Cell cycle and cell division; Mitosis, atypical forms of mitosis

Question 1

What is the cell cycle

Answer 1

-The life of cells that divide and reproduce is called the cell cycle
-It is controlled by a set of genes called cell cycle genes

Question 2

Control and duration of cell cycle

Answer 2

Control; carried out specific proteins (cyclins, cyclin-dependent kinases, growth factors, etc)

Duration; varies widely in different cell types (for normally proliferating human cells- about 24 hours)

Question 3

The life cycle in animal cells

Answer 3

The set of phenomena associated with growth, development and reproduction, according to the program of instructions encoded in DNA and inherited from the parent cells.

Question 4

The life cycle in bacteria cells

Answer 4

Coincides with the cell cycle and consists of continuous alteration of growth and division.

Question 5

The stages of the cell cycle

Answer 5

-Mitosis (M phase)
-Interphase (consists of 3 phases)
-G1 (gap phase 1)
-S (Synthetic)
-G2 (gap phase 2)

Question 6

G1 (gap phase 1)

Answer 6

-Pre-synthetic; between the end of mitosis and initiation of DNA synthesis
-Lasts 8-10 hours
-Enzymes for the synthesis of nucleotides are formed
-Formation of deoxyribonucleotides begins
-DNA polymerase, Mg2+
-Diploid nuclei
-Centrioles are doubled
-The cytoplasm begins to grow

Question 7

S (synthetic)

Answer 7

-6-8 hours
-DNA and histones are synthesised
-DNA is duplicated
-Tetraploid nuclei