IB Biology HL D2.1.2 Cytokinesis Questions

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;

Marking points for 8c continued on next page....

Marking guidance:

Max 6 for similarities.

Allow clearly annotated diagrams.

8 max

8c continued ....

8.

c

k. in plant cells spindle fibres attach to walls;

I. 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;