Multiple Choice Questions

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Cry-I endotoxins obtained from Bacillus thringiensis are effective against 

  • mosquitoes

  • flies

  • nematodes

  • nematodes


B.

flies

Insect-resistant transgenic plants contain either a gene from the bacterium Bacillus thuringiensis or some other gene. The cry gene of bacillus thuringiensis produces a protein which forms crystalline inclusion in the bacterial strains. Cry-I endotoxins are effective gains Lepidoptera (eg flies). Cry- V and Cry-VI proteins are effective against are ingested by insects, they are dissolved in the alkaline juices present in the midgut lumen. The gut proteases process them hydrolytically to release the core toxic fragments. The toxic fragments are believed to bind to specific high-affinity receptors present in the brush border of midgut epithelial cells and causing their swelling and eventual lysis.

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Main objective of production/use of herbicide resistant GM crops is to

  • eliminate weeds from the field without the use of manual labour

  • eliminate weeds from the field without the use of herbicides

  • encourage eco- friendly herbicides

  • encourage eco- friendly herbicides

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What is true about the isolated small tribal populations? 

  • There is a decline in population as boys marry girls only from their own tribe

  • Hereditary diseases like colour blindness do not spread in the isolated population

  • Wrestlers who develop strong body muscles in their lifetime pass this character on their progeny

  • Wrestlers who develop strong body muscles in their lifetime pass this character on their progeny

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To which type of barriers under innate immunity, do the saliva in the mouth and the tears the eyes, belong?

  • Cytokine barriers

  • cellular barriers

  • Physiological barriers

  • Physiological barriers

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The table below gives the populations (in thousand) of ten species (A-J) in four areas (a-d) consisting of the number of habitats given within  brackets aginst each. study the table and answer the question which follows: 

Area and number of habitats

Species and their populations (in thousands) in the area

A

B

C

D

E

F

G

H

I

J

a(11)

b(11)

c(13)

d(12)

23

1.2

0.52

6.0

-

3.1

1.1

9.0

-

10.3

10.2

-

0.62

-

1.5

3.0

-

8.2

1.1

11.2

11.3

0.9

0.48

2.4

1.4

4.2

0.8

8.4

2.2

4.1

3.2

10.2

11.1

4.8

0.4

3.3

0.8

7.3

11.3

2.1

 Which area out of a to d shows maximum species diversity?

  • b

  • c

  • d

  • d

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Human insulin is being commericially produced from a transgenic species of 

  • Escherichia

  • Mycobacterium 

  • Rhizobium

  • Rhizobium

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Consider the statements given below regarding contraception and answer as directed thereafter

A) Medical Termination of Pregnancy (MTP) during first trimester is generally safe

B) Generally chances of conception are nil until mother breast -feeds the infant upto two year

C) Intrauterine devices like copper T- are effecitve contraceptives

D) Contraception pills may be taken upto one week after coitus to prevent conception

Which two of the above statements are correct?

  • B, C

  • C, D

  • A, C

  • A, C

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Which one of the following is not observed in biodiversity hot spots? 

  • Endemism

  • Accelerated species loss

  • Lesser interspecific competition

  • Lesser interspecific competition

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Darwin's finches are an excellent example of 

  • adaptive radiation

  • seasonal migration

  • brood parasitism

  • brood parasitism

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Which one of the following pairs of nitrogenous bases of nucleic acids, is wrongly matched with the category mentioned against it?

  • Thymine, Uracil - Pyrimidines

  • Uracil, Cytosine - Pyrimidines

  • Guanine, Adenine - Purines

  • Guanine, Adenine - Purines

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