Molecular basis of inheritance

In a DNA strand the nucleotides are linked together by

• glycosidic bonds
  
  
  

• phosphodiester bonds

• peptide bonds

• hydorgen bonds.

The electric charge on DNA and histones is

• both positive

• both negative

• zero

• negative and positive respectively

The human chromosome with the highest and least number of genes in them are respectively

• chromosome 21 and Y

• chromosome 1 and X

• chromosome 1 and Y

• chromosome X and Y.

In prokaryotes, control of gene expression takes place at the level of

• transcription

• translation

• DNA replication

• All of the above

Which was the last human chromosome to be completely sequenced ?

• Chromosome X

• Chromosome 21

• Chromosome 1

• Chromosome Y

If the sequence of nitrogen bases of the coding strand of DNA in a transcription unit is: 5’ – ATGAATG – 3’, the sequence of bases in its RNA transcript would be

• 5’ – AUG A AUG – 3’

• 5’ – UACUU AC – 3’

• 5’ – CAUUCAU – 3’

• 5’ – GUAAGUA – 3’.

If the base sequence of a codon in mRNA is 5’ – AUG – 3′ the sequence of tRNA pairing with it must be

• 5’ – UAC – 3’

• 5’ – CAU – 3’

• 5’-AUG – 3’

• 5’ – GUA – 3’

In E. coli, the lac operon gets switched on when

• lactose is present and it binds to the repressor

• repressor binds to operator

• RNA polymerase binds to the operator

• lactose is present and it binds to RNA polymerase

If a double stranded DNA has 20% of cytosine, what will be the percentage of adenine in it ?

• 20%

• 30%

• 40%

• 60%

How far is each base pair from the next one in DNA double helix model ?

• 2 nm
  
  
  

• 3.4 nm

• 34 nm

• 0.34 nm