Tag: structure of ovule

Questions Related to structure of ovule

Select the correct match.

   List I    List II
 A  Endothecium  1  Nutritive layer
 B  Tapetum  2  Single flower
 C  Tulip  3  Floral organs are borne
 D  Receptacle  4  Middle layer of anther
botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

  1. A- 4, B- 1, C- 2, D- 3

  2. A- 1, B- 4, C- 3, D- 2

  3. A- 3, B- 4, C-2, D- 1

  4. A- 2, B- 3, C- 4, D- 1 

Show answer
Correct Option: A
Explanation:

Endothecium is defined as the lining of the inner cavity of the anther. It is present as a middle layer. 

Tapetum is the nutritive layer present. It provides the function of providing nourishment for the growth. It gets extinct by the time pollen develops. 
Tulip is a flower, which belongs to the family of Liliaceae. 75 wild species are currently accepted. It is a single flower. T
he receptacle is the thickened part of a stem from which the flower organs grow. In some accessory fruits, like pome and strawberry, the receptacle gives rise to the edible part of the fruit.
So, the correct answer is option A.

The cotyledon in monocot plant is one and

botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

  1. Lateral

  2. Terminal

  3. Basal

  4. Vertical

Show answer
Correct Option: B

What is the number of chromosomes in aleurone layer if 10 number of chromosomes are found in megaspore mother cell?

botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

  1. 10

  2. 20

  3. 15

  4. None of the above

Show answer
Correct Option: C
Explanation:

If chromosomes of megaspore mother cell are 10; it ensures that the diploid number is 10. 2n = 10. Therefore, n = 5. Aleurone layer will be triploid in nature. Thus, the number of chromosomes in aleurone layer = 15.

The root cell of wheat plant has 42 chromosomes. What would be the number of chromosomes in the synergid cells?

botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

  1. 7

  2. 14

  3. 21

  4. 28

Show answer
Correct Option: C
Explanation:

The pollen tube ultimately enters an ovule through the micropyle and penetrates one of the sterile cells on either side of the egg ( synergids). These synergids begin to degenerate immediately after pollination. 
Synergids are haploid in nature. Thus, if root cell has 2n = 42, synergids will have n = 21.

The point of attachment of funicle with chalazal end is called as 

botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

  1. Placenta

  2. Integument

  3. Nucellus

  4. Hilum

Show answer
Correct Option: D
Explanation:

The hilum is the point of attachment of funicle with the chalazal end. It is the point where ovule attaches to the base. It is generally present as an eye of the seed as it is present as a scar.

Assertion : Most common type of ovule is anatropous.

Reason : Anatropous ovule is horse-shoe shaped.

botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

  1. Both assertion and reason are true and reason is a correct explanation of the assertion.

  2. Both assertion and reason are true but reason is not a correct explanation of the assertion.

  3. Assertion is true but Reason is false

  4. Both Assertion and Reason are false

  5. Assertion is false but Reason is true

Show answer
Correct Option: C
Explanation:

The ovules where micropyle come to lie close to the funiculus due to unilateral growth of the ovule are called anatropous. This is the most common type of ovule in angiosperms where the curvature of the ovule also affects the nucellus so that the later becomes horse shoe-shaped. The ovule is called amphitropous.

Assertion: In hemianatropous ovule, the funicle lies parallel to body of ovule.

Reason: Here, body of ovule has rotated by $90^{o}$.

botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

  1. Both assertion and reason are true and reason is a correct explanation of the assertion.

  2. Both assertion and reason are true but reason is not a correct explanation of the assertion.

  3. Assertion is true but Reason is false

  4. Both Assertion and Reason are false

  5. Assertion is false but Reason is true

Show answer
Correct Option: E
Explanation:

When funicle lies at right angle to body of ovule and micropyle, the ovule is called hemianatropous or body of ovule has rotated by $90^{o}$.

The megasporangium of the angiosperms on fertilization gives rise to

botany plants: structure and function structure of male and female reproductive structures structure of ovule gynoecium

  1. A fruit

  2. Seed

  3. An embryo

  4. Cotyledons

Show answer
Correct Option: B
Explanation:

The nucellus is a part of the inner structure of the ovule, forming a layer of diploid (sporophytic) cells inside the integuments. It is structurally and functionally equivalent to the megasporangium. In some plants, the diploid tissue of the nucellus gives rise to a seed through a mechanism of asexual reproduction called nucellar embryony.

So, the correct answer is 'seed'

Ovule is called

botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

  1. Megasporangium

  2. Microsporangium

  3. Integumented microsporangium

  4. Integumented megasporagium

Show answer
Correct Option: D

What would be the number of chromosomes in the cell of the aleurone layer in a plant species with 8 chromosomes in its synergids?

botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

  1. 32

  2. 8

  3. 16

  4. 24

Show answer
Correct Option: D
Explanation:

Synergid is one of two small, short-lived nuclei lying near the egg in the mature embryo sac of a flowering plant. The synergids are part of the egg apparatus and are thought to help the pollen nucleus reach the egg cell for fertilization. 

The aleurone layer is the outermost layer of the endosperm, followed by the inner starchy endosperm. the cells of the aleurone layer is a triploid. 
If the synergids contain chromosomes the number of chromosomes in the aleurone layer would be since the aleurone layer is a triploid. 
 So the answer is '24'.