Cell growth and division

Question 1

Define cell division.

Answer 1

Cell division is the process required for the growth of the human and replacement of dead cells. Two processes are involved: mitosis and meiosis. Cells are reproduced as part of a cell cycle.

Question 2

What are the two processes involved in cell division?

Answer 2

Mitosis and Meiosis

Question 3

What is mitosis?

Answer 3

The production of genetically identical cells for growth and replacement of cells

Question 4

What is meiosis?

Answer 4

For the creation of genetic variable gametes

Question 5

What is interphase?

Answer 5

This is the phase which occurs between cell divisions, this step is subdivided into G1, S and G2 phase (G stands for gap and S for synthesis).

Question 6

What happens during G1?

Answer 6

The cell grows and the cellular contents are duplicated

Question 7

What happens during the S phase?

Answer 7

The 46 chromosomes are replicated called DNA replication

Question 8

What happens during G2?

Answer 8

Further growth and checking of contents

Question 9

What are the four stages of mitosis?

Answer 9

Prophase, metaphase, Anaphase, Telophase

Question 10

What happens during prophase stage of mitosis?

Answer 10

Chromatin condenses into chromosomes. Spindles are microtubules act like a rope pulling the chromosomes around the cell.

Question 11

What happens during metaphase stage of mitosis?

Answer 11

Chromosomes align at equatorial plate pulled by the spindles

Question 12

What happens during anaphase stage of mitosis?

Answer 12

The chromatids break apart and pulled to opposite ends of the cell.

Question 13

What happens during telophase stage of mitosis?

Answer 13

New nuclear membranes form around each of the two chromosomes set.

Question 14

Summarise the 4 stages of mitosis?

Answer 14

PMAT
Prophase - PAIRS of chromosomes become visible
Metaphase - chromosomes line up in the MIDDLE of the cell
Anaphase - chromosomes pulled APART
Telophase - TWO nuclear membranes formed

Question 15

What is cytokinesis?

Answer 15

Cytoplasm divides two separate cells form. Each cell has 46 different chromosomes.

Question 16

Define the terms haploid, diploid and zygote?

Answer 16

Haploid is 23 chromosomes
Diploid is 46 chromosomes
Zygote when two haploid cells come together (sperm and egg) they make a diploid

Question 17

What is independent assortment?

Answer 17

The Principle of Independent Assortment describes how different genes independently separate from one another when reproductive cells develop.

Question 18

What is the crossing over stage?

Answer 18

It is when the chromosomes come together and fragments of chromosomes containing genes are exchanged between chromatids. This takes place in Prophase I.

Question 19

What are the steps of meiosis.

Answer 19

1. Interphase
2. Prophase I
3. Metaphase I
4. Anaphase I
5. Telophase I

Question 20

What happens during interphase in meiosis.

Answer 20

growth of cell and DNA replication.

Question 21

What happens during Prophase I in meiosis.

Answer 21

Chromatin condenses into chromosomes. Spindles are microtubules act like a rope pulling the chromosomes around the cell.
And homologus chromosome pairs from bivalents (they crossover and genes to be exchanged).

Question 22

What happens during Metaphase I in meiosis.

Answer 22

Homologous pairs align at the equatorial plate, pulled by spindles.

Question 23

What happens during Anaphase I in meiosis.

Answer 23

The sister chromatids do not break apart, instead the homologous chromosomes separate, with one going to each end of the cell.

Question 24

What happens during Telophase I in meiosis.

Answer 24

New nuclear membranes form around each of the two chromosomes set.

Question 25

In cytokinesis which one phase of stage two is different to mitosis, and why.

Answer 25

Prophase II, but the spindles generally form perpendicular to the orientation displayed in meiosis I.