Question

SECTION-A
1.
How is the entry of only one sperm into an ovum ensured during
fertilisation?
1
2.
Write the dual purpose served by dioxyribonucleoside triphosphates during
DNA replication.
1
1
3.
Write any two places where methanogens can be found.
4.
How does dsRNA gain entry into eukaryotic cells to cause RNA interference
1
(RNA i)?
1
5.
Why is the problem of predation more severe in plants than in animals?
6. Apple and cashew are not called true fruits. Give reason.
7.
Why do the red blood cells (RBCs) become sickle-shaped in a sickle-cell
anaemia patient?
Why is genetic variation important in the plant Rauwolfia?
Mention two causes of frameshift mutation.
Where are germ pores present in a pollen grain?
10.
Assertion: Not all copulations lead to pregnancy
11.
Reason: Fertilisation occurs in the ampullary-isthmic junctio
fallopian tube
(a) Both assertion and reason are true, and the reason ist
explanation of the assertion.​

Answer 1

plz ask it in one by one form

Answer 2

Answer:

1 - when a sperms reaches to an ovum they all try to crack the wall and form single nuclei

but the first sperm who is able to crack the wall of ovum , develops into new offspring because whenever the nucleus of ovum and sperm met there is another cells which get the msg nd they totally tighten the wall of ovum

rarely more than one sperm can fertilize the ovum

IT may help you