Cancer is most commonly classified a disease of uncontrolled cell division. Its development and progress can be linked to a series of changes in the activity of cell cycle regulators, e.g. cell cycle inhibitors stop the division process, if conditions are not right.

Synapsis – Occurs in zygotene of prophase-I

Chiasma formation – Occurs in pachytene stage of prophase-I

Terminalisation – Occurs during the diakinesis of prophase-I

Disjunction – Occurs in anaphase-I, where migration of tetrads to opposite poles occurs.

During zygotene of meiosis-I, the homologous chromosomes pair up and undergo synapses to form synaptonemal complex. Due to this pairing, chromosomes come together, get arranged side by side forming structures known as bivalents.

Recombinase enzyme is involved in the crossing over process occurring during pachytene stage of prophase-I. This enzyme helps in the recombination of genes between the homologous chromosomes.

The outer nuclear membrane is in continuity with endoplasmic reticulum. This outer membrane continuously produces numerous finger-shaped outgrowths, which explant into flat membranous sacs. This process is known as blebbing.

The endoskeleton of a cell is made up of endoplasmic reticulum. It is an extensive three-dimensional network of vascular system extending from nuclear membrane to plasma membrane. It provides stability and support to a cell.

Blue and red regions of the light spectrum are the most effective in photosynthesis.

A proton gradient develops in the lumen of the thylakoid of chloroplast because photolytic splitting of water occurs in it. As a result, the lumen of thylakoid becomes enriched with H+ ion. These H+ ions are transported from stroma of chloroplast to thylakoid membrane.

All the given statements are true for phasic development theory of vernalisation.