Extra 30 short-answer questions from the Chapter:7 "How Do Organisms Reproduce?" chapter of Class 10 CBSE Science, along with their answers.

 

What is asexual reproduction? Give two examples.

 

Answer:

Asexual reproduction is the mode of reproduction where offspring are produced by a single parent without gamete fusion.

Examples:

Binary fission in Amoeba

Budding in Hydra

 

What is binary fission? Explain with an example.

 

Answer:

Binary fission is a type of asexual reproduction in which an organism splits into two identical daughter cells.

Example:

In Amoeba, the nucleus divides first, followed by the cytoplasm, forming two identical cells.

 

What is budding? Explain with an example.

 

Answer:

Budding is a type of asexual reproduction where a small outgrowth (bud) develops on the parent’s body and grows into a new organism.

Example:

Hydra reproduces by budding, where a new Hydra grows from the parent's body and detaches when mature.

 

What is spore formation? Give an example.

 

Answer:

Spore formation is a type of asexual reproduction where an organism produces spores that grow into new individuals.

Example:

Rhizopus (bread

mold

) produces spores in sporangia, which spread and grow into new fungi.

 

Define fragmentation and name an organism that reproduces by this method.

 

Answer:

Fragmentation is a process in which an organism splits into fragments, and each fragment develops into a new organism.

Example:

Planaria reproduces by fragmentation.

 

What is vegetative propagation? Give two examples.

 

Answer:

It is a type of asexual reproduction in which new plants grow from vegetative parts like roots, stems, or leaves.

Examples:

Bryophyllum

reproduces through leaves.

Potato reproduces through underground stems.

 

Why is vegetative propagation beneficial for plants?

 

Answer:

It allows for rapid reproduction.

Produces identical offspring with desirable traits.

Useful for plants that do not produce viable seeds.

 

What is grafting? How is it useful?

 

Answer:

Grafting is a method of artificial vegetative propagation where a stem cutting (scion) is joined to a rooted plant (stock).

It is useful for producing disease-resistant plants and improving fruit quality.

 

Explain the importance of asexual reproduction in unicellular organisms.

 

Answer:

It ensures rapid multiplication.

It does not require complex reproductive structures.

It helps maintain genetic uniformity in stable environments.

 

Differentiate between sexual and asexual reproduction.

 

Answer:

Feature	Asexual Reproduction	Sexual Reproduction
Number of Parents	One	Two
Gamete Formation	Not required	Required
Variation	No variation	Variation occurs
Example	Binary fission in Amoeba	Humans, flowering plants

 

What is pollination? What are its types?

 

Answer:

Pollination is the transfer of pollen from the anther to the stigma of a flower.

Types:

Self-pollination

– Pollen is transferred within the same flower or plant.

Cross-pollination

– Pollen is transferred from one flower to another of the same species.

Differentiate between self-pollination and cross-pollination.

 

Answer:

Feature	Self-Pollination	Cross-Pollination
Pollen Transfer	Same flower or plant	Different plant
Variation	No variation	Genetic variation
Example	Pea plant	Sunflower

What is fertilization in plants? Where does it occur?

 

Answer:

Fertilization is the fusion of male and female gametes.

It occurs in the

ovule

inside the ovary.

What happens to a flower after fertilization?

 

Answer:

Ovary develops into a

fruit

.

Ovules develop into

seeds

.

Petals, stamens, and sepals dry and fall off.

What is double fertilization in plants?

 

Answer:

It is a unique process in flowering plants where two fertilization events occur:

One male gamete

fuses

with the egg cell to form a

zygote

.

Another male gamete fuses with two polar nuclei to form

endosperm

(food for the seed).

What is the function of the seed in plants?

 

Answer:

Seeds protect the embryo.

Store nutrients for growth.

Help in dispersal and reproduction.

What is the role of the ovary in plant reproduction?

 

Answer:

Produces ovules (female gametes).

Develops into fruit after fertilization.

Why is cross-pollination beneficial?

 

Answer:

Introduces genetic variation.

Increases adaptability to changing environments.

What are the agents of pollination?

 

Answer:

Wind-pollination

(e.g., grasses)

Water-pollination

(e.g., Hydrilla)

Insect-pollination

(e.g., sunflower, rose)

How do seeds disperse to different locations?

 

Answer:

By wind

(Light seeds like dandelion).

By water

(Coconut floats in water).

By animals

(Sticky seeds attach to fur).

 

What is puberty?

 

Answer:

Puberty is the stage in life when humans develop secondary sexual characteristics and become capable of reproduction.

 

Name the male and female reproductive organs in humans.

 

Answer:

Male:

Testes, penis, vas deferens

Female:

Ovaries, fallopian tubes, uterus

What is the role of the testes?

 

Answer:

Produce

sperm cells

.

Secrete

testosterone hormone

.

What is the function of the fallopian tubes?

 

Answer:

Carry the egg from ovary to uterus.

Site of

fertilization

.

What happens if fertilization does not occur?

 

Answer:

The unfertilized egg and uterine lining are shed during

menstruation

.

What is implantation?

 

Answer:

It is the attachment of the fertilized egg (zygote) to the uterus wall.

What is placenta? What is its function?

 

Answer:

Placenta is an organ that connects the mother and

fetus

for

nutrient and oxygen exchange

.

Why are testes located outside the abdominal cavity?

 

Answer:

To maintain a lower temperature for

sperm production

.

What are STDs? Give examples.

 

Answer:

Sexually transmitted diseases.

Examples:

AIDS, Syphilis,

Gonorrhea

.

What are contraceptive methods? Give examples.

 

Answer:

Methods to prevent pregnancy.

Examples:

Condoms, oral pills, copper-T, sterilization

.