Animal cytokinesis
• The spindle gets changed into dense fibrous and vesicular
structure on equator called mid body.
• In the middle region of cell below the cell membrane,
microfilaments get collected which induces the cell
membrane to invaginate.
• The furrow forms and deepens centripetally and finally
cleaves the parent cell into two daughter cells. This method
of cytokinesis is known as cleavage method.
• all cell organelles (mitochondria, Golgi complex, lysosomes,
er, ribosomes, etc.) are also distributed between the two
daughter cells.Plant cytokinesis
• It differs from animal cytokinesis due to the presence of rigid
cell wall. In lower plants cytokinesis occurs by cleavage
method (like animal cell) and in higher plants it takes place
by cell plate method.
• In cell plate method small vesicles of Golgi complex are
collected at the equator. Here, spindle persists for some time
called phragmoplast.
• all vesicles fuse to form two sheets which enclose a matrix
or film. This film becomes solidified to form cell plate or
middle lamella.
• It grows centrifugally and finally comes in contact with
lateral walls of parent cell.
• Now phragmoplast disappears. Cellulose, hemicellulose and
pectin are deposited on either side of cell plate. It forms
primary wall.
Some anglerfish employ an unusual mating method. The
male anglerfish are significantly smaller than females and are
equipped with extremely well developed olfactory organs or
large specialised eyes that aid in identifying mates (females)
in dark environments. Males mature only when they parasitise
a female. When a male bites a females, he bites into her skin
and releases an enzyme that digests the skin of his mouth and
her body fusing the pair down to the blood vessel level. The
male increases in volume and becomes dependent on female
for survival by receiving nutrients via their shared circulatory
system and providing sperms in return. Multiple males can
be incorporated into a single female. They live and remain
reproductively functional as long as female lives.