In maize, hybrid vigour is exploited by:

1. bombarding the seeds with DNA

2. crossing of two inbred parental lines

3. harvesting seeds from the most productive plants

4. inducing mutations

Which one of the following is a viral disease of poultry ?

1. Salmonellosis

2. Coryza

3. New castle disease

4. Pasteurellosis

Crop plants grown in monoculture are:

1. low in yield

2. free from intraspecific competition

3. characterised by poor root system

4. highly prone to pests

Triticale, the first man-made cereal crop, has been obtained by crossing wheat with: 

1. rye

2. pearl millete

3. sugarcane

4. barley

In order to obtain virus-free plants through tissue culture the best method is:

1. protoplast culture

2. embryo culture

3. anther culture

4. meristem culture

The name of the Indian scientist associated with Green Revolution in India is

1. H.G. Khorana

2. M.S.Swaminathan

3. Homi Bhaba

4. C.N.R. Rao.

Which is Indian dwarf wheat ?

1. T.dicoccum

2. T. sphaerococcum

3. T. turgidum

4. T. aestivum

People recovering from long illness are often advised to include the alga Spirulina in their

diet because it

1. makes the food easy to digest

2. is rich in proteins

3. has antibiotic properties

4. restores the intestinal microflora.

Cattle fed with spoilt hay of sweet clover which contains dicumarol

1. are healthier due to a good diet

2. catch infections easily

3. may suffer vitamin K deficiency and prolonged bleeding

4. may suffer from beri beri due to deficiency of B vitamins

Somaclonal variation can be obtained by

(a) application of colchicine

(b) irradiation with gamma rays

(c) tissue culture

(d) hybridisation.