Question

8) What is the difference between cross- and self-fertilization? A) In cross-fertilization the pollen from one plant is used to fertilize the egg from the same plant. (B) In cross-fertilization insects are used to pollinate the plants, whereas in self-fertilization the investigator pollinates the plants. C) In self-fertilization the pollen from one plant is used to fertilize the egg from another plant. D) In cross-fertilization the pollen from one plant is used to fertilize the egg of another plant.

Answer 1

Let me clear the differences between self and cross pollination:(Note the words in italics).

SELF POLLINATION	CROSS POLLINATION
i.It is the transfer of pollen from anther to stigma of same flower or another flower on same plant .	i.It is the transfer of pollen from anther of one flower to stigma of another flower borne on different plant.
ii.It does not require an external agent.	ii.It does require an external agent example wind,water,insects..
iii.Both anther and stigma mature at same time.	iii.Both anther and stigma mature at different time.
iv.It can occur even when flower is closed.	iv.It occurs when the flower is open.
v.It does not produce variation.	v.It produces variation.

Option A and C are not correct as per the table.

Option D does not tell about self pollination though it is correct about cross pollination .

Option B states a major difference between self and cross pollination in terms of the pollinating agents.

Hence the correct answer is option B