Chapter 2 – (b) Reproduction | Life Science Solution Class 10

Reproduction
Book Name : Life Science And Environment
Subject : Life Science
Class : 10 (Madhyamik)
Publisher : Calcutta Book House (P) Ltd
Unit Name : Continuity Of Life
Chapter Name : Reproduction

Objective-type questions (MCQ)

Question 1

What is the type of Reproduction found in water hyacinth?
  1. Vegetative 
  2. Asexual 
  3. Sexual
  4. Asexual and sexual

Answer

Asexual and sexual

Explanation:

Water hyacinth can reproduce both vegetatively and sexually. Therefore, the correct answer is option D – Asexual and sexual.

Question 2

Unit of Asexual Reproduction is-
  1. Stem
  2. Bud 
  3. Flower
  4. Spore

Answer

spore

Explanation:

The name of the unit of asexual reproduction in plants is spore.

Question 3

Leaf buds are responsible for the formation of new individuals in-
  1. Mango
  2. Jackfruit 
  3. Spirogyra
  4. Bryophyllum

Answer

Bryophyllum

Explanation:

Leaf buds are responsible for the formation of new individuals in Bryophyllum.

Bryophyllum is a succulent plant that is capable of producing plantlets along the edges of its leaves. These plantlets can then fall off the parent plant and grow into new individuals.

Question 4

Unisexual flower is found in-
  1. Jasmine
  2. Rose 
  3. Lotus 
  4. Cucurbita

Answer

Cucurbita

Explanation:

Unisexual flowers are found in Cucurbita.

Cucurbita is a genus of plants that includes various species of pumpkins, squash, and gourds. The flowers of these plants are unisexual, meaning they have either male or female reproductive structures, but not both.

Question 5

Conjugation is the method of Reproduction in-
  1. Spirogyra
  2. Fern 
  3. Moss
  4. Agaricus

Answer

Spirogyra

Explanation:

Conjugation is the method of Reproduction in Spirogyra.

Spirogyra is a green alga that reproduces both sexually and asexually. A conjugation is a form of sexual reproduction in Spirogyra. During conjugation, two filaments of Spirogyra come close together and form conjugation tubes between them.

Question 6

When root buds develop into new plants, then the method is called-

  1. Asexual
  2. Vegetative
  3. Sexual 
  4. Parthenogenesis.

Answer

vegetative

Explanation:

When root buds develop into new plants, the method is called vegetative propagation.

Vegetative propagation is a form of asexual reproduction that involves the formation of new individuals from vegetative structures such as roots, stems, and leaves, rather than from seeds or spores.

Question 7

The modified subaerial stem is detached and produce small daughter plants, this method of Reproduction is called-

  1. Grafting
  2. Gootee
  3. Vegetative Reproduction
  4. Fragmentation.

Answer

vegetative reproduction

Explanation:

The modified subaerial stem is detached and produces small daughter plants is an example of vegetative reproduction. It is a natural method of reproduction where new plants are formed from different parts of the parent plant.

Question 8

After fertilization, the diploid cell is called-

  1. Embryo
  2. Zygote
  3. Spore 
  4. Reproductive cell.

Answer

zygote

Explanation:

After fertilization, the haploid male and female gametes fuse together to form a diploid cell called a zygote. The zygote undergoes various developmental processes to form an embryo which eventually develops into a new individual. Therefore, the correct answer is option (b) Zygote.

Question 9

After fertilization ovary is converted into-
  1. Seed 
  2. Endosperm 
  3. Fruit
  4. Embryo

Answer

fruit

Explanation:

After fertilization, the ovary is converted into a fruit. The fruit protects and aids in the dispersal of the seeds. The seeds contain the embryo which develops into a new plant under suitable conditions.

Question 10

Grafting is a type of 
  1. Vegetative Reproduction 
  2. Sexual Reproduction 
  3. Asexual Reproduction
  4. Clonal propagation.

Answer

vegetative reproduction

Explanation:

Grafting is a type of vegetative reproduction in plants. In grafting, a stem or a bud from one plant is attached to the root or stem of another plant, which then grows to form a new plant with the desired characteristics.

Question 11

The animal which reproduces by fragmentation is-
  1. Toad
  2. Earthworm
  3. Amoeba
  4. Hydra.

Answer

hydra

Explanation:

Fragmentation is a type of asexual Reproduction where a parent organism splits into fragments, each of which can develop into a new individual. Hydra is an animal that reproduces by fragmentation, where a small portion of the parent’s body grows into a miniature Hydra.

Question 12

Budding is commonly found in the animal-
  1. Amoeba 
  2. Toad 
  3. Hydra
  4. Man.

Answer

hydra

Explanation:

Budding is a form of asexual reproduction that is commonly found in simple animals like hydra, which is a freshwater organism. During budding, a new individual organism develops from an outgrowth or bud due to repeated cell division at one particular site. The bud then grows and detaches itself from the parent body to form a new individual.

Question 13

In sexual Reproduction when the two gametes that unit are equal in size then it is called-
  1. Isogamy
  2. Anisogamy
  3. Oogamy
  4. Syngamy.

Answer

isogamy

Explanation:

When the two gametes that unite are equal in size and morphology, it is called isogamy. This type of gamete is found in some algae, fungi, and primitive plants. The isogamous gametes are generally flagellated, motile, and similar in appearance. The fusion of two isogametes forms a diploid zygote.

Question 14

An animal exhibiting internal fertilization is-
  1. Hydra 
  2. Earthworm 
  3. Pigeon 
  4. Man.

Answer

man

Question 15

Sexual characters found in larval stage is called-
  1. Pedogenesis
  2. Embryo
  3. Oogenesis
  4. Parthenogenesis.

Answer

pedogenesis

Explanation:

The term used to describe the presence of sexual characteristics in the larval stage of an organism is called Pedogenesis. It is a form of neoteny where juvenile characteristics are retained in adults. Pedogenesis is commonly observed in certain insect species, such as beetles and flies.

Question 16

In which process the fragmented parts of some animals develop to form a complete individual? 

  1. Metamorphosis 
  2. Redevelopment 
  3. Regeneration 
  4. Automixis.

Answer

regeneration

Explanation:

The process in which the fragmented parts of some animals develop to form a complete individual is called “regeneration”.

Question 17

In which method the broken parts of the body of some animals regenerate the broken parts and develop into complete organisms?

  1. Metamorphosis
  2. Transformation 
  3. Fragmentation
  4. Redevelopment

Answer

regeneration

Explanation:

The method in which the broken parts of the body of some animals regenerate the broken parts and develop into complete organisms is called “regeneration”.

Question 18

The chromosome number of a reproductive cell is-

  1. Same number
  2. Double number 
  3. Half number
  4. Triple number.

Answer

half number

Explanation:

The chromosome number of a reproductive cell is half of the total number of chromosomes found in the somatic or body cells of an organism. This is because during sexual reproduction, two haploid gametes (sperm and ovum) combine to form a diploid zygote with a complete set of chromosomes. Therefore, the chromosome number of a reproductive cell is usually half of the diploid number.

Question 19

In the case of which organisms offspring develop from female gametes without fertilization is found in-
  1. Pigeon 
  2. Toad 
  3. Mango plant 
  4. Honey-bee

Answer

honey-bee

Explanation:

The case of offspring developing from female gametes without fertilization is found in “honey-bee”. This type of Reproduction is called “parthenogenesis”.

Question 20

Parthenogenesis is found in the animal-
  1. Man 
  2. Honey-bees
  3. Cockroach
  4. Earthworm

Answer

honey-bees

Explanation:

Parthenogenesis is a form of asexual reproduction where the offspring develops from an unfertilized egg. It is found in some invertebrates, including certain species of honeybees and cockroaches. However, parthenogenesis is not found in mammals such as humans, and earthworms reproduce sexually.

Question 21

Sexual dimorphism is found in-
  1. Earthworm 
  2. Toad 
  3. Tiger
  4. Cockroach.

Answer

tiger

Explanation:

Sexual dimorphism is the condition where the male and female individuals of a species exhibit different physical characteristics beyond the differences in their sexual organs. Out of the given options, Tiger is an example of a species with sexual dimorphism. Male tigers are generally larger and have thicker manes compared to female tigers.

Question 22

The fertilized egg is known as
  1. Zygote 
  2. Sperm 
  3. Spore 
  4. Zygospore

Answer

zygote

Explanation:

When a sperm cell fuses with an egg cell during sexual reproduction, it forms a single-celled zygote. The zygote contains a full set of chromosomes and has the potential to develop into a complete organism. Therefore, the fertilized egg is known as “zygote”.

Fill in the blanks

Question

  1. The ability of living organisms to produce more organisms exactly like themselves is referred to as ____.
  2. Formation of offspring from detachment of parental plant is called ____ Reproduction.
  3. A single parental plant cell divides or forms spores for the formation of new individuals is called ______ Reproduction.
  4. Unit of asexual Reproduction is ____.
  5. The cell which produces spores is called ____.
  6. Flagellated spore is called ____.
  7. The type of Reproduction is called ____ where two different types of gametes are required.
  8. Megaspore mother cell divides by ____.
  9. Vegetative Reproduction occurs in ____.
  10. Budding is a type of ____ Reproduction.
  11. Zygote is the product of the union of ____ and ____ gametes.
  12. Non-motile spore is called ____.
  13. In grafting rooted plant is called ____.
  14. Cutting and grafting are the examples of ____ Reproduction.
  15. Double fertilization takes place in ____ plant.
  16. Pollination is the process of transfer of pollen grains from ____ to ____.
  17. ____ reproduces by only asexual method.
  18. When both male and female sexes are present in the animal body, it is called ____.
  19. Binary fission occurs in ____.
  20. Multiple fission or sporulation found in ____.
  21. In ____ broken parts regenerate the missing parts and develop into complete organisms.
  22. The sexual reproductive unit is called ____.

Answer

  1. Reproduction
  2. Budding
  3. Asexual
  4. Unit of vegetative reproduction
  5. Sporocyte
  6. Zoospore
  7. Sexual reproduction
  8. Meiosis
  9. Plants
  10. Asexual
  11. Male, female
  12. Aplanospore
  13. Scion
  14. Vegetative
  15. Angiosperm
  16. Anther, stigma
  17. Hydra
  18. Hermaphrodite
  19. Amoeba
  20. Plasmodium
  21. Regeneration
  22. Gamete

Very Short Answer (VSA) type questions

Question 1

What is the term used the ability of living organisms to produce more organisms exactly alike?

Answer

asexual reproduction.

Question 2

“The detached parts of an organism form a new individual”-What is this method of Reproduction called?
 

Answer

This method of reproduction is called fragmentation.

Question 3

What is the method of Reproduction when spores are responsible for the formation of offspring? 

Answer

The method of reproduction when spores are responsible for the formation of offspring is called spore formation or sporogenesis.

Question 4

When two different gametes are united for Reproduction? 

Answer

When two different gametes (sperm and egg) are united for reproduction, the process is called sexual reproduction.

Question 5

What is it called when an unfertilized egg develops into a new individual?

Answer

The process where an unfertilized egg develops into a new individual is called parthenogenesis.
 

Question 6

What is the unit of Sexual Reproduction?

Answer

The unit of sexual reproduction is the gamete.

Question 7

In which method of Reproduction do plants form spores? 

Answer

Plants that reproduce by spore formation are called “sporophytes” and this method of reproduction is called “sporogenesis” or “spore production”. Examples of plants that reproduce by spores are ferns, mosses, and fungi.

Question 8

What is the unit of asexual Reproduction?

Answer

The unit of asexual reproduction is the vegetative structure such as the root, stem, or leaf node that is capable of developing into a new individual without fusion with another reproductive cell.

Question 9

What is called the aplanospore?

Answer

An aplanospore is a type of spore produced by certain algae, such as diatoms, that lacks flagella and is not capable of self-movement.

Question 10

Give an example of artificial vegetative Reproduction.

Answer

Grafting is an example of artificial vegetative reproduction, where a stem or bud of one plant is joined to the stem or root of another plant in order to create a new plant with desirable traits.

Question 11

What do you mean by cutting?

Answer

Cutting refers to a vegetative propagation method where a part of a plant is cut and placed in soil or water in order to grow into a new plant.

Question 12

What is grafting?

Answer

Grafting is an artificial vegetative propagation method in which a stem or bud of one plant is joined to the stem or root of another plant in order to create a new plant with desirable traits.

Question 13

Cite two examples of plants which reproduce by asexual method.

Answer

Potato and ginger are two examples of plants that reproduce by asexual methods.

Question 14

If a diploid organism reproduces by parthenogenesis method all the new individuals are diploid-Is the statement true?

Answer

If a diploid organism reproduces by the parthenogenesis method, then all the new individuals will also be diploid, as they will contain the same number of chromosomes as the parent organism. Therefore, the statement is true.

Question 15

Give an example of a plant where fragmentation is the method of Reproduction.

Answer

Spirogyra, a type of green algae, reproduces by fragmentation, where a filament breaks into fragments, and each fragment can grow into a new individual.

Question 16

Give an example of a plant that reproduces by budding. 

Answer

Yeast is an example of a plant that reproduces by budding.

Question 17

Cite two examples where an underground modified stem reproduces by vegetative means.

Answer

Two examples of plants where underground modified stem reproduces by vegetative means are ginger (Zingiber officinale) and turmeric (Curcuma longa).

Question 18

In which plant shoots arise from the leaf margin?

Answer

In Bryophyllum (Bryophyllum spp.), shoots arise from the leaf margin.

Question 19

Is grafting a method of sexual Reproduction? 

Answer

No, grafting is a method of vegetative propagation, not sexual reproduction.

Question 20

Name a plant that reproduces by root. 

Answer

Sweet potato (Ipomoea batatas) is a plant that reproduces by root, specifically through the development of adventitious roots that produce new plants.

Question 21

Is the embryo haploid or diploid? 

Answer

An embryo is diploid, as it is formed by the fusion of a haploid sperm cell with a haploid egg cell during fertilization.

Question 22

Name one animal that reproduces by only asexual methods.

Answer

Hydra is an example of an animal that reproduces exclusively by asexual reproduction.

Question 23

Which type of Reproduction is found in amoeba during favourable conditions? 

Answer

Amoeba reproduces asexually by binary fission during favourable conditions.

Question 24

Give an example of an invertebrate where parthenogenesis is the method of Reproduction. 

Answer

Daphnia is an example of an invertebrate where parthenogenesis is a common method of reproduction.

Question 25

In which type of Reproduction gametes are formed?

Answer

In sexual reproduction, gametes are formed.

Short Answer (SA) type questions

Question 1

What is Reproduction?

Answer

Reproduction is the biological process by which new individuals of the same species are produced. It involves the transmission of genetic information from parent to offspring.

Question 2

What is vegetative Reproduction?
 

Answer

Vegetative reproduction is a form of asexual reproduction in plants where new individuals are produced from vegetative structures such as roots, stems, or leaves, rather than from seeds or spores. The new individuals are genetically identical to the parent plant.

Question 3

Mention only two importances of Reproduction.

Answer

The two importances of Reproduction are

  1. Ensures species continuity.
  2. Promotes genetic diversity.

Question 4

What are the different types of Reproduction found in organisms?

Answer

The different types of reproduction found in organisms are:

  1. Sexual reproduction: involves the fusion of gametes to produce offspring with genetic variation.
  2. Asexual reproduction: involves the production of offspring without the fusion of gametes and results in offspring that are genetically identical to the parent.
  3. Vegetative reproduction: involves the production of new individuals from vegetative structures such as roots, stems, or leaves.
  4. Parthenogenesis: involves the development of an embryo from an unfertilized egg.

Question 5

What is sexual Reproduction? Where is it seen?

Answer

Sexual reproduction is a type of reproduction in which two different gametes (sperm and egg) unite to form a new individual with genetic variation. It is seen in most multicellular organisms, including animals, plants, and fungi.
 

Question 6

What is parthenogenesis?

Answer

Parthenogenesis is a type of asexual reproduction in which an unfertilized egg develops into a new individual without being fertilized by sperm. This form of reproduction is found in certain species of animals, such as some insects and reptiles, and some plants.

Question 7

(a) Among the asexually and sexually reproducing organisms, where is meiosis essential? (b) What are non-motile spores?

Answer

(a) Meiosis is essential in sexually reproducing organisms, as it is the process by which gametes are formed, which contain half the number of chromosomes as the parent cell. Meiosis is not essential in asexually reproducing organisms, as they produce offspring that are genetically identical to the parent cell and do not require the fusion of gametes.

(b) Non-motile spores are a type of spore that cannot move by themselves and rely on external factors such as wind, water, or animals to disperse them to new locations. These spores are produced by many different types of organisms, including plants, fungi, and some bacteria.

Question 8

What is grafting?

Answer

Grafting is a technique of vegetative propagation in which a stem, bud, or shoot of one plant is inserted into the stem, branch, or root of another plant so that they grow together into a single plant. It is commonly used in horticulture to propagate fruit trees, ornamental trees, and other plants.

Question 9

What are the different natural methods of vegetative Reproduction?

Answer

The different natural methods of vegetative reproduction include:

  1. Fragmentation: breaking of a plant into fragments, each of which can develop into a new individual.
  2. Budding: formation of a small outgrowth or bud that develops into a new individual.

Question 10

What is fission? Give examples. 

Answer

Fission is a type of asexual reproduction in which an organism splits into two or more parts, each of which can develop into a new individual. Examples of organisms that reproduce by fission include bacteria, protists like amoeba, and some invertebrates like sea anemones and planarians.

Question 11

What are the differences between binary and multiple fission? 

Answer

Binary Fission Multiple Fission
Involves the division of one cell into two daughter cells. Involves the division of one cell into many daughter cells.
Occurs in unicellular organisms such as bacteria and protists. Occurs in some unicellular and multicellular organisms such as algae and some invertebrates.

Question 12

What is budding? Give an example. 

Answer

Budding is a type of asexual reproduction in which a new individual develops as a small outgrowth or bud on the parent organism and eventually separates to become an independent individual. An example of an organism that reproduces by budding is the hydra, a small freshwater animal that can produce new individuals through budding from its body wall.

Question 13

What is fragmentation ? 

Answer

Fragmentation is a method of asexual reproduction in which a parent organism breaks into fragments, and each fragment can grow into a new individual. This method is common in organisms such as certain types of algae and fungi, where the fragments can grow into new individuals under favourable conditions.

Question 14

Give examples of underground stems that reproduce asexually. 

Answer

Examples of underground stems that reproduce asexually include rhizomes of ginger, turmeric, and bamboo; bulbs of onion, garlic, and tulips; corms of gladiolus; and tubers of potato and yam.

Question 15

What are heterosporous plants? 

Answer

Heterosporous plants are plants that produce two different types of spores: microspores, which develop into male gametophytes, and megaspores, which develop into female gametophytes. These spores are produced in different structures, such as microsporangia and megasporangia, respectively. Heterosporous plants are typically seed plants, including most gymnosperms and all angiosperms.

Question 16

What is anisogamy? 

Answer

Anisogamy is a type of sexual reproduction where the two uniting gametes are structurally different, it cannot be differentiated into male or female gametes. Anisogamy is found in chlamydomonas.

Question 17

What do you mean by oogamy ? 

Answer

Oogamy is a type of sexual reproduction in which the female gamete or egg is much larger than the male gamete or sperm. In this process, the egg remains stationary and is fertilized by a smaller, motile sperm that swims to the egg. Oogamy is common in many organisms, including animals, algae, and plants.

Question 18

What is a spore? 

Answer

A spore is a reproductive structure that is capable of developing into a new individual without sexual fusion. Spores are produced by plants, fungi, and some bacteria as a means of asexual reproduction and dispersal. Spores are often adapted to survive harsh environmental conditions and can be transported over long distances by wind, water, or other means.

Question 19

What is asexual Reproduction? 

Answer

Asexual reproduction is a type of reproduction in which new individuals are produced without the involvement of gametes or fertilization. In asexual reproduction, a single-parent organism produces offspring that are genetically identical to itself. Asexual reproduction occurs in many organisms, including bacteria, fungi, plants, and some animals.

Question 20

What is fertilization?

Answer

Fertilization is the process in sexual reproduction in which a sperm cell fuses with an egg cell to form a zygote. Fertilization typically occurs in the female reproductive system, where the sperm and egg meet and fuse together to form a single cell with a complete set of genetic material. This process combines the genetic material of both parents and produces offspring with unique genetic characteristics.

Question 21

What is syngamy ?

Answer

Syngamy is another term for fertilization, which is the process in sexual reproduction in which a sperm cell fuses with an egg cell to form a zygote. During syngamy, the genetic material of the two parent cells combines to produce a new individual with a unique set of genetic characteristics.

Question 22

What do you mean by sperm and ovum in plants? 

Answer

In plants, the terms sperm and ovum are used to refer to the male and female gametes, respectively. The sperm in plants are typically produced by the male reproductive organs, such as anthers in flowers or male cones in conifers. The ovum, on the other hand, is produced by the female reproductive organs, such as the ovules in flowers or female cones in conifers.

Question 23

When is an animal said to be oviparous?

Answer

An animal is said to be oviparous if it lays eggs that develop and hatch outside the mother’s body. In oviparous animals, fertilization typically occurs internally, but the developing embryo is protected and nourished within an egg outside the mother’s body until it is ready to hatch.

Question 24

What is a hermaphrodite animal? 

Answer

A hermaphrodite animal is an animal that has both male and female reproductive organs and is capable of producing both eggs and sperm. Hermaphroditism can be either simultaneous, where an individual has both male and female reproductive organs at the same time, or sequential, where an individual changes sex at some point during its life.

Question 25

Mention two importance of vegetative Reproduction.

Answer

Two importance of vegetative reproduction are:

  1. It allows plants to propagate without the need for pollination or fertilization, which can be advantageous in environments where pollinators or mates may be scarce.
  2. It allows plants to produce offspring that are genetically identical to the parent, which can be useful for preserving desirable traits or characteristics in agriculture and horticulture.

Long Answer (LA) type questions

Question 1

What is cutting? Give example.

Answer

Cutting is a method of vegetative propagation where a part of a plant, such as a stem, leaf, or root, is cut and planted to grow a new plant. The cutting is taken from a parent plant and is placed in water or soil until roots and shoots begin to develop. Once the new plant has established roots, it can be transplanted to a pot or garden bed to grow into a mature plant. Examples of plants that can be propagated by cuttings include succulents, roses, and herbs such as basil and mint. This method allows gardeners and farmers to create new plants that are genetically identical to the parent plant.

Question 2

What is grafting?

Answer

Grafting is a method of vegetative propagation in which a part of one plant (the scion) is attached to a separate plant (the rootstock) in order to grow a new plant. Grafting is typically done by making a clean cut on both the scion and the rootstock and joining them together, then wrapping the graft union with a tape or wax to hold it in place. The scion will eventually grow into a new plant that is genetically identical to the original plant. Grafting is commonly used in agriculture and horticulture to produce fruit trees, ornamental plants, and other crops that have desirable traits or characteristics.

Question 3

What are the advantages of vegetative Reproduction?

Answer

Some advantages of vegetative reproduction are:

  1. It allows plants to reproduce quickly and efficiently.
  2. It produces offspring that are genetically identical to the parent plant, ensuring that desirable traits are preserved.
  3. It allows plants to avoid the need for pollinators or fertilisers.
  4. It can be used to propagate plants that are difficult to grow from seeds.
  5. It allows for the production of large quantities of plants from a single parent plant.

Question 4

Why do we prefer vegetative over sexual Reproduction?

Answer

Vegetative reproduction is preferred over sexual reproduction in some cases because it offers several advantages, including:

  1. The offspring are genetically identical to the parent, ensuring that desirable traits are preserved.
  2. It allows plants to propagate without the need for pollination or fertilization.
  3. It can be a faster and more efficient method of propagation than sexual reproduction.
  4. It can be used to produce large quantities of plants from a single parent plant.
  5. It can be used to propagate plants that are difficult to grow from seed.

Question 5

Discuss alternation of generation with example.

Answer

Alternation of generations is a type of life cycle found in some plants and algae in which there are two distinct multicellular stages, a haploid gametophyte stage and a diploid sporophyte stage, that alternate with each other.

One example of alternation of generations is found in the life cycle of mosses. The gametophyte stage of the moss is the dominant stage, and it produces haploid gametes (eggs and sperm) that fuse to form a diploid zygote. The zygote develops into the sporophyte stage, which is dependent on the gametophyte for nutrition. The sporophyte produces spores through meiosis, which are released and develop into new gametophytes, completing the life cycle.

Question 6

What is multiple fission? Give example.

Answer

multiple fission

Multiple fission is a type of asexual reproduction in which a single parent organism divides into multiple daughter cells, each of which develops into a new individual.

One example of multiple fission is found in the life cycle of some protozoa, such as Plasmodium which causes malaria. During multiple fission, the parent cell undergoes several rounds of nuclear division without cytokinesis, resulting in a multinucleate cell. The multinucleate cell then divides into multiple daughter cells, each containing a single nucleus and other cell organelles, which develop into new individuals.

Question 7

What do you mean by fragmentation and budding in animals?

Answer

Fragmentation and budding are methods of asexual reproduction found in some animals.

Starfish

Fragmentation is a process in which the parent organism breaks into pieces, and each piece can grow into a new individual. This is commonly found in some species of sea stars, where a single arm of the star can grow into a new organism after detaching from the parent.

hydra budding

Budding is a process in which a new individual develops as an outgrowth or bud on the parent organism. This is found in many animals, including hydra and some jellyfish. The bud grows and eventually separates from the parent, forming a new individual.

Both fragmentation and budding allow animals to reproduce asexually, without the need for a mate or fertilization. However, these methods also limit genetic diversity and the ability to adapt to changing environments, which can be a disadvantage compared to sexual reproduction.

Question 8

(a) What is Reproduction? (b) Discuss briefly the importance of Reproduction. (c) Mention the types of Reproduction.

Answer

a) Reproduction is the biological process by which living organisms produce offspring with genetic information inherited from their parents.

b) Reproduction is essential for the continuation of species and the survival of life on earth. Some of the key importance of reproduction are:

  • Reproduction allows for the continuation of a species by producing new individuals.
  • It enables genetic diversity within a population and among different species, which increases the chances of survival and adaptation to changing environments.
  • It helps to maintain a healthy ecosystem by providing food, pollination, and other ecological services.
  • It allows for the transmission of cultural and social values from one generation to another.

c) There are two main types of reproduction: asexual reproduction and sexual reproduction. Asexual reproduction involves the production of offspring without the involvement of gametes or fertilization. It produces genetically identical offspring, and examples include fragmentation, budding, and vegetative reproduction. Sexual reproduction involves the fusion of gametes, which produces genetically diverse offspring. It is found in most plants and animals and includes processes such as meiosis, fertilization, and alternation of generations.

Question 9

Explain with examples of different vegetative Reproductions in plants.

Answer

Vegetative reproduction is a type of asexual reproduction in which new plants are produced from vegetative parts of the parent plant, such as stems, leaves, or roots, without the need for seeds or spores. Here are some examples of different types of vegetative reproduction in plants:

  1. Cutting: A stem or leaf cutting is placed in soil or water, and it develops roots and grows into a new plant. For example, rose, sugarcane, and mint can be propagated by stem cuttings.
  2. Layering: In this method, a branch of the parent plant is bent down to the soil and covered with soil or mulch. The branch develops roots, and a new plant grows from it. For example, blackberry and raspberry plants can be propagated by layering.
  3. Grafting: This involves joining a stem or bud from one plant, called the scion, onto the rootstock of another plant. The two parts will grow together and form a new plant that is a combination of the two. For example, fruit trees like apples and pears are often propagated by grafting.
  4. Bulb division: Bulbous plants such as tulips and daffodils can be propagated by dividing the bulbs into smaller sections, each of which can grow into a new plant.
  5. Rhizome division: Plants such as ginger and turmeric can be propagated by dividing their rhizomes, which are underground stems that produce new shoots and roots.

Question 10

(a) What is vegetative Reproduction? (b) Write in brief of two natural vegetative Reproductions in plants. 

Answer

a) Vegetative reproduction is a type of asexual reproduction in which new plants are produced from vegetative parts of the parent plant, such as stems, leaves, or roots, without the need for seeds or spores.

b) Two examples of natural vegetative reproduction in plants are:

  1. Runners: In some plants, such as strawberries and spider plants, the parent plant produces long, thin stems called runners that grow along the ground and produce new plantlets at their nodes. The plantlets develop their own roots and eventually become independent plants.
  2. Bulbils: Some plants, such as garlic and onion, produce small bulbils at the top of their stems, which can grow into new plants. The bulbils can be separated from the parent plant and planted directly into soil to grow into new plants.

Question 11

Explain with examples of fragmentation and bulbil formation in plants.

Answer

Fragmentation and bulbil formation are two methods of vegetative reproduction in plants. Here’s an explanation of each with an example:

  1. Fragmentation: In fragmentation, a piece of the plant breaks off, and each piece can grow into a new individual. For example, some species of algae can reproduce by fragmentation. When a filament of the alga breaks, each fragment can develop into a new filament, which is genetically identical to the parent plant.
  2. Bulbil Formation: In bulbil formation, small bulbs or bulb-like structures develop on the stem or leaves of a plant. These bulbils can grow into new plants when they detach from the parent plant and fall to the ground. For example, some species of garlic and onion produce bulbils that can be used to propagate new plants.

Question 12

Write in short the vegetative Reproduction in Bryophyllum, Adiantum, Dalhia, Zingiber (Zinger) and Oxalis.

Answer

  1. Bryophyllum: Bryophyllum reproduces vegetatively through its specialized leaves that have small plantlets forming along their edges. These plantlets can grow into new plants when they detach from the parent leaf and fall to the ground.
  2. Adiantum: Adiantum reproduces vegetatively through its rhizomes, which produce new fronds and roots. The new fronds grow from the rhizomes and form a new plant.
  3. Dahlia: Dahlia reproduces vegetatively through tubers, which are swollen underground stems. Each tuber has buds that can grow into new plants when the tuber is planted in the soil.
  4. Zingiber (Zinger): Zingiber reproduces vegetatively through its rhizomes, which produce new shoots and roots. These rhizomes can be separated to propagate new plants.
  5. Oxalis: Oxalis reproduces vegetatively through its bulbs, which produce new plants. The bulbs can be separated to propagate new plants.

Question 13

Discuss any two methods of artificial vegetative Reproduction.

Answer

Artificial vegetative reproduction refers to the process of propagating plants by human intervention rather than natural means.

Two methods of artificial vegetative reproduction are:

  1. Grafting: Grafting is a technique in which two plants are combined to create a new plant with desirable traits. In grafting, a stem or bud from one plant called the scion, is attached to the rootstock of another plant. The two plants then grow together, forming a single plant with the desired traits of both parent plants. Grafting is commonly used in fruit tree cultivation, where it is used to create trees with desirable fruit characteristics.
  2. Cuttings: Another method of artificial vegetative reproduction is taking cuttings from a parent plant and rooting them to create new plants. Cuttings are pieces of stem or leaf that are cut from the parent plant and planted in soil or another growing medium. Once the cutting forms roots, it can be transplanted into its own pot or directly into the ground. This method of reproduction is commonly used for plants that are difficult to propagate by seed, such as some types of roses or herbs.

Question 14

What are the importance of vegetative Reproduction

Answer

Here are some very short points on the importance of vegetative reproduction:

  1. Allows for the production of new offspring without the need for sexual reproduction or the production of seeds.
  2. Helps plants quickly and efficiently produce new individuals that are genetically identical to the parent plant.
  3. Allows for the propagation of plants with desirable traits, such as disease resistance or fruit size.
  4. Useful for plants that are difficult to propagate by seed, such as some types of roses or herbs.
  5. Can be used to create large numbers of plants for agricultural or commercial purposes.

Question 15

What are cutting and grafting?

Answer

Cutting and grafting are two methods of vegetative propagation in plants.

Cutting involves taking a piece of a stem or leaf from a parent plant and planting it in soil or another growing medium. The cutting will grow into a new plant, with the same genetic characteristics as the parent plant.

Grafting is the process of attaching a piece of one plant, known as the scion, onto another plant, known as the rootstock. The two plants will then grow together, with the scion plant growing on top of the rootstock plant. This method is often used to create hybrid plants, with desirable traits from both parent plants. Grafting is commonly used in fruit tree cultivation, where it is used to create trees with desirable fruit characteristics.

Both cutting and grafting are useful methods for propagating plants, especially those that are difficult to grow from seed. These methods allow growers to produce large numbers of plants that are genetically identical to the parent plant, with desirable traits.

Question 16

What are the differences between vegetative and asexual Reproductions?

Answer

Vegetative Reproduction Asexual Reproduction
1. Involves the production of new individuals from non-reproductive parts of a plant (e.g. stem, leaf, root) Involves the production of new individuals from a single parent organism
2. The offspring are genetically identical to the parent plant The offspring may have genetic variation due to mutations or genetic recombination
3. No specialized reproductive structures are involved Specialized reproductive structures such as spores or gametes are involved
4. Commonly used in horticulture to propagate desirable traits Commonly used by single-celled organisms, fungi, and some plants to rapidly produce large numbers of offspring
5. Examples include cutting, grafting, and bulbils Examples include binary fission, multiple fission, and budding

Question 17

What are the differences between asexual and sexual Reproduction?

Answer

Aspect Asexual Sexual
Parent Involvement Single parent offspring production Two parents contribute to offspring
Genetic Diversity Limited genetic diversity High genetic diversity
Offspring Genetically identical offspring Genetically unique offspring
Examples Binary fission, budding Fertilization in animals, pollination in plants

Question 18

Describe the various types of asexual Reproduction in animals.

Answer

Asexual reproduction is less common in animals than in plants, but there are several methods by which animals can reproduce asexually.

Some examples of asexual reproduction in animals are:

  1. Binary fission: This is a type of asexual reproduction seen in unicellular organisms, such as bacteria and protozoa. In binary fission, the parent cell divides into two genetically identical daughter cells.
  2. Budding: Budding is a form of asexual reproduction seen in invertebrates, such as hydra and jellyfish. In this process, a small bud or outgrowth forms on the parent organism and grows into a genetically identical offspring.
  3. Fragmentation: Some animals, such as sea stars, can reproduce asexually by breaking off a piece of their body and regenerating a new organism from the fragment.
  4. Parthenogenesis: This type of asexual reproduction occurs in some insects, reptiles, and fish. In parthenogenesis, the female organism produces offspring without the need for fertilization from a male. The offspring are genetically identical to the mother.
  5. Apomixis: This type of asexual reproduction is found in some plants and also in a few animals, such as certain species of whiptail lizards. In apomixis, the female organism produces offspring that are genetically identical to the mother, without the need for fertilization from a male.

Question 19

(a) What is an alternation of generation? (b) Draw the life cycle of Monocystis showing haploid and diploid generations.

Answer

(a) Alternation of generation is a type of life cycle seen in some organisms, particularly in plants and algae. In this life cycle, the organism alternates between a haploid (n) and diploid (2n) phase in its life cycle. The haploid phase produces gametes through mitosis, while the diploid phase produces spores through meiosis.

(b) Monocystis is a genus of parasitic protists that infects the digestive tract of earthworms. Its life cycle involves the alternation of generations, with haploid and diploid phases. Here is a simplified diagram of the Monocystis life cycle:

  1. Haploid phase (n): The haploid phase begins with the release of haploid spores from the Monocystis organism. These spores are released into the environment and are ingested by an earthworm.
  2. Diploid phase (2n): Once inside the earthworm, the spores release haploid cells called sporozoites. These sporozoites infect the earthworm’s digestive tract and undergo asexual reproduction, producing many diploid cells called schizonts.
  3. Haploid phase (n): The schizonts then undergo meiosis, producing haploid cells called gametocytes.
  4. Haploid phase (n): The gametocytes then undergo mitosis to produce haploid gametes, which then fuse to form a diploid zygote.
  5. Diploid phase (2n): The zygote then undergoes mitosis to produce a diploid Monocystis organism, which continues the cycle by producing spores.