Chapter 18 - Cytokinesis

Anaphase begins when the ______ enzyme, activated by the ______ complex, degrades ______ to allow sister chromatid separation

separase; anaphase-promoting complex (APC); cohesins

The spindle assembly checkpoint delays anaphase if (1) kinetochores are not ______ to MTs or (2) they lack proper ______ from opposite poles

attached, tension

During anaphase A, chromosomes move toward spindle poles due to MT ______ at the ______ end, mediated by ______ kinesins (Kin-13)

depolymerization; plus; Kin-I

hromosomes stay attached to depolymerizing MTs during anaphase A via the ______ kinesin ______ and the ______ complex

Kin-N; CENP-E; Ndc80

Anaphase B is driven by polar MT ______ and sliding mediated by ______ kinesins (Kin-5), with additional pulling forces from ______ at the cell cortex

elongation; Kin-N; dynein

During telophase, daughter chromosomes arrive at the poles, the nuclear envelope reforms due to ______ of nuclear lamins, and chromatin begins to ______

dephosphorylation, de-condense

Cytokinesis begins during ______ or ______, involving the contraction of a ______ ring to form a cleavage furrow

anaphase, telophase, contractile

The contractile ring is made of ______ filaments and ______ II, and it positions itself at the cell equator using signals from the ______ spindle

actin, myosin, mitotic

The cleavage furrow region is marked by active ______ GTPase, which promotes assembly of the contractile ring through ______ and ______ II

RhoA, formins, myosin

Formins help ______ and elongate actin filaments, while Myosin II forms ______ filaments that pull on the actin filaments to contract the ring

nucleate, bipolar

Final cell separation occurs at the ______, a structure containing a membrane ring and MT bundles, and involves ______ trafficking events

midbody, membrane

Membrane abscission at the midbody involves F-actin, ______, and the ______ complex, which mediate final membrane fission

septins, ESCRT

Unlike animals, some organisms like plants rely on ______ fusion instead of a ______ ring to divide their cytoplasm

membrane, contractile

For successful cytokinesis, the contractile ring must be properly assembled, ______ to drive furrow ingression, and then ______ after division

constricted; disassembled

The cleavage site is positioned by negative signals from the ______ spindle and positive signals from the ______ spindle

astral, central