cell cycle and mitosis Flashcards
what are the main stages of the cell cycle?
G1, S, G2 and M
what are histone proteins?
proteins round which condensed chromosomes are wrapped.
why is DNA condensed?
it prevents damage to the DNA.
what is cohesin?
it is a protein that holds sister chromatids together.
what is the difference between closed and open mitosis?
open creates two separate nuclei. closed creates one with two sets of DNA.
what happens during prophase?
DNA condenses.
what happens during prometaphase?
The nuclear envelope dissolves and spindle fibres begin to move towards the middle of the sister chromatid complex from the poles.
what happens during metaphase?
Cohesin dissolved and the chromosomes dissolve along the midline.
what happens during anaphase?
Cohesin dissolved and the chromosomes dissolve along the midline
what happens during telophase?
New nuclear envelope forms and the chromosomes decondense.
what happens during cytokinesis?
the cytoplasm divides.
how do the mitochondria and chloroplast divide?
by a process of fission and fusion.
how to the Golgi and ER divide?
they break up and move passively or with the assistance of spindle fibres to all the daughter cells.
how do the centriole and centromeres divide?
by transcription and translation.
cytokinesis in animals involves what protein?
myosin- to pinch the cleavage furrow.
cytokinesis in plants involves what?
during anaphase vesicles start to form in the middle of the cell and deposit cellulose. small imperfections become the plasmodestomata.
which part of a plant is best used for observations of cell division?
root tip.
what is a carcinoma?
a cancer originating on the external and internal body coverings like skin or the lining of organs.
what is a sarcoma?
Sarcomas are cancers originating on the supportive/connective tissue like ligaments and cartilage.
what is leukaemia and lymphomas?
Leukaemia and lymphomas are cancers originating in the blood forming tissue like bone marrow.
