Subject

Biology

Class

NEET Class 12

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 Multiple Choice QuestionsMultiple Choice Questions

81.

Which one of the following proved effective for biological control of nematodal diseases in plants?

  • Pisolithus tinctorius

  • Pseudomonas cepacin

  • Gliocladium virens

  • Gliocladium virens

495 Views

82.

Which one of the following condition in humans is correctly matched with tis chromosomal abnormality /linkage?

  • Klinefelter's syndrom-44 autosomes + XXX

  • Colourblindness- Y-linked

  • Erythroblastosis foetails - X-linked

  • Erythroblastosis foetails - X-linked

259 Views

83.

What does the filiform apparatus do at the entrance into ovule?

  • It helps in the entry of pollen tube into a synergid

  • It prevents entry of more than one pollen tube into the embryo sac

  • It brings about opening of the pollen tube

  • It brings about opening of the pollen tube

577 Views

84.

Which one of the following is being tried in India as a biofuel substitute for fossil fuels

  • Jatropha

  • Azadirachta

  • Musa

  • Musa

324 Views

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85.

What is antissense technology? 

  • A cell displaying a foreign antigen used for synthesis of antigens

  • Production of somaclonal variants in tissue cultures. 

  • When a piece of RNA that is complementary to sequence is used to stop expression of a specific gene.

  • When a piece of RNA that is complementary to sequence is used to stop expression of a specific gene.

254 Views

86.

Haploids are more suitable for mutation studies than the diploids. This is because 

  • Haploids are reproductively more stable than diploids

  • mutagens penetrate in haploids more effectively than is diploids

  • haploids are more abundant in nature than diploids

  • haploids are more abundant in nature than diploids

286 Views

87.

Importance of day length in flowering of plants was first shown in 

  • Lemna

  • tobacco

  • Cotton 

  • Cotton 

349 Views

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88.

The linking of antibiotic resistance gene with the plasmid vector became possible with

  • DNA ligase

  • endonucleases

  • DNA polymerase

  • DNA polymerase


A.

DNA ligase

DNA ligase is used to seal the nicks that remain in recombinant DNA molecule. In fact, DNA ligase joins together the neighbouring nucleotides flanking a discontinuity in a DNA strand by forming a phosphodiester bond. A recombinant DNA molecules is a vector into which the desired DNA fragment has been inserted to enable its cloning in an appropriate host. 
Endonucleases are the enzymes that produce internal cuts called cleavage in DNA molecules. A class of endonucleases cleaves DNA only within or near those sites, which has specific base sequences, such endonucleases are known as restriction endonucleases. 
Exonucleases are enzymes that remove one or more nucleotide from the free ends.

DNA polymerase is the enzyme, which causes polymerization of nucleotides during DNA replication.

293 Views

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89.

Which one of the following statement is incorrect about menstruation? 

  • During normal menstruation, about 40 mL blood is lost

  • The menstrual fluid can easily clot

  • At menopause in a female, there is especially abrupt increase in gonadotropic hormones

  • At menopause in a female, there is especially abrupt increase in gonadotropic hormones

441 Views

90.

Consider the following statements concerning food chains

A) removal of 80% tigers from an area resulted in greatly increased growth of vegetation

B) removal of most of the carnivores resulted in an increased population of deers

C) length of food chains is generally limited to 3-4 trophic levels due to energy loss

D) the length of food chains may vary from 2 to 8 trophic level

Which two of the above statements are correct? 

  • B and C

  • C and D

  • A and D

  • A and D

265 Views

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