Biotechnology and its Applications — BIOLOGY STD 12 Science — Question

Name important defence mechanisms in plants against herbivory.

Name two diseases each, which are transmitted in the following ways:

1. Through contaminated food and water.
2. Through insect vectors.
3. Through the air/ droplet inhaled.

Given below are the events that are observed in artificial hybridisation programme. Arrange them in the correct sequential order in which they are followed in the hybridisation programme.
(a) Re-bagging; (b) Selection of parents; (c) Bagging; (d) Dusting the pollen on stigma; (e) Emasculation; (f) Collection of pollen from male parent.

Differentiate between egg cells and secondary nucleus found in embryo sac of angiosperms.

Explain the role(s) of the following in Biotechnology:

1. Restriction endonuclease.
2. Gel – electrophoresis.
3. Selectable markers in pBR322.

How is DNA recombinant technology helpful in detecting the presence of mutated genes in the cancer patients?

(a) Describe the role of selectable marker in r-DNA technology.
(b) Write the name of one such selectable marker considered useful for E. coli.
(c) Write one reason why it is considered an advantageous selectable marker

Identify 'a', 'b', 'c', 'd', 'e' and 'f' in the table given below:

No.	Syndrome	Cause	Characteristics of affected individual	Sex Male/Female/Both
1	Down’s	Trisomy of 21	‘a’ (i) (ii)	'b'
2	‘c’	XXY	Overall masculine development	‘d’
3	Turner’s	45 with OX	‘e’ (i) (ii)	‘f’

A vector is engineered with three features, which facilitates its cloning within host cell. List three features and explain each one of them.

In the table given below, select and enter one correct device out of the following: Oral pill, Condom, Copper T, Saheli, Vasectomy, Diaphragm, Tubectomy, Cervical cap

S.No.	Method of Birth Control	Device
1	Barrier
2	IUD
3	Surgical Technique
4	Administering Hormones