Molecular Basis of Inheritance — BIOLOGY STD 12 Science — Question

How does addition of a small amount of curd to fresh milk help in the formation of curd? Mention a nutritional quality that gets added to the curd.

OR

How does ‘starter’ added to milk help it to set into curd?

The antibody which is mainly present in the sandwich ELISA is:

1. Detection antibodies.
2. Capture antibodies.
3. Monoclonal antibodies.
4. All of the above

Retroviruses do not follow central Dogma. Comment.

Write the use of the following in biotechnology.
Chilled ethanol.

Are there any homologous organs in male and female reproductive system? If yes, give examples.

What is meant by semi-conservative nature of DNA replication?

Give difference: plasmid DNA and chromosomal DNA

Write benificial activity of following bacteria : (i) Rhizobium (ii) Azotobacter (iii) Streptomyces (iv) Lactobacillus

Identify a, b, c and d in the following table with reference to birth control?

Method	Example
a	Diaphragm
Female sterilisation	b
c	Saheli
d	Cut

What are pills? How do they act as contraceptive?