Introduction:
Fertilization is a process in which haploid male gamete (sperm) fuses with the haploid female gamete (egg or ovum) that result in the formation of diploid zygote. The zygote further develops into blastula, gastrula that later results in the formation of an embryo.
Answer to Problem 1U
Correct answer:
“The events which occur immediately after fertilization is egg activation, polyspermy defense, cytoplasm changes”. Therefore, option d. is correct.
Explanation of Solution
Reason for the correct statement:
Before fertilization, the egg remains in an inactive state until the sperm reach the egg and fertilization process takes place. The fusion of sperm with egg membrane trigger in the rush of
Option d. is given as “All of these occur after fertilization”.
As, “after fertilization the events that take place is egg activation, polyspermy defense and cytoplasm changes” is the right answer.
Hence, the option d. is correct.
Reasons for the incorrect statements:
Option a. is given as “Egg activation”.
The fusion of sperm with the egg membrane triggers the reactivation of egg metabolism is an event occur after fertilization. But after fertilization other events like polyspermy defense, cytoplasm change also occurs. So, it is a wrong answer.
Option b. is given as “Polyspermy defense”.
To prevent the polyspermy is an event that occurs after fertilization. But after fertilization other events like egg activation and change in cytoplasmic content also occurs. So, it is a wrong answer.
Option c. is given as “Cytoplasm changes”.
After fertilization, the egg changes its cytoplasmic content to prevent the polyspermy. But other events like egg activation and polyspermy defense also occurs. So, it is a wrong answer.
Hence, options a., b. and c. are incorrect.
The events that occur after fertilization are egg activation, polyspermy defense and cytoplasm changes.
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Chapter 53 Solutions
Biology
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