On the beginning of diplotene stage, synaptonemal complex dissolutes and recombined homologous chromosomes separate from each other.

Interphase is the period between the two successive mitotic cell divisions.

As there is no boundary membrane for the nucleolus that is why its content material seems to be continuous with nucleoplasm.

This is because mesosomes also participates in aerobic cellular respiration in prokaruotes as mitochondrion does in eukaryotes.

(a) Plant cells cannot undergo cytokinesis like animal cells because they have a rigid/inextensible cell wall.
(b) (i) In plant cells, cytokinesis starts with the formation of a precursor, called cell plate.
(ii) This extends from the centre ofthe cell towards the lateral walls and cuts the cell into two halves, each with a daughter nucleus.
(iii) During cytokinesis, the cell organelles like mitochondria, plastids, etc. also get distributed between the daughter cells.

Stages during the recombination of genes occurs in meiosis are
(i) Crossing over is exchange of genes between the non-sister chromatids of homologous chromosomes. It occurs at recombination nodules during pacytene stage of prophase-I of meiosis-I and is regulated by recombinase enzyme.
(ii) Arrangement of bivalents at the equator of the spindle during metaphase-I of meiosis.

Mitochondria are the organelles in which the most important part of the cellular respiration occurs, i.e. the ATP production.
Mitochondria are organelles bounded by two lipid membranes. The inner membrane unfolded to the interior of the organelle forming cristae that define the internal space known as mitochondrial matrix and where mitochondrial DNA (mtDNA), mitochondrial RNA (mtRNA), mitochondrial ribosomes and respiratory enzymes can be found.
Mitochondria are found in eukaryotic cells in high number and are also more abundant in those cells that their own DNA, RNA and ribosomes. They can even have the ability to self-replicate.

(a). Prophase I has been divided into the following five phases, based on the chromosomal behaviour;
(i) Leptotene,
(ii) Zygotene,
(iii) Pachytene,
(iv) Diplotene and
(v) Diakinesis
(b) During leptotene, the compaction of chromosomes continues and the chromosomes become visible under light microscope.
(c) During zygotene, the hormologous chromosomes start pairing, in the process, called synapsis; it is accompanied by the formation of synaptonemal complex and the pair of synapsed hormologous chromosomes, is called a bivalent.
(d) During pachytene, the bivalents appear as tetrads and recombination nodules appear indicating the sites of crossing over.
(e) Crossing over occurs between non-sister chromatids of homologous chromosomes; the process is catalysed by enzyme, recombinase.
(f) Diplotene is marked by the dissolution of the synaptonemal complex and the tendency of the members of bivalents to separate except at sites of cross overs, called chiasmata.
(g) Diakinesis is marked by terminalisation of chiasmata; the chromosomes are fully condensed and the nuclear envelope and nucleolus have disappeared.

(a) Cell is considered the fundamental structural and functional unit of life because anything less than a complete structure of a cell does not ensure independent living.
(b) Unicellular organisms are capable of
(i) independent existence.
(ii) performing all the essential life processes.
(c) (i) Anton Von Leeuwenhoek
(ii) Theodore Schwann