Reproduction In Organisms Class 10th Science Gujarat Board Solution

Class 10th Science Gujarat Board Solution
Exercise
  1. Asexual reproduction is:A. a fusion of specialized cells B. a method by which all types of…
  2. One of the following organisms does not reproduce by binary fission. This is:A. Amoeba B.…
  3. Reproduction is essential for living organisms in order to :A. Keep the individual organ…
  4. A multicelluar organism which reproduces by budding is:A. Amoeba B. Yeast C. Paramecium D.…
  5. A simple multicelluar animal having tentacles and lives in freshwater reproduces by the…
  6. In which of the following living organisms spore formation takes place ?A. Mucor B.…
  7. Method of a sexual reproduction in SpirogyraA. Division of a cell into two cells B.…
  8. An alga which reproduces by the asexual reproduction method called fragmentation is :A.…
  9. The cut part of plant stem (having roots and fixed to ground) which is used in the process…
  10. In asexual reproduction, two off springs having the same genetic material and the same…
  11. A. Name two animals which reproduce sexually. B. Name two animals which reproduce…
  12. Name the method by which Paramecium reproduces. Is this method sexual or asexual?…
  13. Name the asexual method of reproduction in yeast.
  14. Name the asexual method of reproduction in (a) Hydra, and (b) Plasmodium.…
  15. Name the artificial propagation of the rose plant for reproduction.…
  16. Which artificial propagation method is used for the production of citrus plants?…
  17. Name two plants which are propagated by layering method.
  18. Name two plants which are propagated by cutting method.
  19. Write down the name of different methods of asexual reproduction.…
  20. a. What is the basic difference between asexual reproduction and sexual; reproduction? b.…
  21. What do you mean by regeneration? Name two animals which can regenerate fully from their…
  22. Explain vegetative propagation with the help of two examples. List two advantages of…
  23. Describe the layering method for the artificial propagation of plants. IIustrate your…
  24. a. What is a tuber? Give example. b. Name one commonly used vegetable which is propagated…
  25. What is meant by vegetative propagation?
  26. Explain how, new Bryophyllum plants can be produced from the leaves of the old plant?…
  27. Name one organism which reproduces by fission and another by fragmentation. Describe these…
  28. What is the meaning of multiple fission : Describe.
  29. Describe the method of reproduction in fungus.

Exercise
Question 1.

Asexual reproduction is:
A. a fusion of specialized cells

B. a method by which all types of organisms reproduce

C. a method producing genetically identical off springs.

D. A method in which more than one parent are involved


Answer:

Asexual reproduction is the process by which genetically identical offsprings are produced from a single parent without gametes formation.


Question 2.

One of the following organisms does not reproduce by binary fission. This is:
A. Amoeba

B. Plasmodium

C. Euglena

D. Paramecium


Answer:

Plasmodium reproduces by multiple fission where a single parent cell divides into several small, equal sized daughter individuals.


Question 3.

Reproduction is essential for living organisms in order to :
A. Keep the individual organ alive

B. fulfil their energy requirements

C. Maintain growth

D. Continue the species for ever


Answer:

Reproduction is essential to continue the species forever generations after generations. It is essential for the survival of a species.


Question 4.

A multicelluar organism which reproduces by budding is:
A. Amoeba

B. Yeast

C. Paramecium

D. Hydra


Answer:

Hydra is a multicellular organism which reproduces by budding process where an outgrowth called bud appears from parent’s body which grows into a new individual and gets separated from parent body.


Question 5.

A simple multicelluar animal having tentacles and lives in freshwater reproduces by the asexual method of:
A. Binary fission

B. Spore formation

C. Budding

D. Fragmentation


Answer:

Hydra is a simple multicellular animal which have tentacles and lives in freshwater which reproduces by budding method, an asexual method of reproduction.


Question 6.

In which of the following living organisms spore formation takes place ?
A. Mucor

B. Planarian

C. Spirogyra

D. Potato


Answer:

Mucor reproduces asexually by spore formation. Spores are usually produced in sporangia. The fungal hypha develops an enlarged sporangium where spores are produced.


Question 7.

Method of a sexual reproduction in Spirogyra
A. Division of a cell into two cells

B. Breaking up of filaments into smaller bits

C. Division of a cell into many cells

D. Formation of a large number of buds


Answer:

In spirogyra, filament breaks into small parts and each part grows into a new spirogyra.


Question 8.

An alga which reproduces by the asexual reproduction method called fragmentation is :
A. Rhizopus

B. Salmonella

C. Plasmodium

D. Spirogyra


Answer:

In spirogyra, filament breaks into small parts and each part grows into a new spirogyra. This process is called fragmentation an asexual method of reproduction.


Question 9.

The cut part of plant stem (having roots and fixed to ground) which is used in the process of grafting is ....
A. stock

B. scion

C. cutting

D. bud


Answer:

The cut part of plant stem which have roots fixed into soil in which grafting is performed is called stock.


Question 10.

In asexual reproduction, two off springs having the same genetic material and the same body features are called:
A. callus

B. twins

C. clones

D. chromosomes


Answer:

Clones are the genetically identical individuals of an organism having same body features and are produced through asexual reproduction either naturally or artificially.


Question 11.

A. Name two animals which reproduce sexually.

B. Name two animals which reproduce asexually.


Answer:

A. Two animals which reproduce sexually are human beings, lion.

They both produce male and female gametes, two parents are involved, male and female gametes unite to form zygote which grows into a full-term baby inside female’s body.


B. Two animals which reproduce asexually are hydra and amoeba.


Only one parent is involved without formation of gametes. Identical offspring’s are produced in case of asexual reproduction.



Question 12.

Name the method by which Paramecium reproduces. Is this method sexual or asexual?


Answer:

Paramecium reproduces by binary fission which is an asexual method of reproduction. The parent cell divides into two small nearly equal sized identical daughter cells which grow into adult organisms.



Question 13.

Name the asexual method of reproduction in yeast.


Answer:

Yeast reproduces by budding asexually. A small outgrowth called bud arises from parent yeast cell during favourable conditions. It gradually enlarge, nucleus enlarges and divides into two. One of the nuclei goes to the bud. Bud grows and become larger equal in size to parent cell. It may separate out from parent cell or form chain of buds.



Question 14.

Name the asexual method of reproduction in (a) Hydra, and (b) Plasmodium.


Answer:

In hydra asexual method of reproduction is budding where an outgrowth called bud appears from parent’s body which grows into a new individual and gets separated from parent body.


In Plasmodium asexual method of reproduction is multiple fission where a single parent cell divides into several small, equal sized daughter individuals.




Question 15.

Name the artificial propagation of the rose plant for reproduction.


Answer:

Cutting method is used in case of rose plant for reproduction where a small cutting of stem containing buds is planted on wet soil which will develops roots after few days and grows into a new plant. It is an artificial method of propagation.



Question 16.

Which artificial propagation method is used for the production of citrus plants?


Answer:

Layering method is employed for production of citrus plants like lemon. In this method a part of stem is pulled towards ground and covered with soil, from which roots will develop after few days and it will grow into a new plant by detaching from parent plant.



Question 17.

Name two plants which are propagated by layering method.


Answer:

Layering is defined as the process in which a part of stem is pulled towards the ground and covered with soil. This leads to growth of roots from the covered part and at that time it is removed from the parent plant and grows independently. Two plants which propagated by layering method are chrysanthemum and lemon.



Question 18.

Name two plants which are propagated by cutting method.


Answer:

Cutting of parts of plant such as stem, shoot or leaf which bore some buds are taken and lower part is buried in moist thus resulting in growth of roots and some days a whole plant. Two plants which propagated by cutting method are rose, bougainvillea.



Question 19.

Write down the name of different methods of asexual reproduction.


Answer:

Different methods of asexual method of reproduction are fission, budding, fragmentation, regeneration, spore formation, vegetative propagation etc.



Question 20.

a. What is the basic difference between asexual reproduction and sexual; reproduction?

b. Which of the following organisms reproduce by sexual method and which by asexual method? Amoeba, Cats, Humans, Birds


Answer:

a.



b. Amoeba reproduces by asexual method i.e. by binary fission.


Cats, human beings, birds reproduce sexually.



Question 21.

What do you mean by regeneration? Name two animals which can regenerate fully from their cut body parts.


Answer:

Regeneration is the ability of an organism to regenerate its lost parts of the body. Hydra and Planaria can regenerate fully from their cut body parts.

Regeneration is the process by which an organism has an ability to regenerate its lost parts of the body which might have been removed by injury or by some other methods. When Planaria or hydra is cut into many pieces, each piece grows into a complete organism. Regeneration is carried out by specialized cells which have the capacity to develop, proliferate and differentiate into various cell types and tissues.




Question 22.

Explain vegetative propagation with the help of two examples. List two advantages of vegetative propagation.


Answer:

The growth of new plants from vegetative parts of the plant like roots, stem, leaves other than the seeds is called vegetative propagation.

a. Cutting: Small piece of plant part like roots, stem or leaves is cut and is used for propagation. Examples: Rose, china-rose, sugarcane etc.


b. Layering: It is the process where roots are induced when a stem comes in contact with the ground. In this method a part of stem is pulled towards ground and covered with soil, from which roots will develop after few days and it will grow into a new plant by detaching from parent plant.


Examples: Grapevine, jasmine, litchi, mango, lemon etc.


Two advantages of vegetative propagation are-


a. It is cheaper, easier and rapid method.


b. The plants which cannot produce seeds also can be easily propagated by this method.


c. The plants produced by this method bear fruits and flowers earlier.


d. It produces new individuals with exactly identical qualities as the parent, which preserves the parental characteristics.



Question 23.

Describe the layering method for the artificial propagation of plants. IIustrate your answer with the help of labelled diagram. Name any two plants which are propagated by the layering method.


Answer:

It is the process where roots are induced when a stem comes in contact with the ground. In this method a part of stem is pulled towards ground and covered with soil, from which roots will develop after few days and it will grow into a new plant by detaching from parent plant. Examples- lemon, chrysanthemum.



Question 24.

a. What is a tuber? Give example.

b. Name one commonly used vegetable which is propagated by using tubers.


Answer:

a. Tubers are thickened, enlarged modified stems which are found underground and are used as storage organs of nutrients. They serve as a food reserve for plants. Example- potato, yam.

b. Potato is propagated by using tubers. Buds present in the tuber of potatoes can grow into a new plant.



Question 25.

What is meant by vegetative propagation?


Answer:

The growth of new plants from vegetative parts of the plant like roots, stem, leaves other than the seeds is called vegetative propagation.

There are various methods like cutting, layering, grafting which are artificial methods of vegetative propagation etc. Natural methods include modified tuberous roots, stems, buds on leaves etc.



Question 26.

Explain how, new Bryophyllum plants can be produced from the leaves of the old plant?

Illustrate your answer with the help of a labelled diagram.


Answer:

In Bryophyllum adventitious buds develop from the notches of leaves when they fall down into moist soil and on getting proper conditions for growth, new plants arises from them. This is one example of natural method of vegetative propagation.



Question 27.

Name one organism which reproduces by fission and another by fragmentation.

Describe these processes with example.


Answer:

Amoeba reproduces by fission and spirogyra by fragmentation.

i. Fission: It is the process in which a unicellular organism splits into two or more daughter cells. They are mainly of two types- Binary fission which is seen in Amoeba, Paramecium and Multiple fission seen in Plasmodium.



The process by which there is division of a parent cell into several daughter cells is called multiple fission. During this process the nucleus of parent cell divides into many daughter nuclei along with the division of cytoplasm.


Binary fission



The genetic material first duplicates through mitosis leading to duplication of nucleus through karyokinesis and a constriction appears in the cell membrane which deepens and finally a single parent cell divides into two daughter cells. The division of cytoplasm is called cytokinesis. This mode of asexual reproduction is called binary fission.


ii. Fragmentation- In this case organism after maturation breaks into smaller fragments and each fragment grows into a new individual. This process is called fragmentation.




Question 28.

What is the meaning of multiple fission : Describe.


Answer:

The process by which there is division of a parent cell into several daughter cells is called multiple fission. During this process the nucleus of parent cell divides into many daughter nuclei along with the division of cytoplasm.

Multiple fission seen in Plasmodium.




Question 29.

Describe the method of reproduction in fungus.


Answer:

Fungi reproduce asexually by budding or spore formation.

Fungi like yeast reproduce by budding whereas mucor reproduce by spore formation.


Yeast reproduces by budding asexually. A small outgrowth called bud arises from parent yeast cell during favourable conditions. It gradually enlarge, nucleus enlarges and divides into two. One of the nuclei goes to the bud. Bud grows and become larger equal in size to parent cell. It may separate out from parent cell or form chain of buds.



Spores are reproductive parts and Hyphae are non-reproductive parts of Rhizopus.


Rhizopus reproduces through asexual method by spore formation. Spores are produced in sporangia. On maturation the walls of sporangia ruptures and spores are liberated out. They are covered with a thick wall which protects them from adverse conditions. On suitable conditions spores germinate and grow into new hyphae. The hyphae develop an enlarged sporangium. Nucleus within the sporangium divides several times and each nucleus gets surrounded by cytoplasm to form spore which gets matured inside sporangium.