Tag: asexual and sexual reproduction in plants

Questions Related to asexual and sexual reproduction in plants

In ovule, functional megaspore develops into ______________.

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

  1. Pollen mother cell-PMC

  2. Megaspore mother cell-MMC

  3. Embryosac

  4. Both 2 and 3

Show answer
Correct Option: A

From which part of the ovary do seeds and fruit develop?

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

  1. Ovaries; Ovules

  2. Ovules; Ovaries

  3. Ovules; Stamens

  4. Stamens; Ovaries

Show answer
Correct Option: B
Explanation:

The ovule  develops into seed and ovary develops into fruit and seeds are enclosed within the fruit. Both are result of fertilisation in angiosperm plant. 

In ovule, endothelium is

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

  1. Nucellus

  2. Nucellus surrounding embryo sac

  3. Tissue near chalaza

  4. Inner part of integument

Show answer
Correct Option: D
Explanation:
In some plants having unitegmic and tenuinucellate ovules, the nucellus degenerates at an early stage. In such ovules, the innermost layer of the integument becomes specialized to perform the nutritive function of the growing embryo sac. This specialized tissue is called the Endothelium. The endothelium is generally single layered and the cells are radially elongated and have dense cytoplasm. Hence, in the ovule Endothelium is the inner part of the integument.
So, the correct answer is D.

In 82% of angiosperm families, ovule is

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

  1. Anatropous

  2. Orthotropous

  3. Amphitropous

  4. Circinotropous

Show answer
Correct Option: A
Explanation:
In gymnosperms, the ovules lie uncovered on the scales of the cone. In angiosperms, one or more ovules are enclosed by the ovary (the portion of the carpel or female reproductive organ). Each ovule is attached by its base to the stalk (funiculus) that bears it. 
Based on the form and position of the ovule they are classified as orthotropous are simplest and primitive type ovules stand out straight into the cavity of the ovary; campylotropous ovules are at right angles to the funiculus; anatropous are most common type  ovules are directed back toward the funiculus or completely inverted ovule turned back 180 degree on its stalk. Intermediate forms also occur
So, the correct answer is 'Anatropous'

Choose the correct answers from the alternatives given.
The ovule is comparable to

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

  1. megasporangium

  2. microsporangium

  3. megasporophyll

  4. microsporophyll

Show answer
Correct Option: A
Explanation:

In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: The integument(s), forming its outer layer(s), the nucellus (or remnant of the megasporangium), and the female gametophyte (formed from a haploid megaspore) in its centre.

So, the correct option is, 'megasporangium'.

Ovule in which funicle, chalaza and micropyle occur in one vertical plane is _________.

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

  1. Anatropous

  2. Orthotropous

  3. Amphitropous

  4. Campylotropous

Show answer
Correct Option: B
Explanation:

Those ovules in which the funicle, chalaza and micropyle lie in one straight line are called orthotropous ovules. Example, Urticaceae.

A. Anatropous ovules are those that have turned 180$^{o}$ and so the micropyle lies close to the hilum.
B. Orthotropous ovules are those that have funicle, chalaza and micropyle lie in one straight line.
C. Amphitropous ovules are curved and are horseshoe shaped.
D. Campylotropous ovules are curved such that micropyle and hilum do not lie in the straight line.
Hence, the correct answer is 'Orthotropous'.

Starting from the Innermost part, the correct sequence of parts in an ovule are.

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

  1. Egg, nucellus, embryo sac, integument

  2. Egg, embryo sac, nucellus, integument

  3. Embryo sac, nucellus, integument, egg

  4. Egg, integument, embryo sac, nucellus

Show answer
Correct Option: B
Explanation:

Egg cell is inside the embryo sac in the ovule. The embryo sac is further enclosed by the parenchymatous tissue, nucellus, which provides nutrition to developing embryo. Nucellus is ultimately surrounded by integuments.

If spores have 10 chromosomes and 20 picogram DNA then what would be the chromosome number and DNA amount in spore mother cell at the end of S-phase in the life cycle of the same plant?

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

  1. 40 chromosomes and 80 pg DNA

  2. 20 chromosomes and 80 pg DNA

  3. 20 chromosomes and 40 pg DNA

  4. 40 chromosomes and 40 pg DNA

Show answer
Correct Option: B

State whether the following statements are true or false.
Ovules are classified on the basis of the position of micropyle with respect to funicle.

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

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

In seed plants, the ovule ("small egg") is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: The integument(s) form its outer layer(s), the nucellus (or remnant of the megasporangium), and female gametophyte (formed from haploid megaspore) in its centre. Mature ovules i.e. megasporangia in angiosperms are mainly of five types. The principle of classification is based on the position of the micropyle, chalaza and hilum with regard to one another and also to the placenta.

So, the correct option is, 'true'.

Following meiosis in ovules, how many megaspores are formed?

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

  1. Two

  2. Four

  3. Six

  4. Eight

Show answer
Correct Option: B
Explanation:

The ovule is the structure that gives rise to and contains the female reproductive cells. The megaspore is produced inside the nucleus of the ovule. During megasporogenesis, the megasporocyte or megaspore mother cell, undergoes meiosis to produce initially four haploid cells (the megaspores). After megasporogenesis, the megaspore develops into the female gametophyte (the embryo sac) in a process called megasporogenesis

So, the correct answer is 'four'