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What happens when double fertilization occurs?
a. Two zygotes are formed, but only one survives.
b. Two sperm fertilize the egg, forming a triploid zygote.
c. One sperm fertilizes the egg, while another sperm fuses with the polar nuclei.
d. One sperm fertilizes the egg, while two other sperm fuse with a polar nucleus.
Introduction:
Double fertilization is a complex fertilization that occurs in the flowering plants (angiosperms). This gives rise to endosperm apart from the zygote.
Answer to Problem 2TYK
Correct answer:
Double fertilization is a mechanism where one sperm fertilizes the egg and another sperm fuses with the polar nuclei.
Explanation of Solution
Explanation/Justification for the correct answer:
Option (c) is given that double fertilization occurs when one sperm fuses with an egg and another sperm fuses with the polar nuclei. One of the sperm fuses with the egg cell and forms a diploid zygote, while the other sperm fuses with the two polar nuclei and forms a triploid cell. Hence, Option (c) is correct.
Explanation for incorrect answers:
Option (a) is given that double fertilization occurs when two zygotes are formed, but only one survives. Only one zygote is formed in double fertilization. So, it is a wrong answer.
Option (b) is given that double fertilization occurs when two sperms fertilize the egg, forming a triploid zygote. One of the sperm fertilizes the egg and other one fuses with the two polar nuclei. Both of them do not fertilize the egg. So, it is a wrong answer.
Option (d) is given that double fertilization occurs when one sperm fertilizes the egg, while two other sperm fuse with a polar nucleus. This process does not involve three sperm. Only two sperm are required: one sperm fuses with the egg and another one with the polar nuclei. So, it is a wrong answer.
Hence, options (a), (b), and (d) are incorrect.
Thus, double fertilization is a process that involves the fertilization of the female gametophyte with one male gamete and fusion of another male gamete with the polar nuclei.
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Chapter 41 Solutions
Biological Science
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