II. Cell is metabolically active and continuously grows but does not replicate its DNA
C. G2 phase
III. Synthesis of DNA occurs and the amount of DNA per cell doubles
D. M phase
IV. Proteins are synthesized while cell growth continues
G₁ is the growth phase, S is the DNA synthesis phase, G₂ involves protein synthesis and preparation for mitosis, and M phase is the phase of actual cell division.
Arrange the following steps of somatic hybridisation in the correct sequence:
(A) Digestion of cell walls
(B) Isolation of naked protoplasts
(C) Fusion of protoplasts to get hybrid protoplast
(D) Isolation of single cells from two different varieties of plants
(E) Growing of hybrid protoplast to form a new plant
Single cells are isolated first, cell walls are digested to obtain protoplasts, protoplasts are fused, and the hybrid protoplast is cultured to regenerate a new plant.
I. Specialised cells in the vicinity of guard cells
B. Casparian strips
II. Endodermal cells rich in starch
C. Subsidiary cells
III. Tissue between xylem and phloem
D. Starch sheath
IV. Endodermal cells with suberin deposition
Conjunctive tissue lies between xylem and phloem. Casparian strips are suberin deposits in endodermis. Subsidiary cells surround guard cells. Starch sheath refers to starch-rich endodermis.
The main criteria used for Five Kingdom Classification proposed by R.H. Whittaker (1969) included:
(A) Cell structure (B) Body organization (C) Presence of flagellum (D) Reproduction (E) Phylogenetic relationships
Choose the correct answer from the options given below:
Whittaker's five-kingdom classification was based on cell structure, body organisation, mode of nutrition, reproduction and phylogenetic relationships. Presence of flagellum was not a criterion.
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.