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501 questions in this collection · Page 1 of 51
Question 1 of 501
📘 CLASS XII
Sexual Reproduction In Flowering Plants
The proximal end of the filament of a stamen is attached to which part of the flower?
A typical stamen consists of a long and slender stalk called the filament. The proximal end of the filament is attached to the thalamus or the petal of the flower.
Question 2 of 501
📘 CLASS XII
Sexual Reproduction In Flowering Plants
Which of the following best describes the structure of a typical angiosperm anther?
A typical angiosperm anther is bilobed with each lobe having two theca, meaning they are dithecous. Often a longitudinal groove runs lengthwise separating the theca.
Question 3 of 501
📘 CLASS XII
Sexual Reproduction In Flowering Plants
Which layer of the microsporangium wall performs the function of nourishment for developing pollen grains?
The innermost wall layer is the tapetum. It nourishes the developing pollen grains. Cells of the tapetum possess dense cytoplasm and generally have more than one nucleus.
Question 4 of 501
📘 CLASS XII
Sexual Reproduction In Flowering Plants
The process of formation of microspores from a pollen mother cell (PMC) is termed as:
The process of formation of microspores from a pollen mother cell (PMC) through meiosis is called microsporogenesis.
Question 5 of 501
📘 CLASS XII
Sexual Reproduction In Flowering Plants
The hard outer layer of the pollen grain, the exine, is composed of which highly resistant material?
The hard outer layer called the exine is made up of sporopollenin which is one of the most resistant organic material known. It can withstand high temperatures and strong acids and alkali.
Question 6 of 501
📘 CLASS XII
Sexual Reproduction In Flowering Plants
What is the specific area on the pollen grain exine called where sporopollenin is absent?
Pollen grain exine has prominent apertures called germ pores where sporopollenin is absent. Pollen tubes exit through these pores during germination.
Question 7 of 501
📘 CLASS XII
Sexual Reproduction In Flowering Plants
In over 60 per cent of angiosperms, pollen grains are shed at which stage?
In over 60 per cent of angiosperms, pollen grains are shed at the 2-celled stage, containing a vegetative cell and a generative cell.
Question 8 of 501
📘 CLASS XII
Sexual Reproduction In Flowering Plants
Which plant species introduced as a contaminant in imported wheat has become ubiquitous in India and causes pollen allergy?
Parthenium or carrot grass that came into India as a contaminant with imported wheat has become ubiquitous in occurrence and causes pollen allergy.
Question 9 of 501
📘 CLASS XII
Sexual Reproduction In Flowering Plants
At what temperature are pollen grains stored in liquid nitrogen for pollen banks?
It is possible to store pollen grains of a large number of species for years in liquid nitrogen (-196 degrees C). Such stored pollen can be used as pollen banks.
Question 10 of 501
📘 CLASS XII
Sexual Reproduction In Flowering Plants
Which of the following represents the basal part of the ovule?
Opposite the micropylar end is the chalaza, representing the basal part of the ovule.