ch.12 bio

late G2, turns on MPF

An enzyme that dephosphorylates MPF occurs in which phase? what does it do?

inhibits kinase activity

An enzyme that phosphorylates MPF?

Gap phase

During the blank phase no DNA synthesis occurs. but in this phase organelles replicate, and additional cytoplasm is made in preparation to cell division

MPF activation

Forms the mitotic spindle apparatus and culminates in the condensation of chromosomes

Centrosome

The MTOC is located where during mitosis?

S phase

The stage in which DNA replication occurs

G1 phase

Variation in cell-cycle between cells is due to which phase?

Polar microtubules. Prophase

What is it called when the spindles extend out of the MTOC and overlap each other? The formation of this is during which phase?

G0 phase

When non deviding cells get stuck in in G1 phase, this is called? nerve cells, and muscle cells are examples of this

astral microtubules

When the chromosomes are aligned on the metaphase plate, what structure holds the spindle poles in place at opposite sides of the cell, by attaching to membrane proteins?

kinetochore microtubules

When the nuclear envelope disintegrates during pro metaphase, what is the name of the structure that attaches to the centromere of the chromosomes?

sister chromatid

chromatid copies that remain attached to at their centromere are called?

prophase

chromosomes condense and spindle aapparatus is formed

chromatin

chromosomes consist of DNA wrapped around the globular histone proteins. This DNA protein material is called what? (chromosomes are made of this)

G2 checkpoint

if DNA is damaged or if chromosomes are not replicated correctly, the removal of the inactivating phosphate is blocked. which chpoint is this?

prometaphase

nuclear envelope erodes, giving way to attachment of microtubules to chromosomes

telophase

nuclear envelope reforms around each set of daughter chromosomes, and they also de-condense. two independent nuclei have formed

Chromatid

once strand of a replicated chromosome

M-phase checkpoint

problems involved with this checkpoint may result in daughter cells with too many or too few of chromosomes?

genes

segments of chromosomes that code for RNA and proteins

chromosome

single long DNA double helix that is wrapped around proteins called histones, in a highly organized manner

anaphase, shrinking kinetochore microtubules

sister chromatids divide into daughter chromosomes that are pulled to opposite pulls. Which phase is this and how?

motor proteins in overlapping polar microtubules push the poles away from each other

what moves the spindle poles further away in anaphase?