How do Organisms Reproduce Class 10 Important Questions and Answers
Important Questions for Class 10 Science Chapter 8 How do Organisms Reproduce covers each topic of the chapter. These questions aim at providing a better understanding of the chapter to the students and can be downloaded in PDF format. These important question bank help students in clearing their doubts so that they can score well in the exam.
While preparing for exams, students should practise these important questions of Class 10 Science to understand the concepts better. Solving important questions of Class 10 Science Chapter 8 will teach students time management skills and enhance their problem-solving skills. Also, students may come across a few of these questions in the board exam.
Important Questions for Class 10 Science Chapter 8 – PDF
1. What is meant by budding?
Answer: Budding is one of methods of asexual multiplication in which the cell division takes place at one specific site and turns out into an outgrowth. The little knob like projection turning out from the main body is known as a bud. The new life form grows there at the same site and get detached at when fully grown leaving behind the scar tissue. Since the proliferation is asexual, the recently made life form is a clone and is identical to the parent life form.
For example: budding in yeast
2. In which organisms spore formation takes place?
Answer: The spores are the minute, intense and resistant bodies which are round fit and can develop into another plant under reasonable conditions. The spore formation method of asexual reproduction is used by unicellular as well as multicellular organisms.
For example: Rhizopus, Mucor and some non-flowering plants.
3. What is meant by binary fission?
Answer: Binary fission is a type of asexual reproduction which involves the splitting of parent organism into two new organisms. In this type of asexual reproduction the parent ceases to exist and two new forms come into existence.
For example: Amoeba, Paramecium etc.
4. What is meant by ovulation?
Answer: Ovulation is the arrival of an egg from one of a lady’s ovaries. After the egg is discharged, it goes down the fallopian tube, where fusion by a sperm cell may happen.
5. What is the role of placenta?
Answer: The role of placenta is to provide all the developing requirements to the developing foetus. These requirements are:
- Nutrition
- Respiration
- Excretion etc.
6. What is the function of testes?
Answer: Testes are the primary reproductive structures or organs in males. Its functions are
- To make sex cells i.e. male gametes called sperm.
- To make male sex hormone, testosterone.
7. What is the function of prostate glands and seminal vesicles?
Answer: Prostrate gland is a male reproductive organ which secretes prostrate fluid which is a component of semen. The seminal vesicles secrete a significant proportion of the fluid that ultimately becomes semen. The secretions of seminal vesicle and prostrate gland provides nutrition to sperm and also make their further transport easy.
8. What is the function of ovaries?
Answer: Ovaries are the primary reproductive organs in females. The functions of ovaries are:
- To make mature female sex cells i.e. female gametes called ova.
- To make female sex hormones, oestrogen and progesterone.
9. Why is DNA copying an essential part of the process of reproduction?
Answer: DNA is the carrier of genetic information. It is the blueprint of necessary information. For a parent to produce offspring of its own type, it is essential that the offspring carries same DNA as in parents. Thus, DNA copying or DNA replication is the only way through which a cell makes additional copies of same DNA which can be transmitted to its offspring. Thus, DNA copying is an essential mechanism.
10. What are bisexual organisms? Give examples.
Answer: The organisms which have both male and female reproductive system within the same organism called bisexual organisms.
For example: earthworm, leech, starfish etc.
11. Name those parts of the flower which server the same function as the following do in the animals.
(i) Testis (ii) Ovary (iii) Eggs (iv) Sperms
Answer: (i) Testis: Anthers
(ii) Ovary: ovary
(iii) Eggs: ovules
(iv) Sperms: pollens
12. What is the importance of variation for an organism?
Answer: Variation is defined as the slight difference in two organisms or species which distinguishes one from the other. Individual with variation has higher chances of survival since they are better adapted to the environment. Thus, for survival of the fittest and to continue life on earth, variation is an important phenomenon.
13. What is so peculiar about the binary fission in leishmania?
Answer: Leishmania reproduces by the process of binary fission. It has a greater degree of organisation in its body, having a whip-like structure called flagellum at its one end. In Leishmania, the splitting of parent cell takes place in a definite plane {longitudinally} with respect to flagellum at its end.
14. What is the importance of: (a) Mitosis (b) Meiosis?
Answer: (a) Mitosis:
It is important for:
- Increasing the number of cells in a particular tissue.
- Protection from harmful microorganism in case of a cut or wound.
- Replacing or repairing dead or inefficient cells in a tissue.
- To maintain the ratio of cytoplasm to nucleoplasm as well as surface area to volume.
(b) Meiosis:
- It is the most essential process in all sexually reproducing animals.
- Maintain chromosomal number in zygote.
- Meiosis show crossing over, resulting in genetic recombination.
- Meiosis show a number of incidences of mutation (sudden changes in genetic material).
15. Give the significance of vegetative propagation?
Answer: Significance of vegetative reproduction:
- Plants in which valuable characters of parents must be kept up, are proliferated vegetatively.
- The plants which don’t deliver feasible seeds are proliferated by this method.
- Plants with decreased intensity of sexual multiplication, long lethargic time of seed or poor practicality are duplicated effectively through this method.
- Vegetative propagation likewise helps in expelling regular diseases from the parent plant.
16. What is the difference between fragmentation and regeneration?
Answer:
| Fragmentation | Regeneration |
| Organisms that are fragmented result in each fragment growing into an individual organism | Regeneration occurs when an organism only regrows a lost limb or any other part of the body. |
| A new individual emerges from each fragment | No new organisms are formed |
| Only a few organisms can fragment and form new individuals | All organisms exhibit the ability to regenerate (Only to some degree) |
| Fragmentation is observed in organisms such as flatworms and sponges | Examples of regeneration include regrowing a lost limb, such as the tail of a lizard. (Please note: Most lizards can lose their tails and then have them grow back. But if they lose their forelimb or hindlimb, it will not regrow) |
17. How does binary fission differ from multiple fission?
Answer:
| Binary fission | Multiple fission |
| 2 daughter cells are formed from the splitting of the parent’s cell or Nucleus. | Many daughter cells are formed from the splitting of the parent’s cell or Nucleus. |
| Occurs during favourable conditions. | Occurs during unfavourable conditions. |
| Divides only once. | Divides repeatedly. |
| Both the Nucleus and cytoplasm divide simultaneously. | First, the nucleus divides and is surrounded by cytoplasm. |
| Includes definite pattern of division. | Has no definite pattern of division. |
| Example: Amoeba, Bacteria, Euglena, etc., | Example: Plasmodium, Sporozoans, Algae, etc. |
18. Why does menstruation occur?
Answer: In every ovulation cycle, an egg is discharged from the ovary which is exchanged to the fallopian tube. Also, the uterus sets itself up for a conceivable pregnancy. The lining of uterus thickens. At the point when no conception happens, the covering of the uterus is shed in pieces; alongside the unfertilized egg. These things are discharged out through the vagina through dying; called mensuration. The sole reason for the mensuration to occur is due the change in the levels of female hormones, oestrogen and progesterone.
19. Give two differences between pollination and fertilization.
Answer:
| Pollination | Fertilization |
| Pollination is an external process. | Fertilization is an internal process. |
| Pollination takes place before fertilization. | Fertilization occurs after pollination. |
| Pollination occurs from anthers of stamens to stigma of the ovary | It is the fusion of female and male gametes |
| It is a physical process. | It is a genetic and biochemical process. |
| Pollination agents are wind, water, birds, insects, and other animals. | Fertilization takes place by growing pollen tube which enters the ovule |
| External factors are required. | External factors are not required. |
| This process leads to fertilization. | This process leads to the formation of seeds. |
| The pollen tube is not required | Pollen tubes are formed for transferring male gametes into an egg cell. |
| Pollination occurs only in flowering plants. | Fertilization is followed by almost in every living being present on the planet earth, including plants, animals, birds, insects, humans, etc. |
20. How are modes for reproduction different unicellular and multicellular organisms? How does reproduction help in providing stability to population of species?
Answer: Unicellular life forms dependably replicate by asexual reproduction; like binary fission, fragmentation, regeneration, sporulation etc. Multicellular forms, then again, utilize both asexual and sexual strategies for reproduction. While unicellular living beings normally take after the asexual strategies for propagation; the vast majority of the multicellular life forms take after sexual methods for generation.
Each specie needs to continually struggle for its survival. Characteristic predators and fancies of nature continue expelling a huge segment of the number of inhabitants in a
specific animal types. In addition, the normal cycle of life and passing additionally expels a segment of the populace. Reproduction is an approach to recharge the lost segment of populace. In this manner, one might say that reproduction is connected to the soundness of populace of an animal varieties.
21. What is the vegetative propagation? Where this method of reproduction find its application? List the advantages of vegetative propagation.
Answer: Vegetative propagation is a type of asexual reproduction. In this, new plants are produced by the parts of plants like stem, roots and leaves without the help of any reproductive organ. This technique is widely used in horticultural crop nurseries.
Advantages of vegetative propagation are:
- Plants in which valuable characters of parents must be kept up, are proliferated vegetatively.
- The plants which don’t deliver feasible seeds are proliferated by this method.
- Plants with decreased intensity of sexual multiplication, long lethargic time of seed or poor practicality are duplicated effectively through this method.
- Vegetative propagation likewise helps in expelling regular diseases from the parent plant.
22. What is meant by pollination? What are its two type? What are the agents which help in pollination?
Answer: The transfer of pollen gains from the anther of a stamen to the stigma of a pistil or carpel is called pollination. The pollination is of two types:
Self-pollination: when the pollen gains from the anther of a flower are transferred to the stigma of the same flower or another flower of same plant.
Cross-pollination: when the pollen gains from the anther of a flower are transferred to the stigma of a flower of the other but similar plant.
Agents of pollination are:
- Air
- Water
- Insects
- Bees and moths
- Butterflies and bats
23. Define the term double fertilization in plants. After fertilization name the part in each case which develops into (i) the fruit (ii) the seed.
Answer: Double fertilization is a type fertilization mechanism of flowering plants. This process involves the fusion of a female gametophyte (mega gametophyte also called the embryo sac) with two male gametes (sperm).
- The ovary of flower develops and becomes a fruit.
- The ovule of flower develops and becomes a seed.
24. Distinguish between a gamete and zygote.
Answer: Difference between a gamete and zygote:
| Zygote | Embryo |
| The term zygote is from Greek word “zygotos” which means to “join” | The term embryo is from Latin work “embryum” which means “that which grows” |
| Zygote is unicellular | Embryo is multicellular |
| The process of formation of zygote is known as fertilization | The process of formation of embryo is known as embryogenesis |
| In medical terms, zygote is known as zygocyte | In medical terms, embryo is known as diploid eukaryote |
25. (a) What is a clone? Why do offspring formed by asexual reproduction exhibit remarkable similarity?
(b) What is the basis for evolution? Where is the zygote located in the flower after fertilization?
Answer: (a) A copy of something is known as a clone. During sexual multiplication, the characters in a posterity are attributes of their parents. Because of this, posterity framed after sexual multiplication show momentous similarity.
(b) The zygote located in the ovary in the flower after fertilization.
26. Draw a labelled diagram of L.S. of flower. What is the function of anther?
Answer:
The swollen top of the stamen is called anther which makes the pollen grains and stores them.