NCERT Exemplar solutions for Science [English] Class 10 chapter 8 - How do Organisms Reproduce? [Latest edition]

In the list of organisms given below, those that reproduce by the asexual method are

1. banana
2. yeast
3. dog
4. Amoeba 

In a flower, the parts that produce male and female gametes (germ cells) are

Which of the following is the correct sequence of events of sexual reproduction in a flower?

Offspring formed by asexual method of reproduction have greater similarity among themselves because

1. asexual reproduction involves only one parent
2. asexual reproduction does not involve gametes
3. asexual reproduction occurs before sexual reproduction
4. asexual reproduction occurs after sexual reproduction

Characters transmitted from parents to offspring are present in

Characters that are transmitted from parents to offspring during reproduction show

A feature of reproduction that is common to Amoeba, Spirogyra and Yeast is that 

In Spirogyra, asexual reproduction takes place by 

The ability of a cell to divide into several cells during reproduction in Plasmodium is called 

The correct sequence of reproductive stages seen in flowering plants is

The number of chromosomes in parents and offsprings of a particular species undergoing sexual reproduction remain constant due to:

In Rhizopus, tubular thread-like structures bearing sporangia at their tips are called 

Vegetative propagation refers to formation of new plants from

Factors responsible for the rapid spread of bread mould on slices of bread are

1. large number of spores
2. availability of moisture and nutrients in bread
3. presence of tubular branched hyphae
4. formation of round shaped sporangia

Length of pollen tube depends on the distance between

Which of the following statements are true for flowers?

1. Flowers are always bisexual
2. They are the sexual reproductive organs
3. They are produced in all groups of plants
4. After fertilisation they give rise to fruits

Which among the following statements are true for unisexual flowers?

1.  They possess both stamen and pistil
2. They possess either stamen or pistil
3. They exhibit cross pollination
4. Unisexual flowers possessing only stamens cannot produce fruits

Which among the following statements are true for sexual reproduction in flowering plants?

1. It requires two types of gametes
2. Fertilisation is a compulsory event
3. It always results in formation of zygote
4. Offspring formed are clones

In Figure, the parts A, B and C are sequentially

Offspring formed as a result of sexual reproduction exhibit more variations because

Reproduction is essential for living organisms in order to

During adolescence, several changes occur in the human body. Mark one change associated with sexual maturation in boys

In human females, an event that reflects onset of reproductive phase is

In human males, the testes lie in the scrotum, because it helps in the

Which among the following is not the function of testes at puberty?

1. formation of germ cells
2. secretion of testosterone
3. development of placenta
4. secretion of estrogen

The correct sequence of organs in the male reproductive system for transport of sperms is

Which among the following diseases is not sexually transmitted?

Would a Planaria cut vertically into two halves regenerate into two individuals? Complete Figure D and E by indicating the regenerated regions. 

A	B	C	D	E

From the internet, gather information about the chromosome numbers of five animals and five plants. Correlate the number with the size of organism and answer the following questions.

1. Do larger organisms have more number of chromosomes/cells?
2. Can organism with fewer chromosomes reproduce more easily than organisms with more number of chromosomes?
3. More the number of chromosomes/cells greater is the DNA content. Justify.

In tobacco plant, the male gametes have twenty four chromosomes.

What is the number of chromosomes in the female gamete?

What is the number of chromosomes in the zygote?

Give reason for the following:

Fertilization cannot take place in flowers if pollination does not occur.

In the given Figure label the parts and mention their functions

1. Production of egg
2. Site of fertilisation
3. Site of implantation
4. Entry of the sperms

Distinguish between pollination and fertilisation. Mention the site and product of fertilisation in a flower.

Draw a neat, labelled diagram of a pistil showing pollen tube growth and its entry into the ovule.