Tag: asexual and sexual reproduction in plants

Questions Related to asexual and sexual reproduction in plants

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 $90^{o}$.

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'. 

A nutritive inner region of integument is?

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

  1. Amphithecium

  2. Endothecium

  3. Endothelium

  4. Endostomium

Show answer
Correct Option: C
Explanation:
In some plants, which have unitegmic and tenuinucellate ovules, nucellus degenerates at an early stage of ovule development. In such cases, the innermost layer of the integument becomes specialized and forms a tissue around the embryo sac that performs the nutritive function for the embryo sac. This specialized tissue is called the Endothelium. Therefore, a nutritive inner region of the integument is Endothelium.
So, the correct answer is C

The point at which funiculus touches the ovule is

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

  1. Chalaza

  2. Hilum

  3. Raphe

  4. Endothelium

Show answer
Correct Option: B
Explanation:
•Chalaza is portion of the ovule which is opposite to the region of attachment of nucellus, integuments and funiculus.
•Hilum is a structure by which body of ovule is attached to the funiculus. 
•Raphe is a ridge showing the fusion of funiculus with the body of ovule.
•Endothelium is a specialized tissue present around the embryo sac which is formed by the specialization of integuments to perform the nutritive function of nucellus in the ovules in which nucellus degenerates at an early stage.
So, the correct answer is B.

Out of linear tetrad which one is the functional megaspore

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

  1. Micropylar

  2. Any of the middle ones

  3. Chalazal

  4. Any of the four

Show answer
Correct Option: C
Explanation:
Megaspore mother cell undergoes meiosis to form four haploid megaspores which are arranged in a linear tetrad. Out of these four megaspores, only one remains functional that develops into embryo sac or the female gametophyte and the rest three degenerate. The megaspore that remains functional can either be micropylar or chalazal depending upon the species. For example, in Polygonum, chalazal megaspore is functional while in Oenothera, micropylar megaspore is functional. Since Polygonum type embryo sac is the most common type of embryo sac found in Angiosperms, the functional Megaspore is generally the chalazal one. 
So, the correct answer is C.

Orthotropous ovules occur in

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

  1. Pisum sativum

  2. Solanum nigrum

  3. Polygonum

  4. Helianthus

Show answer
Correct Option: C
Explanation:
Orthotropous ovule is the simplest and primitive type of ovule. In this type of ovule, micropyle, chalaza and funiculus lie in one vertical plane. Example of plants with orthotropous ovules are, Polygonum, Piper nigrum, Piper betel and all gymnosperms.
So, the correct answer is C.

A mass of parenchymatous tissue forming the bulk of ovule is

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

  1. Obturator

  2. Female gametophyte

  3. Nucellus

  4. Endosperm

Show answer
Correct Option: C
Explanation:
Obturator is a structure of ovule that is associated with directing the growth of pollen tube towards the micropyle. It may originate either from the placenta or funiculus or even both.
Female gametophyte is the embryo sac. It is a 7-celled structure consisting of egg apparatus (comprising of egg cell and two synergids), a large central cell and three antipodal cells.
Nucellus is the central part of ovule in which embryo sac is present. It is a mass of parenchymatous cells and forms the major part of the ovule. 
Endosperm is the nutritive structure formed from triple fusion that provides nutrition to the developing embryo.
Hence, from all the options given in the question, the mass of parenchymatous cells forming bulk of ovule is nucellus.
So, the correct answer is C.