Multiple Choice Questions

Advertisement

A natural form of genetic engineering is exhibited by

  • Haemophilus influenzae

  • E.coli

  • Dolly

  • Agrobacterium tumefaciens


D.

Agrobacterium tumefaciens

Agrobacterium tumefaciens is known as natural genetic engineer. It is known to infect broad leaved crops such as, tomato, soyabean and tobacco. It causes tumours called crown galls. The tumour formation is induced by its plasmid-Ti. The plasmid integrates a segment of its DNA called T-DNA into chromosomal DNA of its host plant cells. It then causes tumours. i.e., gene transfer occurs without human effort.


Advertisement

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


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

  • Gene probing

  • Gene splicing

  • Gene mapping

  • Gene sequencing


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


Advertisement

Who formulated the chromosomal theory of linkage

  • T H Morgan and W Castle

  • Stern and Hotta

  • Pontecarvo

  • Bridges and Burns


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


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


Advertisement

Tumour promoter is

  • substance that activates transcription in cancer cells

  • oncogene promoting cancer

  • substance that produces tumour

  • All of the above