Tag: modes of reproduction

Questions Related to modes of reproduction

How many meiosis are required for the formation of 100 grains of wheat.

botany modes of reproduction structure of male and female reproductive structures structure of ovule gynoecium

  1. 100

  2. 200

  3. 150

  4. 125

Show answer
Correct Option: D
Explanation:
In plants, four male gametes are produced by a single microspore via meiosis. So, after 25 divisions, 100 male gametes will be produced. Also, one female gamete is produced after a single meiotic division. Hence, 100 eggs will be produced in 100 divisions. Hence, a total of 125 meiotic divisions are required for the formation of 100 wheat grains.
So, the correct answer is '125'.

Choose the correct answers from the alternatives given.
After fertilization, fruit is derived from

botany modes of reproduction structure of male and female reproductive structures structure of ovule gynoecium

  1. endosperm

  2. ovule

  3. ovary

  4. microsporophyll

Show answer
Correct Option: C
Explanation:

Fruits are produced only by flowering plants (angiosperms). Following pollination of the flower, the fertilized ovules develop into seeds while the surrounding ovary wall forms the fruit tissue, or pericarp.

So, the correct option is 'ovary'.

Which of the following parts of the flower develops to become a fruit?

botany modes of reproduction structure of male and female reproductive structures structure of ovule gynoecium

  1. Stigma

  2. Style

  3. Ovary

  4. Stamen

Show answer
Correct Option: C
Explanation:
A fertilized flower gives rise to a fruit. A fruit is defined as a ripened ovary. It protects the seeds formed from the ovule. The pericarp is the fruit wall that develops from the ovary wall. A fleshy fruit is made up of three layers- 
1) Exocarp which is the outer layer or skin.
2) Mesocarp which is the middle layer that is fleshy.
3) Endocarp which is the inner layer surrounding the seed.
Thus the correct answer is option C.

A seed contains

botany modes of reproduction structure of male and female reproductive structures structure of ovule gynoecium

  1. A seed coat

  2. An embryo

  3. Stored food

  4. All of these

Show answer
Correct Option: D
Explanation:

A seed is an embryonic plant enclosed in a protective outer covering. Seeds are the product of the ripened ovule, after fertilization by pollen and some growth within the mother plant. The embryo is developed from the zygote and the seed coat from the integuments of the ovule. Seed has endosperm that stores food to provide nutrition to the embryo. The formation of the seed is part of the process of reproduction in seed plants

So, the correct answer is 'all of these'

In the plant part having two generations is

botany modes of reproduction structure of male and female reproductive structures structure of ovule gynoecium

  1. embryo

  2. unfertilized ovule

  3. germinated pollen grain

  4. seed

Show answer
Correct Option: D
Explanation:

Plant part having two ages, one inside the other is seed. Seed is a develop ovule comprising of the embryonic plant along with the putaway nourishment material.

So, the correct option is 'seed'.

Active form of phytochrome for seed germination is

botany modes of reproduction structure of male and female reproductive structures structure of ovule gynoecium

  1. P$ _{r}$-form

  2. P$ _{fr}$-form

  3. Both of A and B

  4. None of the above

Show answer
Correct Option: B
Explanation:

The main photoreceptor for photoperiodism and many other light-initiated plant responses is phytochrome, a family of about five blue-green pigment proteins, each of which is coded for by a different gene. Phytochrome is involved in the light requirement that some seeds have for germination. Seeds with a light requirement must be exposed to light containing red wavelengths. Exposure to red light converts $P _r$ to $P _{fr}$ and germination occurs. When $P _{fr}$ absorbs far-red light it is converted back to $P _r$. Hence, red light makes $P _{fr}$, far-red light makes $P _r$. In plants at least $P _{fr}$ is the physiologically active or "signalling" state.

Choose the correct answers from the alternatives given.
.After fertilization the seed coats develop from

botany modes of reproduction structure of male and female reproductive structures structure of ovule gynoecium

  1. integuments

  2. chalaza

  3. nucellus

  4. embryo sac

Show answer
Correct Option: A
Explanation:

 Seeds are the product of the ripened ovule, after fertilization by pollen and some growth within the mother plant. The embryo is developed from the zygote and the seed coat from the integuments of the ovule. 

So, the correct option is, 'integuments'.

Which of the following structures is unique to the seed of a monocot?

botany modes of reproduction structure of male and female reproductive structures structure of ovule gynoecium

  1. Coleoptiles

  2. Radicle

  3. Seed coat

  4. Endosperm

Show answer
Correct Option: A
Explanation:
A monocotyledonous seed is the one which has a thick seed coat. Inside the seed coat are the endosperm and the embryo. Endosperm is the nourishing tissue which provides food for the growing embryo. In monocots, single cotyledon present is called as scutellum which absorbs nourishment from the endosperm and transfers to the growing embryo. The embryo has two structures namely, radicle and plumule. Radicle, the future root is protected by a sheath called as coleorhiza and plumule, the future shoot is protected by a sheath called as coleoptile. 
So the correct option is 'coleoptiles'.

The ovary ripens to form fruit.

botany modes of reproduction structure of male and female reproductive structures structure of ovule gynoecium

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

As the ovules develop into seeds, the ovary begins to ripen and the ovary wall becomes fleshy and forms a hard outer covering to protect the fruit. Fruit is also called as ripened ovary. So the given statement is true.

So, the correct option is 'True'.

Testa of seed is produced from

botany modes of reproduction structure of male and female reproductive structures structure of ovule gynoecium

  1. ovary wall

  2. hilum

  3. outer integument of ovule

  4. funicle

Show answer
Correct Option: C
Explanation:

A seed develops from an ovule after fertilisation. It consists of a tough coat called testa enclosing an embryo which is made up of plumule, radicle or cotyledons. It is produced from an outer integument of the ovule. 

So, the correct option is 'Option C'.