Biology · Science General

Botany and Plant Science

5,038 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 male & female gametophytes: structure and development pollen grain androecium male gametophyte

Male gametophyte in angiosperms produces

  1. Two sperms and a vegetative cell

  2. Single sperm and a vegetative cell

  3. Single sperm and two vegetative cells

  4. Three sperms
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
In angiosperms the pollen grain is the male gametophyte. It consists of 2 generative nuclei/cell and 1 vegetative nucleus/cell
So, the correct answer is 'Two sperms and a vegetative cell'
Multiple choice botany male & female gametophytes: structure and development pollen grain androecium male gametophyte

Germ pores in the pollen grains are regions.

  1. That can withstand high temperature, strong acids and alkalies

  2. Through which sperms are released into the female gametophyte

  3. Which are made of lignin and suberin

  4. Which lack sporopollenin
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Germ pores are specific areas on the pollen grain wall where the exine is thin or absent, meaning they lack the resistant sporopollenin, allowing the pollen tube to emerge.

Multiple choice botany male & female gametophytes: structure and development pollen grain androecium male gametophyte

Consider the following statements with respect to pollen grains.
(a) Exine is thin, continuous layer made up of cellulose and pectin
(b) Hard outer layer called exine is made of sporopollenin
(c) Sporopollenin is present in germ pores
(d) Exine exhibits a fascinating array of patterns and designs. Of the statements.

  1. a and b alone are correct

  2. a and c alone are correct

  3. b and d alone are correct

  4. b and c alone are correct
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
•Exine is a thick layer made up of sporopollenin. The exine is discontinuous in some regions where sporopollenin is absent. These regions mark the germ pores. Hence statement (a) is incorrect.
•Hard outer layer of Exine is made up of sporopollenin which is one of the most resistant known biological material. Hence statement (b) is correct.
•Sporopollenin is absent at the site of germ pores. Hence statement (c) is incorrect.
•Exine shows different patterns or sculptures due to Tectum and Bacula layers. Hence statement (d) is correct.
Therefore, statements (b) and (d) are correct.
So, the correct answer is C.
Multiple choice botany male & female gametophytes: structure and development pollen grain androecium male gametophyte

Choose the correct options for statements P, Q, R in relevance to grass.
Statement P: Flowers possess attractive colour and fragrance.
Statement Q: Pollen grains are small, dry and light in weight.
Statement R: Grass is air pollinated plant.

  1. Both P and Q are true, R is correct explanation of Q

  2. P is true and Q is false, R is correct explanation of P

  3. P is false and Q is true, R is correct explanation of Q

  4. Both P and Q are false, R has no relation with P and Q
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Grass is wind-pollinated (anemophilous). Statement P is false because grass flowers are not colorful or fragrant. Statement Q is true because pollen must be light and dry for wind transport. R is true and explains why Q is necessary.

Multiple choice botany male & female gametophytes: structure and development pollen grain androecium male gametophyte

Discontinuous layers in the wall of pollen grain are

  1. Absent

  2. Foot layer

  3. Baculate layer

  4. Baculate layer and tectum
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Pollen wall comprises of two layers: outer layer exine and inner layer intine. The exine is chemically differentiated into two layers: an outer layer called "ektexine" and an inner layer called "endexine". Ektexine is further comprised of tectum, bacula and a foot layer. Above the foot layer is present a layer of rod like elements called columella or bacula, which is covered over by a roof like layer called the tectum.
The Tectum and Bacula layers form different patterns on the pollen grains as they are discontinuous at some regions and thus various types of sculptured patterns are seen in pollen grains.
So, the correct answer is D.

Multiple choice botany male & female gametophytes: structure and development pollen grain androecium male gametophyte

Pollen tube is covered by

  1. Exine only

  2. Plasmalemma only

  3. Intine only

  4. Exine and intine
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Pollen tube emerge out from the germ pore. Exine is very thin at the site of germ pores. The pollen grain gets hydrated at the time of germination. There occurs swelling in the outer pectic layer of intine that leads to rupture of Exine. Thus, its intine that comes out in the form of pollen tube.
Hence, pollen tube is covered by Intine.
So, the correct answer is C.

Multiple choice botany male & female gametophytes: structure and development pollen grain androecium male gametophyte

Choose the correct answers from the alternatives given.
Which of the following is mismatched?

  1. Polle grain-microgametophyte

  2. Ovule-megagametophyte

  3. Seed-immature sporophyte

  4. Pollen tube-spores
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Pollen tubes are the structure that helps in the entry of the male nuclei into the ovule and then the fertilization takes place. Pollen tube does not form spores. It is just a medium that carries the male gametes.

So, the correct option is 'Pollen tube-spores'

Multiple choice botany male & female gametophytes: structure and development pollen grain androecium male gametophyte

Embryo sac is to ovule as _________ is to an anther.

  1. Stamen

  2. Filament

  3. Pollen grain

  4. Androecium
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A typical carpel consists of ovary which can have many ovules. Each ovule has an embryo sac, which in turn has a single egg cell. Similarly, in majority of angiosperms each stamen consists of a bilobed anther, which in turn has two pollen sacs in each lobe, consisting of pollen grains.

Multiple choice botany male & female gametophytes: structure and development pollen grain androecium male gametophyte

A pollen tube of a flowering plant is the

  1. Male gamete

  2. Female gamete

  3. Germinating spore

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

A pollen tube is a tubular structure produced by the male gametophyte of seed plants when it germinates. They act as conduits to transport the male gamete cells from the pollen grain—either from the stigma (in flowering plants) to the ovules at the base of the pistil or directly through ovule tissue in some gymnosperms. Pollen tube formation is important for sexual reproduction to occur in seed plants. Pollen tubes are unique to plants and their structure had evolved over plant history.

So the correct option is 'male gametophyte'.

Multiple choice botany male & female gametophytes: structure and development pollen grain androecium male gametophyte

Consider the following statements.
(i) Polyspermy may bring about fertilisation of egg by more than one male nucleus or the supernumerary sperms may fertilise other components of embryo sac such as synergids or antipodals.
(ii) In angiosperms, pollen tube is normally an unbranched structure which usually persists after fertilisation.
(iii) Intine is the inner, pectocellulosic layer of pollen grain wall which is destroyed during acetolysis.
(iv) Exine layer of pollen grain comprises of an outer non-sculptured layer sexine and an inner sculptured layer tectum.
Which of the following combinations of given statements is correct?

  1. (i) and (iv)

  2. (i) and (iii)

  3. (ii) and (iii)

  4. (ii) and (iv)
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Polyspermy refers to a situation where more than two sperms are released in an embryo sac. This may result because of the formation of more than two sperms in a pollen tube or due to the penetration of an embryo sac by more than one pollen tube. In angiosperms, the pollen tube is normally an unbranched structure which collapses soon after fertilization, the pollen tube may persist for as long as three weeks. Intine is the inner, more or less uniform, pectocellulosic layer of pollen grain wall, which is destroyed during acetolysis. Morphologically, the exine is divisible into two distinct layers: (i) an outer sculptured layer called sexine, and (ii) an inner non-sculptured layer, nexine. The sexine further comprises an internal layer of upright rod-like elements, the columellae(bacula) covered over by a roof-like layer, the tectum. The exine is, thus, typically33-layered consisting of tectum, columella, and nexine. The tectum may be smooth or have various types of processes.

So, the correct answer is '(i) and (iii)'.

Multiple choice botany male & female gametophytes: structure and development pollen grain androecium male gametophyte

Choose the correct answers from the alternatives given.
A pollen grain is best defined as a

  1. male gamete

  2. microspore mother cell

  3. partially developed male gametophyte

  4. partially developed embryo
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Each pollen grain is a minute body, of varying shape and structure, formed in the male structures of seed-bearing plants and transported by various means (wind, water, insects, etc.) to the female structures, where fertilization occurs. In angiosperms, pollen is produced by the anthers of the stamens in flowers.

So, the correct option is, 'partially develop male gametophyte'

Multiple choice botany male & female gametophytes: structure and development pollen grain androecium male gametophyte

Ubisch bodies found in tapetal cell helps in the formation of 

  1. Pollenkitt and pollinia

  2. Exine

  3. Intine and pollenkitt

  4. none of above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ubisch bodies found in tapetal cells help in pollen formation by participating in the external thickening of exine. They occur during spore wall formation and migrate to the cell cavity, where they are coated with sporopollenin and are released into the anther cavity. 

So, the correct option is 'Exine'.