The Cell Cycle

Question 1

What is the cell cycle

Answer 1

Is the process that all body cells use to grow and divide. There are two phases interphase and mitotic phase.

Question 2

What are the functions of the cell cycle

Answer 2

• Growth of organisms
• Repair of body tissue
• Asexual reproduction
• Replacement of worn out/damaged cells

Question 3

What are the products of the cell cycle

Answer 3

Two genetically identical daughter cells

Question 4

Interphase stages

Answer 4

G1- synthesis of proteins, organelles replicate, cells increase in size
S- replication of each chromosome
G2- cells continue to grow in size, duplicated DNA is checked for errors and energy stores increase.

Question 5

What is the mitotic phase

Answer 5

Mitosis and cytokinesis

Question 6

Stages of mitosis

Answer 6

Prophase
Metaphase
Anaphase
Telophase

Question 7

What is prophase

Answer 7

• chromosomes condense and thicken forming sister chromatids.
• centrioles go to opposite poles of the cell and spindle fibres attach to the centromeres
• nuclear envelopes disappear

Question 8

what is Metaphase

Answer 8

-Chromosomes are aligned in the centre by spindle fibres at the equator

Question 9

what is Anaphase

Answer 9

-centromere divide and chromatids separate form each other by spindle fibres. They are pulled to opposite poles.

Question 10

what is Telophase

Answer 10

Chromatids uncoil becoming long and thin, they are now chromosomes. A nuclear envelope reforms around chromosomes.

Question 11

what is Cytokinesis

Answer 11

Where the cytoplasm divides and two genetically identical daughter cells are formed.

Question 12

What g0

Answer 12

When the cell leaves the cell cycle due to the cell being damaged.

Question 13

What is Meiosis

Answer 13

When 4 daughter haploid cells are formed which are genetically different due to the process of crossing over and independent assortment.

Question 14

Prophase 1 for meiosis

Answer 14

Homologous chromosomes pair up forming bivalentes. They are brought together as a result of chromatids entangling. This is called crossing over.

Question 15

what happens at Metaphase 1

Answer 15

Homologous pairs of chromosomes assemble along the equator. The orientation is random and paternal or maternal could face either direction. This is called independent assortment. Allowing different combinations of variations of alleles.

Question 16

what happens at Anaphase 1

Answer 16

Homologous proteins are pulled to opposite poles and chromatids stay joined. Sections of DNA on sister chromatids break off and exchange DNA. This is chiasmata.

Question 17

what happens at Telophase

Answer 17

Chromosome assemble at each pole and a nuclear membrane reforms.

Question 18

what happens at Prophase 2

Answer 18

Chromosomes consist of 2 chromatids and condense. The nuclear envelope breaks down and spindle formation begins.

Question 19

what happens at Metaphase 2

Answer 19

Individual chromosomes line up on the equator.

Question 20

what happens at Anaphase 2

Answer 20

Chromatids of different chromosome are pulled to opposite pole after division of centromeres

Question 21

what happens at Telophase 2

Answer 21

Chromatids assemble at the poles. The chromosomes uncoil and form chromatin. Nuclear envelope reforms. Cytokinesis happens.

Question 22

What is homologous chromosome

Answer 22

Are chromosomes one from each parent. They have the same genes but different alleles

Question 23

What happens if a damaged DNA is discovered at G2

Answer 23

They cell cycle is halted and the cell tries to repair the DNA.