Biology · Science General

Botany and Plant Science

4,989 Questions

Botany and plant science delve into the biological study of plant life, covering structural anatomy, physiological processes, and reproductive mechanisms. Key topics include inflorescence patterns, root modifications, and seed development, which are vital for biology sections in medical entrance exams. This collection of practice questions helps solidify understanding of complex plant functions.

Plant ReproductionPlant AnatomyRoot ModificationsInflorescence PatternsPlant Morphology

Botany and Plant Science Questions

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

Which is diploid structure?

  1. Pollen grains

  2. Egg

  3. Megaspore

  4. MMC
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
•Pollen grains develop from microspores. Microspores are formed from the microspore mother cell. Microspore mother cell is diploid and undergoes meiosis to produce four haploid microspores which develop to form pollen grains. Hence, pollen grains are haploid.
•Egg is the female gamete present in the embryo sac. Egg cell is haploid and on fusion with male gamete produces a diploid zygote. Hence, egg is haploid.
•Megaspore is formed from the megaspore mother cell. Megaspore mother cell is diploid and undergoes meiosis to produce four haploid megaspores. Hence, megaspore is haploid.
•MMC or Megaspore Mother Cell is a diploid cell which develops in the Nucellus of the ovule. MMC undergoes meiotic division to produce four haploid megaspores out of which, only one remains functional and the other three degenerate.
Hence, only MMC is diploid and rest are haploid structures.
So, the correct answer is D.
Multiple choice botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

The ovule of an angiospherem is technical equivalent to

  1. Megaspore

  2. Megasporangium

  3. Megasporophyll

  4. Megaspore mother cell
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The placentas consists an enlarged basal portion which is called as ovary bearing one or more ovules also called as integumented megasporangium.

So the correct option is 'Megasporangium'.

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

Type of ovule present in Opuntia is

  1. Amphitropous

  2. Campylotropous

  3. Circinotropous

  4. Orthotropous
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
• Amphitropous ovule- The body of ovule gets curved along with the embryo sac in such a way that it becomes horseshoe-shaped. This type of ovule is found in families like Butamaceae, Loganiaceae.
• Campylotropous ovule- This type of ovule is similar to Anatropous ovule but curvature is less than that of anatropous ovule. Campylotropous ovule is found in families like Chenopodiaceae. 
• Circinotropous ovule- In this type of ovule, the length of funiculus becomes increased and it covers the whole ovule. It is found in families like Cactaceae (Opuntia).
• Orthotropous ovule is the simplest and primitive type of ovule. In this type of ovule, micropyle, chalaza and funiculus lie in one vertical plane. Examples , all gymnosperms, Polygonum.
Hence, Opuntia has circinotropous ovule. So, the correct answer is C.
Multiple choice botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

In ovule, cuticle is present over

  1. Outer part of integument

  2. Outer part of nucellus

  3. Surface of both nucellus and integuments

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The cuticle is a waxy substance which fills the space between the Nucellus and inner integument and between the outer and inner integuments of the ovule. Both the integuments are covered with a layer of cuticle.
Hence, the cuticle is present over the outer part of integument.
So, the correct answer is A.
Multiple choice botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

Which one produces callose for breaking plasmodesmal connections among microspore mother cell?

  1. Microspore mother cells

  2. Sporogenous cells

  3. Tapetum

  4. Middle layers
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The process of formation of microspores from spore mother cells (SMC) or Microspore mother cell is called microsporogenesis. Very important changes occur in the Tapetum and locule of the anther during microsporogenesis. In the beginning, when the locule is preparing for microsporogenesis, there are plasmodesmatal connections between Tapetal and Tapetal cells, tapetal and SMC and between SMC and SMC. Very small molecules can pass through these connections. Towards the end of zygotene-pachytene stage of prophase I of meiosis, callose layer starts to get depositing around each SMC and the plasmodesmatal connections are cut off. This callose is contributed by the dictyosomes present in the peripheral cytoplasm of the microspore mother cell.
Hence, Microspore mother cells produces callose for breaking the plasmodesmatal connections among microspore mother cells.
So, the correct answer is A.
Multiple choice botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

Ovules of Capsella and Pisum sativum are

  1. Orthotropous

  2. Anatropous

  3. Amphitropous

  4. Campylotropus
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

• Orthotropous ovule - The simplest and primitive type of ovule. In this type of ovule, micropyle, chalaza, and funiculus lie in one vertical plane. Examples: all gymnosperms, Polygonum.

• Anatropous ovule - The most common type of ovules which occurs in more than 80% of angiosperm families. The body of ovule is rotated by 180° and micropyle comes near to the funiculus. Chalaza and micropyle lie in the straight line but hilum is at 90° to the micropyle.
• Amphitropous ovule - The body of ovule gets curved along with the embryo sac in such a way that it becomes horseshoe-shaped. This type of ovule is found in families like Butamaceae, Loganiaceae.
• Campylotropous ovule - This type of ovule is similar to Anatropous ovule but the curvature is less than that of an anatropous ovule. The campylotropous ovule is found in family Chenopodiaceae and in Pisum and Capsella.
So, the correct answer is D.

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

Tetrad of megaspores is generally

  1. Tetrahedral

  2. Linear

  3. Decussate

  4. Isobilateral
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Megaspore mother cell undergoes meiosis to form four haploid megaspores. These megaspores are arranged in the form of a linear tetrad. The megaspore mother cell undergoes first meiotic division and a transverse wall is laid down resulting in the formation of a dyad. The two cells of the dyad similar divides transversely resulting in the formation of a linear tetrad. Tetrahedral, decussate, and isobilateral tetrads are found in case of microspores i.e. such tetrads are formed during microsporogenesis. Hence, tetrad of megaspores is generally linear.
So, the correct answer is B.
Multiple choice botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

Ovule of Opuntia is

  1. Campylotropus

  2. Amphitropous

  3. Circinotropous

  4. Hemitropous
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
•Campylotropous ovule- This type of ovule is similar to Anatropous ovule but curvature is less than that of anatropous ovule. Micropyle is near to the funiculus. Chalaza and micropyle lie in the straight line but hilum is at 90° to micropyle. Campylotropous ovule is found in family Chenopodiaceae and in Pisum and Capsella.
•Amphitropous ovule- The body of ovule gets curved along with the embryo sac in such a way that it becomes horseshoe-shaped. This type of ovule is found in families like Butamaceae, Loganiaceae.
•Circinotropous ovule- In this type of ovule, the length of funiculus becomes increased and it covers the whole ovule. It is found in families like Cactaceae (Opuntia).
•Hemianatropous ovule- The body of ovule is turned through 90° and micropyle and chalaza lie in a straight line but funiculus is at right angle or 90° with both these two. E.g. Ranunculaceae.
Since Opuntia has Circinotropous ovule.
So, the correct answer is C.
Multiple choice botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

Which of the following pairs of terms is a correct match?

  1. Ovule-egg

  2. Pollen grain-sperm

  3. Seed-zygote

  4. Embryo sac-female gametophyte

  5. All of the above
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Ovule- The ovule is the structure that gives rise to and contains the female reproductive cells. The ovule is located inside the portion of the flower called the gynoecium.

Pollen grain- A pollen grain is a microscopic body that contains the male reproductive cell of a plant. Pollen grains represent the male portion of the reproductive process in plants and trees.
Seed- A seed is an embryonic plant enclosed in a protective outer covering. The embryo is developed from the zygote and the seed coat from the integuments of the ovule.
Embryo sac- the female gametophyte of a seed plant consisting of a thin-walled sac within the nucellus that contains the egg nucleus and other nuclei which give rise to endosperm on fertilization.
So the correct option is 'all of these'

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

In ovule, functional megaspore develops into ______________.

  1. Pollen mother cell-PMC

  2. Megaspore mother cell-MMC

  3. Embryosac

  4. Both 2 and 3
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In flowering plants, the functional megaspore undergoes mitotic divisions to form the female gametophyte, which is known as the embryo sac. The megaspore mother cell and pollen mother cell are earlier precursor stages, not the developmental product of the functional megaspore.

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

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

  1. Ovaries; Ovules

  2. Ovules; Ovaries

  3. Ovules; Stamens

  4. Stamens; Ovaries
Reveal answer Fill a bubble to check yourself
B Correct answer
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. 

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

In 82% of angiosperm families, ovule is

  1. Anatropous

  2. Orthotropous

  3. Amphitropous

  4. Circinotropous
Reveal answer Fill a bubble to check yourself
A Correct answer
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'
Multiple choice botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

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

  1. megasporangium

  2. microsporangium

  3. megasporophyll

  4. microsporophyll
Reveal answer Fill a bubble to check yourself
A Correct answer
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'.

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

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

  1. Anatropous

  2. Orthotropous

  3. Amphitropous

  4. Campylotropous
Reveal answer Fill a bubble to check yourself
B Correct answer
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'.

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

Following meiosis in ovules, how many megaspores are formed?

  1. Two

  2. Four

  3. Six

  4. Eight
Reveal answer Fill a bubble to check yourself
B Correct answer
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'