Arrange the following steps of DNA fingerprinting in the correct sequence:
(A) Isolation of DNA and its digestion by restriction endonucleases. (B) Hybridisation using a labelled VNTR probe. (C) Transferring of separated DNA fragments to synthetic membranes. (D) Detection of hybridised DNA fragments by autoradiography. (E) Separation of DNA fragments by electrophoresis.
The correct sequence is DNA isolation and digestion → electrophoresis → Southern blotting (transfer) → hybridisation with labelled VNTR probe → autoradiography.
Which of the following statements are correct with reference to a transcription unit?
(A) A transcription unit in DNA is defined primarily by three regions: promoter, structural gene and terminator. (B) The promoter is said to be located towards the 5'-end of the structural gene. (C) The promoter is a DNA sequence that provides the binding site for RNA polymerase. (D) The promoter defines the template and coding strands. (E) The terminator is located towards the 3'-end of the coding strand and defines the end of transcription.
Choose the correct answer from the options given below:
All the given statements correctly describe the organisation and function of a transcription unit.
I. Gross primary productivity minus respiration losses
B. Net primary productivity
II. Rate of formation of new organic matter by consumers
C. Gross primary productivity
III. Rate of biomass production
D. Secondary productivity
IV. Rate of production of organic matter during photosynthesis
Productivity is the rate of biomass production. Net primary productivity equals GPP minus respiration losses. Gross primary productivity is the rate of photosynthesis, while secondary productivity is the rate of biomass formation by consumers.
In which one of the following, the ovules are not enclosed by an ovary wall and remain exposed?
Gymnosperms such as Pinus bear naked ovules that are not enclosed within an ovary. Angiosperms have enclosed ovules, while bryophytes do not produce ovules.
Which of the following statements are correct with reference to packaging of DNA helix?
(A) Histones are organized to form a unit of eight molecules called histone octamer. (B) Histones are negatively charged basic proteins. (C) Histones are rich in the basic amino acid residues lysine and arginine. (D) The positively charged DNA is wrapped around the histone octamer to form nucleosome. (E) The packaging of chromatin at higher levels requires an additional set of proteins called non-histone chromosomal proteins.
Choose the correct answer from the options given below:
Histones form an octamer and are rich in lysine and arginine. DNA is negatively charged, while histones are positively charged. Higher-order chromatin packaging requires non-histone chromosomal proteins.
