Biology MCQs

Biology

Chromosome and DNA


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#25

Pyrimidine base contain 4 carbon atoms and purine bases contains 5 carbon atoms. How many carbons atoms are there in nucleotide containing cytosine?

A)  8

B)  9

C)  10

D)  11

Answer:   B
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#26

How does DNA sythesis along the lagging strand differ from that of leading strand?

A)  An RNA primer is needed

B)  Nucleotides are added to the 5' end

C)  Helicase synthesize okazaki fragments

D)  Okazaki fragment linked by DNA ligase

Answer:   D
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#27

The consecutive bases of DNA (a triplet) provide the code, what is the maximum number of different triplets that could occur?

A)  16

B)  20

C)  24

D)  64

Answer:   D
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#28

In a genetic engineering exp. A piece of DNA containing 6000 nucleotides is transcribed and translated into protein. How many amino acids are required?

A)  500

B)  1000

C)  3000

D)  2000

Answer:   B
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#29

A synthetic mRNA is made by using only two types of nucleotides, containing adenine and cytosine. How many different condons could it contain?

A)  2

B)  4

C)  8

D)  16

Answer:   C
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#30

How many different polypeptides, each consisting of r amino-acids, can be made. If the number of different amino acids available is n?

A)  nr

B)  rn

C)  nr

D)  n

Answer:   A
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#31

Which process does not occur during the formation of mRNA?

A)  Condensation

B)  Polymerization

C)  Replication

D)  Transcription

Answer:   C
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#32

An  mRNA is 336 nucleotides long, including the intiation and termination condons. The number of amino-acids in the protein translated from this mRNA is?

A)  110

B)   111

C)  112

D)  330

Answer:   B
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