31.

Host cells in response to viral infections produces a low molecular weight protein, that protect other cells against further viral infection. This substance is

• phytotoxin

• antibody

• hormone

• interferon

Which one of the given statement is not true for Archaeopteryx?

• Each wing had three clawed digit

• Hind feet with five digits

• Long jointed lizard like tail

• Thecodont teeth on both jaws

A natural form of genetic engineering is exhibited by

• Haemophilus influenzae

• E.coli

• Dolly

• Agrobacterium tumefaciens

Tumour promoter is

• substance that activates transcription in cancer cells

• oncogene promoting cancer

• substance that produces tumour

• All of the above

Who formulated the chromosomal theory of linkage

• T H Morgan and W Castle

• Stern and Hotta

• Pontecarvo

• Bridges and Burns

Water pollution is best assessed by determining

• DO and BOD

• BOD and turbidity

• DO and acidity

• Hardness and alkalinity

The organisms that thrives on the remains of dead plants and animals are categorised as

• carnivore

• omnivore

• scavangers

• predators

In which of the following, determination of order of bases in a DNA molecule takes place

• Gene probing

• Gene splicing

• Gene mapping

• Gene sequencing

A pea with white flower was crossed with another pea with white flower. When they selfed, the F₂ generation produced purple and white in the ratio of 9:7. The reason for the result is that

• it is typical monohybrid Mendelian ratio

• purple flower colour is dominant over white

• it is a complementary factor

• None of the above

Which of the following statement is not true about Griffith's experiment?

• The experiment was conducted in 1928

• The experiment occurs with Streptococcus pneumoniae

• R and S-strain of bacteria

• The experiment proves the process of transduction