Multiple Choice QuestionsAssertion: In some species of asteraceae and poaceae seeds are formed without fertilization.
Reason: Formation of fruit without fertilization is called parthenocarpy.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false.
Even after killing the generative cell with a laser beam, the pollen grain of a flowering plant germinates and produces normal pollen tube because
laser beam stimulates pollen germination and pollen tube growth
the laser beam does not damage the region from which pollen tube emerges
the contents of killed generative cell permits germination and pollen tube growth
the vegetative cell has not been damaged
Assertion : Protandry and protogyny ensures cross fertilization.
Reason : Cross fertilization introduces variation in progeny.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
B.
If both assertion and reason are true but reason is not the correct explanation of assertion
In some lower animals, the organs of both the sexes are found in the same individual. Hence, they are called bisexual or monoecious animals or hermaphrodites. In these animals, testes and ovaries do not mature simultaneously.
For example in earthworm, testes mature earlier, while in others, e.g., sea-squirt, ovaries mature earlier. These conditions are respectively called protandry and protogyny. They ensure cross fertilization.
Cross fertilization is a process in which gametes derived from different individuals are united to form zygote. It involves the mixing of two different genetic materials. This is better than self-fertilization as it introduces variation by combining traits of two individuals.
Assertion : Pollen mother cells (PMCs) are the first male gametophytic cells.
Reason : Each PMC gives rise to two pollens.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
Which one of the following pairs of plant structures has haploid number of chromosomes
Nucellus and antipodal cells
Egg nucleus and secondary nucleus
Megaspore mother cell and antipodal cells
Egg cell and antipodal cells
Assertion : Emasculation prevents self- pollination in flowers.
Reason : Emasculation is the removal of anthers from a bisexual flower.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false.
Assertion: Maize is an albuminous seed.
Reason: Endosperm is completely absorbed by its growing embryo
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false.
Apomixis is
formation of seeds by fusion of gametes
formation of seeds without syngamy and meiosis
formation of seeds with syngamy but no meiosis
none of the above
Assertion: Nuclear endosperm is formed by subsequent nuclear division without wall formation.
Reason: Coconut is an example of such endosperm, where the endosperm remains nuclear throughout the development of the fruit
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false.
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