Sexual Reproduction In Flowering Plants — BIOLOGY STD 12 Science — Question

1. What precaution(s) would you recommend to a patient requiring repeated blood transfusion?
2. If the advise is not followed by the patient there is an apprehension that the patient might contract a disease that would destroy the immune system of his/her body.

Explain with the help of schematic diagram only how the immune system would get affected and destroyed.

Why do you think the zygote is dormant for sometime in a fertilised ovule?

How LABs are useful to us explain.###Give a brief account on importance of lactobacillus bacteria in house hold products.

Lymph nodes are secondary lymphoid organs. Explain the role of lymph nodes in our immune response.

How does animal classification prove biological evolution?

Certain molecular processes are given in column (A). Provide the terms given to these processes in column (B), after selecting them from the terms:
Recombination, gene regulation, prokaryotic transcription, eukaryotic transcription, translation, replication, gene transfer, DNA fingerprinting

S.No.	Column A	Column B
(i)	DNA → DNA
(ii)	DNA → hRNA
(iii)	mRNA → Protein
(iv)	Repressor Protein + Operator → No transcription

Is it true that carpets and curtains/ drapes placed on the floor or wall surfaces can reduce noise level. Explain briefly?

Where is acrosome present in humans? Write its function.

Name the source of statin and state its action on the human body.
OR
Name a microbe used for statin production. How do statin lower blood cholesterol level?

In a certain population, the frequency of three genotypes is an followers.
Genotypes: BB Bb bb
Frequency: 22% 62% 16%
What is the likely frequency of B and b alleles?