Multiple Choice QuestionsDuring formation of which of the following free nuclear division occurs?
Flower
Endosperm
Gametes
Fruit
Assertion : The megaspore mother cell undergoes mitosis to produce four megaspores.
Reason : Megaspore mother cells and the megaspores are both haploid.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both the assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both the assertion and reason are false.
If there are 4 microspore mother cells in an anther, what will be the number of pollen grains?
4
8
12
16
Pollen grains are able to withstand extremes of temperature and dessication because their exine is composed of
cutin
suberin
sporopollenin
callose
C.
sporopollenin
Exine is outer layer of pollen grain which is acetolysis resistant layer. It is also resistant to physical and biological degradation. Because of this property of exine, pollen grains are found well preserved for long periods in fossil deposits.
Cutin is a waxy repellant substance in the cuticle of plants, consisting of higly polymerized esters of fatty acids.
Suberin is an inert impermeable waxy substance present in the cell walls of corky tissues.
Callose is a plant polysaccharide. It plays an important in plant development.
When the filament runs throughout the length of anther, it is called
adnate
dorsi fixed
versatile
syngenesious
Assertion : The two cotyledons in the seed are often referred to as the embryonic leaves.
Reason : The embryo contains radicle and plumule.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both the assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both the assertion and reason are false.
Assertion : Many visitors to the hills suffer from skin and respiratory allergy problem.
Reason : Conifer trees produce a large quantity of wind-borne pollen grains.
If both Assertion and Reason are true and the reason is the correct explanation of the assertion
If both Assertion and Reason are true but the reason is not the correct explanation of the assertion
If Assertion is true statement but Reason is false
If both Assertion and Reason are false statements
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