also accelerates protein metabolism causing growth of bones and muscles etc.


Q.78 List and describe in brief any three ways devised to avoid pregnancy?

(i) Foam tablets, jellies, creams and spermicides are common chemicals used by females. These are placed in vagina.

(ii) Ovulation and fertilisation can be prevented by changing hormonal balance of the body. It can be done by taking oral pills.

(iii) Intrauterine Contraceptive Device (IUCD) such as the loop or the copper-T are placed in the uterus to prevent pregnancy. The drawbacks with these devices are bleeding and discomfort. 


Q.79 What are sexually transmitted diseases? Name four such diseases. Which one of them damages the immune system of human body?

The diseases which are spread by sexual contact from an infected person to a healthy person are called sexually transmitted diseases or STDs.

(i) AIDS (Acquired Immuno Deficiency Syndrome)

(ii) Gonorrhoea

(iii)Syphilis

(iv) Genital herpes

‘AIDS’ — damages the immune system of human body.


Q.80 Why is the number of sperms produced always much more than the number of eggs?

Sperms are produced much more in number than eggs because-

(i) Eggs are non-motile whereas sperms are motile and they may be misdirected while they are travelling towards the eggs.

(ii) Sperms are not be able to survive the external environmental conditions for long.

(iii) To increase the probability of fertilisation of eggs.


Q.81 What are the factors responsible for the sharp increase in population?

Factors responsible for population explosions are:

(i) Sufficient availability of food.

(ii) Better nutrition.

(iii)Better health care.

(iv) Reduction in mortality rate due to better medical facilities and health care.

(v) More children reaching the reproductive age


Q.82 State in brief functions of the following parts of the human female reproductive system.

(i) Ovary

(ii) Fallopian Tube

(iii) Uterus?

(i)Ovary— Ovary produces ova or eggs. Ovary also secrete a hormone estrogen which helps in the development of secondary sexual characters like breast development.

(ii)Fallopian tube —Fallopian tube conveys the egg from the ovary to the uterus and provides the appropriate environment for its fertilisation.

(iii)Uterus —After fertilisation, the embryo develops in uterus


Q.83 State in brief the functions of the following parts of the human male reproductive system :

(i) Scrotum

(ii) Testes

(iii)Vas deferens?

(i) Scrotum: It contains and supports the testes. It is situated outside the body cavity and allows the sperm to develop at the optimum temperature, which is slightly lower than body temperature

(ii) Testes: The formation of male germ cells or sperms takes place in it. Leydig cells of testes secrete hormone testosterone which brings about changes in appearance seen in boys at the time of puberty.

(iii)Vas deferens: It ascends into the abdomen, passes over the urinary bladder and receives duct from the seminal vesicles behind the urinary bladder to form the ejaculatory duct.


Q.84 Give 2 reasons for avoiding frequent pregnancies by women:

Frequent pregnancies by women are to be avoided for the following reasons-

(i) It has adverse effect on the health of women

(ii) It increases the rate of population of our country.


Q.85 Draw a neat diagram of the reproductive system of a human female and label it?

 

Value Based Questions :-

Q.1 We hear and read about female foeticide, which is really is a wrong practice. In some families, be it rural or urban, females are tortured for giving birth to a girl child. They do not seem to understand the scientific reason behind the birth of a boy or a girl.

In your opinion, the approach of the society towards mother in this regard is correct or not? Explain the scientific reason.

Prenatal sex determination has been prohibited by law, state two reasons.

State the reason behind the use contraceptive methods is related to the prosperity of a family?

(1a)The approach of the society towards mother in this regard is totally wrong because both men and women have sex chromosomes.  Men usually have one X and one Y chromosome, while women have two X's.

When an egg or sperm is made, it only gets one of the sex chromosomes from the parent. This means that women can only make eggs with an X chromosome.  But men can make either X or Y sperm.

During fertilization, the sperm cells race toward the mother-to-be's egg cell.  If a sperm with a Y beats all others, then the foetus will be XY. The pregnancy will result in a boy.

However, if a sperm with an X wins the race to the egg, then the foetus will be XX.  The parents will have a baby girl.

Prenatal sex determination has been prohibited by law because of indiscriminate female foeticide. As a result of this, child sex ratio is declining at an alarming rate in some sections of our society. For a healthy society, the female-male sex ratio must be maintained.

Use contraceptive methods is related to the prosperity of a family in the following ways-

Slower population growth allows families and communities to invest more in providing quality education and health care and to improve infrastructure. Children who are healthy and educated are primed to become productive adults who can help to fuel the economy.

When women are able to plan and space their pregnancies, they can invest more in each family member. And women who have fewer children have more time to earn wages outside the home, which boosts family income and quality of life and reduces poverty.


Q.2 Ram and Rahim are students of Class-IX. Both were initially good in studies. After some time academic performance of Rahim started declining and he became irritable. This change was noticed by his class teacher the teacher, while interacting with Rahim found out that he had six siblings and whole family lived in a single room. Mother was not able to devote much attention to him and resources were not sufficient.

(i) After going through the situation, what are the factors, which you think, are responsible for change in behaviour and his poor performance in studies

(ii) Which permanent contraceptive method can Rahim’s father adopt?

iii) Mention two factors that determine the size of population

(i) The factors responsible for the change in behaviour and poor performance of Rahim were –

As Rahim’s parents are forced to support a large family, they are not able to invest more in providing quality education and health care to each and every child. Moreover, lack of proper food, adequate space and attention by his parents has worsened the condition of Rahim.

(ii) Sterilization is considered a permanent method ofbirth controlthat a man or woman chooses. Here, Rahim’s father can go for In vasectomy, the vas deference is blocked and sperm transfer is prevented.

The 2 factors that determine the size of the population are-

- Birth rate(rate of birth)

- Death rate(rate of death)



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