CBSE Class 10 Science How do humans reproduce Sure Shot Questions A

CBSE Class 10 Science Chapter 8 How Do Organisms Reproduce MCQs

Question. Which of the following plants possess unisexual flowers?
(a) Watermelon
(b) Hibiscus
(c) Mustard
(d) Both (b) and (c)
Answer. A

Question. Which of the following is celebrated as “World AIDS Day”?
(a) September 1
(b) October 1
(c) November 1
(d) December 1
Answer. D

Question. Which of the following is the correct sequence regarding sexual reproduction in a flowering plant?
(a) Pollination, fertilisation, seedling, embryo
(b) Seedling, embryo, fertilisation, pollination
(c) Pollination, fertilisation, embryo, seedling
(d) Embryo, seedling, pollination, fertilisation
Answer. C

Question. Which of the following organisms does not depend on reproduction to exchange genetic material?
(a) Lion
(b) Papaya
(c) Bacterium
(d) Cockroach
Answer. C

Question. ––––––– is the portion on which grafting is done and it provides the roots.
(a) Stock
(b) Scion
(c) Bud
(d) None of these
Answer. A

Question. External fertilisation takes place in
(a) fish and frog
(b) frog and monkey
(c) dog and goat
(d) goat and fish.
Answer. A

Question. Match the columns and select the correct option from the given codes.
Column I                    Column II
A. Parturition         (i) The act of expulsion of
                                 fully grown foetus from
                                 mother’s uterus
B. Menopause     (ii) Release of one ovum from
                                one of the ovaries every
                                month
C. Gestation        (iii) Phase during which
                                 menstruation ceases
D. Ovulation        (iv) Complete development of
                                 the fetus inside the womb
(a) A - (iv), B - (ii), C - (i), D - (iii)
(b) A - (i), B - (iii), C - (iv), D - (ii)
(c) A - (iv), B - (iii), C - (i), D - (ii)
(d) A - (i), B - (ii), C - (iv), D - (iii)
Answer. B

Question. Tissue culture technique is used for
(a) growing disease free plant
(b) rapid multiplication of plant
(c) multiplication of sterile plants
(d) all of these.
Answer. D

Question. Human seminal plasma, the fluid part of semen, is produced by contributions from which of the given part?
A. Prostate gland
B. Bulbourethral gland
C. Urethra
D. Seminal vesicles
(a) A and D only
(b) A only
(c) A, B, C and D
(d) A, B and D only
Answer. D

Question. Examples of vegetatively reproducing plants are
(a) tomato, okra, onion, cauliflower
(b) potato, ginger, onion, sugarcane
(c) cauliflower, onion, potato, tomato
(d) okra, onion, ginger, sugarcane.
Answer. B

CBSE Class 10 Science Chapter 8 How Do Organisms Reproduce Case Based MCQs

Case I : Read the following passage and answer questions.

P and Q are two monoecious plants. P bears bisexual flowers whereas Q bears unisexual flowers. P does not need a pollinating agent whereas pollinating agent is required in case of Q.

Question. Select the option that correctly identifies plant P and Q.
(a) P - Papaya, Q - Marigold
(b) P - Pea, Q - Cucurbit
(c) P - Sunflower, Q - Orchid
(d) P - Tulip, Q - Daffodil
Answer. B

Question. Select the correct option regarding plants P and Q.
(a) Seed setting is assured in plant P even if all its flowers are emasculated.
(b) Male flowers of plant Q always open only after the female flowers of the plant are pollinated.
(c) Female flowers of plant Q can reproduce by cross pollens or self pollens depending upon the genus to which plant Q belongs to.
(d) P is a cross pollinated plant whereas Q is a self pollinated plant.
Answer. C

Question. How can self pollination be avoided in plant P?
(a) By removing all the flowers of plant P
(b) By removing all the anthers of all the flowers
(c) By removing all the carpels of all the flowers
(d) None of these
Answer. B

Question. Which of the following holds true for plant Q?
(a) Plant Q bears complete flowers.
(b) Plant Q bears either male flowers or female flowers but never both.
(c) Sexual reproduction in plant Q may or may not give rise to genetic variations.
(d) All of these
Answer. C

Question. Select the correct statement.
(a) Flowers of plant P produce large number of pollen grains as compared to flowers of plant Q.
(b) Sexual reproduction in plant P does not bring variations.
(c) Sexual reproduction in plant P often gives rise to new varieties due to accumulation of genetic variations.
(d) Both (a) and (b)
Answer. B

Case II : Read the following passage and answer questions.

X, Y and Z are three sexually transmitted diseases (STDs). X and Z are caused by bacteria whereas Y is caused by virus P. Virus P lowers the immunity of a person and leads to an incurable disease. X starts as painless sores on genitals rectum or mouth. Z causes painful urination and abnormal discharge from genitals.

Question. Select the option that correctly identifies disease X, Y and Z?
      X Y Z
(a) AIDS Syphilis Gonorrhoea
(b) Syphilis AIDS Gonorrhoea
(c) Gonorrhoea Syphilis AIDS
(d) Syphilis Gonorrhoea AIDS
Answer. B

Question. Identify virus P from the given paragraph.
(a) Human papilloma virus
(b) Human adenovirus
(c) Human immunodeficiency virus
(d) Human cytomegalovirus
Answer. C

Question. What are the symptoms of disease Y?
(a) Weight loss
(b) Fever or night sweats
(c) Fatigue and weakness infections
(d) All of these
Answer. D

Question. Select the incorrect statement regarding diseases X and Y.
(a) Both X and Y can spread from infected mother to unborn baby during pregnancy.
(b) Both X and Y can spread from infected partner to healthy partner by unprotected sex.
(c) Y can also spread through use of contaminated needles and blood transfusion.
(d) None of these
Answer. D

Question. How can disease Y be prevented?
(a) By following polygamy and having protected sex.
(b) Use of sterilised needles for injecting medicines, blood tests, etc.
(c) Collecting blood from unknown donors without background check by blood bank professionals.
(d) All of these
Answer. B

CBSE Class 10 Science Chapter 8 How Do Organisms Reproduce Short Answer Type Questions 

Question. Some flowers of pumpkin and bottle gourd develop fruits whereas other flowers fail to develop fruits. What may be the possible reason?
Answer. Pumpkin and bottle gourd bear unisexual flowers. Some flowers are male and others are female. Male flowers do not develop fruits. They produce pollen grains. The female flowers posses carpels which develop fruits after fertilisation.Therefore, only female flowers develop fruits but not the males.

Question. Give reasons for the following :
(i) Oral pills help in birth control.
(ii) Petals of flowers are variously coloured.
Answer. (i) Oral pills contain the hormone estrogen and progesterone which check ovulation.
(ii) The petals of the flowers are coloured to attract pollinators for cross pollination.

Question. How population growth can be prevented?
Answer. Population growth can be prevented by family planning programmes which involve various types of birth control measures like mechanical, chemical, surgical and natural methods.

Question. State two differences between budding in Hydra and budding in yeast.
Answer. Differences between budding in Hydra and budding in yeast are as follows:

Question. Do you think sex-education is necessary in schools?
Answer. A correct knowledge about reproductive organs, adolescence related changes, sexually transmitted diseases, etc., will save the young minds from myths and
misconceptions about sex related aspects and help them to lead a reproductively healthy life. Thus, sex-education is necessary in schools.

Question. Pollination brings male gamete in close proximity to the female reproductive part. Justify the statement.
Answer. Pollination is the process of transfer of pollen grains from the anther of a flower to the stigma of the same or another flower. Pollen grains bear male gametes which are carried to the ovary of a flower with the help of pollen tubes. Hence, pollination brings male gametes in close proximity to the female reproductive part.

CBSE Class 10 Science Chapter 8 How Do Organisms Reproduce Short Answer Type Questions

Question. Write a short note on tissue culture.
Answer. Tissue culture is a modern technique of vegetative propagation in which tissues from the growing tip of a plant are removed and placed in an artificial medium where they divide rapidly to form a small group of cells or callus which is again 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. This technique is commonly used for ornamental plants.

Question. Why does the body show sexual maturation at puberty?
Answer. There is a need for specialised cell types in multicellular bodies to carry out specialised functions. The creation of germ-cells to participate in sexual reproduction is another specialised function. Human beings also develop special tissues for reproduction. However, while the body of the individual organism is growing to its adult size, the resources of the body are mainly directed at achieving this growth and the maturation of the reproductive tissue is not likely to be a major priority. So, during puberty maturation of reproductive tissues takes place to attain sexual maturity and the rate of general body growth slows down.

Question. Describe the structure of human male reproductive system. Write down the role of each part.
Answer. Human male reproductive system consists of testes, scrotum, vas deferens, urethra and penis.
(a) Testes : The human male possesses two testes, which are the primary reproductive organs, lying outside the abdominal cavity. The two testes are the male gonads, which are the sites where male gametes, i.e., sperms are produced. The testes also produce the male sex hormone-testosterone. The testes of man produce sperms from puberty onwards, throughout his life.
(b) Scrotum: The scrotum is a pouch of skin that hangs between the legs. It is divided internally into right and left scrotal sacs by a partition. The two testes lie in respective scrotal sacs. The scrotum acts as a thermoregulator and provides an optimal temperature for the formation of sperms. The sperms develop at a temperature 2 – 2.5°C lower than the normal body temperature.
(c) Vas deferens : This is a straight tube, about 40 cm long, which carries the sperms from epididymis towards the urethra.
(d) Urethra: It is about 20 cm long tube that arises from the urinary bladder to carry urine. It runs through the penis and opens to the outside through male genital pore. The contents of two seminal vesicles, and sperms from vas deferens also join the urethra. Thus urethra carries urine from the bladder, as well as sperms from the vasa deferentia through the penis.
(e) Penis: Penis is a long and thick muscular organ made up of mostly erectile tissue. At the time of sexual act, the erectile tissue gets filled with blood causing the penis to become erect. It is inserted into the vagina of the female where sperms are ejaculated for the purpose of reproduction.

Question. What is the significance of sexual mode of reproduction?
Answer. Sexual reproduction may be defined as the production of offsprings (new individuals) by the fusion of two gametes (usually one from male parent and the other from female parent) to form a diploid zygote which develops into a mature organism. Gamete formation involves meiosis or reduction division. The gamete mother cell is diploid (2n), i.e., it has two sets of chromosomes. This single diploid cell divides by meiosis to form 4 haploid (n) daughter cells. Each daughter cell becomes a gamete, either male or female. Each gamete possesses single set of chromosomes. Thus, this division involves copying of the DNA as well as the cellular apparatus. There is a stage in such nuclear division where crossing over of chromosomes take place. This is very important step which results in a slight different composition of chromosomes in gametes. Fusion of these gametes results in the formation of a slightly different individuals which show variations. The variations which lead to the appearance of such characters which fit to the changing environment result in the survival of the species. Chances of variation, therefore, are much more in sexual mode of reproduction as compared to asexual reproduction. Moreover, chances of
the production of compatible generations are also more in
sexual reproduction.

Question. Answer the following.
(a) Give reasons for avoiding frequent pregnancies by women.
(b) Explain the following methods of contraception giving one example of each.
(i) Barrier method (ii) Chemical method
(iii) Surgical method
Answer. (a) Having pregnancies too frequently and giving child birth at quick succession reduce mother’s health and vitality and cause mental strain. Health of children is also affected due to nutritional deficiencies.
(b) (i) Barrier method: These are physical devices to prevent the entry of sperm into the female genital tract during copulation. They also protect against sexually transmitted diseases, e.g., condoms. Condoms are thin, strong rubber sheaths used by man to cover the erect penis. It is simple but effective and widely used contraceptive that has no side effects. It checks pregnancy by preventing deposition of semen in the vagina.
(ii) Chemical method: Foam tablets, jellies, pastes, creams and spermicides are some common chemicals used by females. These are placed in vagina. These chemicals adhere to the mucous membrane and immobilise and kill the sperms.
(iii) Surgical method: Surgical methods include – vasectomy and tubectomy. Vasectomy is a small surgical operation performed in males. It involves removal of a small portion of the sperm duct (or vas deferens) by surgical operation. The two cut ends are then ligated (tied) with threads. This prevents the sperms from coming out. Tubectomy is done in females where oviducts are cut and the cut ends are tied with threads.

HOW DO ORGANISMS REPRODUCE?

1. Define reproduction.

2. Define fertilization.

3. Where the fertilization does takes place in human female?

4. Name two type of reproduction.

5. What method will you use for growing jasmine and rose plant?

6. Define menstruation.

7. Write the name of male and female reproductive part of a flower.

8. Define gestation period. What is the gestation period in human?

9. Why do testes in mammals descend in scrotum?

10. Name the type of fission carried out by Amoeba.

11. Name two sexually transmitted diseases.

12. What is vegetative propagation?

13. Name the male and female gonads and what are the products they produce.

14. Which part of human female reproduction system is called ―birth canal and the ―womb?

15. Write the full form of IUCD and AIDS,

16. What is syngamy?

17. What is advantage of fruit formation in plant?

18. What is ovulation?

19. What is menopause?

20. What is the importance of the process of reproduction?

21. What is species?

22. Do organisms produce exact copies of themselves during reproduction?

23. What is the importance of variations?

24. Why is variation beneficial to the species but not necessarily for the individuals?

25. What is the importance of DNA copying in reproduction?

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