cytokineses

Question 1

Cytokinesis

what is the cleavage furrow

Answer 1

It begins during late anaphase and continues through telophase and beyond.
In case of animal cells, the cell organelles such as ribosomes and mitochondria become evenly distributed around the two daughter nuclei

Question 2

Centrosome

Answer 2

an organelle that serves as the main microtubule organizing centre of the animal cell as well as a regulator of cell-cycle progression

Question 3

Kinetochore

Answer 3

the protein structure on chromatids where the spindle fibres attach during cell division to pull sister chromatids apart

Question 4

Centromere

Answer 4

part of a chromosome that links sister chromatids. During mitosis, spindle fibers attach to the centromere via the kinetochore

Question 5

How are G1 and G2 different?

Answer 5

In G1 phase there is a high rate of metabolism and protein synthesis occurs to produce the enzymes needed for S phase. Most organelles are duplicated. In G2 phase the enzymes and proteins essential for physical cell division are produced and replication of centrioles is completed

Question 6

What is the main feature of anaphase?

Answer 6

The kinetochore of each chromatid splits, the separated chromatids are now termed as daughter chromosomes. They move towards opposite poles due to the interactions between the kinetochore and microtubules

Question 7

What are chromatids and where do they come from?

Answer 7

Before replication, one chromosome is composed of one DNA molecule. Following S phase each chromosome is now composed of two DNA molecules (in other words, DNA replication increases the amount of DNA but does not increase the number of chromosomes.) The two identical copies—each forming one half of the replicated chromosome—are called chromatids, and these chromatids eventually separate longitudinally to become individual chromosomes during the later stages of cell division.

Question 8

Why is the kinetochore important for cell division?

Answer 8

The kinetochore is the protein structure on chromatids where the spindle fibres attach during cell division to pull sister chromatids apart.

Question 9

How does the contractile ring form?

Answer 9

The actin cytoskeleton contracts, creating a cleavage furrow between the two cells. This continues until distinct membranes are formed.