Molecular Basis of Inheritance Class 12

In a DNA strand the nucleotides are linked together by

• (a) glycosidic bonds

• (b) phosphodiester bonds

• (c) peptide bonds

• (d) hydorgen bonds.

The net electric charge on DNA and histones is

• (a) both positive

• (b) both negative

• (c) negative and positive, respectively

• (d) zero.

Which of the following statements is the most appropriate for sickle cell anaemia ?

• (a) It cannot be treated with iron supplements.

• (b) It is a molecular disease.

• (c) It conferes resistance to acquiring malaria.

• (d) All of the above.

The first genetic material could be

• (a) protein

• (b) cabohydrates

• (c) DNA

• (d) RNA

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

• (a) chromosome 21 and Y

• (b) chromosome 1 and X

• (c) chromosome 1 and Y

• (d) chromosome X and Y.

Who amongst the following scientist had no contribution in the development of the double helix model for the structure of DNA ?

• (a) Rosalind Franklin

• (b) Maurice Wilkins

• (c) Erwin Chargaff

• (d) Meselson and Stahl

Which of the following steps in transcription is catalysed by RNA polymerase ?

• (a) Initiation

• (b) Elongation

• (c) Termination

• (d) All of the above

Control of gene expression takes place at the level of

• (a) DNA-replication

• (b) transcription

• (c) translation

• (d) none of the above

Which was the last human chromosome to be completely sequenced ?

• (a) Chromosome 1

• (b) Chromosome 11

• (c) Chromosome 21

• (d) Chromosome X

In some viruses, DNA is synthesised by using RNA as template. Such a DNA is called

• (a) A – DNA

• (b) B – DNA

• (c) cDNA

• (d) rDNA.