Genetics-VI-Biology Test Series for NEET - 2020

Test Preparation on Genetics – VI Biology Test Series for NEET - 2020

There are 64 types of codons in genetic code dictionary
because

1There are 64 types of tRNA's found in cell
2There are 44 meaningless and 20 codons for amino acids
3There are 64 amino acids for coding
4Genetic code is triplet

(d) Genetic code is triplet and in each triplet code three
bases are present (4³).

The codons causing chain termination (stop codons) are
(a) TAG, TAA, TGA (b) GAT, AAT, AGT
(c) AGT, TAG, UGA (d) UAG, UGA, UAA

(d) Termination codons are also known as the non-sense
codons or stop codons becuase they stop the process of
protein synthesis being not coded for amino acid during
translation.

Which one of the following is the starter codon

1 AUG
2UGA
3UAA
4UAG

In 125 amino acid sequence if the codon for 25^th amino acid
is mutated to UAA, then

1A polypeptide of 24 amino acids is formed
2A polypeptide of 124 amino acids is formed
3No polypeptide are formed
4A polypeptide of 25 amino acids is formed

Whose experiments cracked the DNA and discovered
unequivocally that a genetic code is a “triplet”

1Nirenberg and mathaei
2Hershey and Chase
3Morgan and Sturtevant
4Beadle and Tatum

What is not true for genetic code

1A codon in mRNA is read in a non-contiguous fashion
2It is nearly universal
3It is degenerate
4It is unambiguous

Which one of the following pairs of codons is correctly
matched with their function or the signal for the particular
amino acid

1AUG, ACG – Start/Methionine
2UUA, UCA – Leucine
3GUU, GCU – Alanine
4UAG, UGA – stop

Read the following four statements (A-D)
(A) In transcription, adenosine pairs with uracil
(B) Regulation of lac operon by repressor is referred to as
positive regulation
(C) The human genome has approximately 50,000 genes
(D) Haemophilia is a sex-linked recessive disease
How many of the above statements are right

1Two
2Three
3Four
4One

(a) Regulation of lac operon by repressor is referred as
negative regulation. Human genome has approximately
30000 genes.

mRNA directs the building of proteins through a sequence of

1Exons
2Introns
3Codons
4Anticodons

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Test Preparation on Genetics – VI Biology Test Series for NEET - 2020

There are 64 types of codons in genetic code dictionarybecause

The codons causing chain termination (stop codons) are(a) TAG, TAA, TGA (b) GAT, AAT, AGT(c) AGT, TAG, UGA (d) UAG, UGA, UAA

Which one of the following is the starter codon

In 125 amino acid sequence if the codon for 25th amino acidis mutated to UAA, then

Whose experiments cracked the DNA and discoveredunequivocally that a genetic code is a “triplet”