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.
I. Accumulation of dark coloured amorphous colloidal substance
B. Detritus
II. Release of inorganic nutrients by the activity of microbes in soil
C. Mineralisation
III. Breaking down of complex organic matter into simpler substances
D. Humification
IV. Dead remains of plants and animals including faecal matter
Decomposition breaks down detritus. Detritus consists of dead organic matter. Mineralisation releases inorganic nutrients. Humification forms dark-coloured humus.
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.
