Cytokinesis splits the cytoplasm after nuclear division. In animal cells, a contractile ring pulls the membrane inward; in plant cells, vesicles form a cell plate. The selected HL question compares these mechanisms.
Eukaryotes are a diverse group of organisms, including animals and plants.
Compare and contrast the processes of mitosis and cytokinesis in animal and plant cells.
Similarities: [6 max]
a. (in both plants and animals) produces two genetically identical daughter cells;
b. maintains the chromosome number/genome of cell / produces diploid/2n cells;
c. used for generation of new cells/cell replacement/tissue repair/growth;
d. in prophase the chromatin/chromosome condenses/formation of chromatids/supercoiling of chromosomes;
e. supercoiling of DNA around histones (to form nucleosomes);
f. microtubules/microtubule motors to move chromosomes/chromatids;
g. in metaphase chromosomes align in equator of cell;
h. in anaphase separation of chromatids;
i. in telophase two nuclei/cells form / nuclear membrane/envelope reforms
OR
cytokinesis is the division into two cells;
Differences:
j. in animal cell centrosomes/centrioles facilitates the organization of the mitotic spindle/ spindle poles/microtubules;
k. in plant cells spindle fibres attach to walls;
l. in animal cells, the plasma membrane is pulled inwards around the equator to form a cleavage furrow in cytokinesis
OR
in animal cells actin and myosin pinch cell membrane to split cytoplasm/cytokinesis;
m. in plant cells a cell plate forms (at the equator) to develop into the new cell wall to achieve cytokinesis
OR
in plant cell vesicles (containing pectin) assemble sections of membrane/cell wall (at/across the equator) to achieve splitting/cytokinesis;
Marking guidance:
Max 6 for similarities.
Allow clearly annotated diagrams.
8 max