Plant Kingdom Question 604
Assertion : The interval between pollination and fertilization is about 4 months in Cycas. Reason : Cycas show retention of non-swimming sperm.
Options:
A) If both the assertion and the reason are true and the reason is a correct explanation of the assertion
B) If both the assertion and reason are true but the reason is not a correct explanation of the assertion
C) If the assertion is true but the reason is false
D) If both the assertion and reason are false
Show Answer
Answer:
Correct Answer: B
Solution:
Soon after pollination, the pollen tube elongates and it grows downward through the nucellus.
It eats its way downwards gradually digesting and breaking down the tissues of the pollen chamber.
The pollen tube then remains a cavity which is partly a pollen chamber and partly an archegonial chamber until the archegonia mature.
Due to these several series of processes, the time interval of pollination and fertilization is four months.
The sperm of Cycas are multiciliate and motile.
This retention of swimming sperm in Cycas is a character inherited from distant algal ancestors.
BETA
