Chapter 2.5 ~ Cell Division

Question 1

Cell Division ~ Meiosis

Answer 1

Meiosis is the combination and division of two different gametes ~ the ovum and sperm and that’s why they only have one set of chromosomes. This type of nuclear division prevents the doubling of chromosomes.
23 chromosomes and 23 chromosomes pair up to create a diploid gamete

Stages:
A diploid (paired chromosomes) gamete divides and forms two haploid daughter gametes.

Question 2

Gamete

Answer 2

A sex chromosome

Question 3

Diploid

Answer 3

A full gamete ~ 46 chromosomes

Question 4

Haploid

Answer 4

A halved gamete ~ 23 chromosome

Question 5

Chromosomes In Cells

Answer 5

22 pairs of chromosomes are autosomes ~ non-sex chromosomes

1 pair of chromosomes are gametes ~ sex chromosomes

Question 6

Mitosis Stages

Answer 6

1. Prophase: The cell get ready to divide ~ the protein needed for tue new cell is produced
2. Prometaphase: The cell membrane gets broken down to make the new cell
3. Metaphase: The chromosomes align themselves ~ still attached to each other
4. Anaphase: The chromosomes divide and move to separate side of the cell
5. Telophase: The cell starts to form all the other necessary parts needed to complete a cell around the remaining chromosomes ~ ready to divide
6. Cytokinesis: Another cell membrane is made and the cell divides making the final two cells

Question 7

Fertilisation

Answer 7

When a haploid gamete from each gender fuse together -combine- to form a diploid zygote. This zygote has 23 paternal chromosomes and 23 maternal chromosomes. Once meiosis is completed then mitosis takes place and the zygote divides.

Question 8

Sex Determination

Answer 8

XX ~ Female

XY ~ Male

Question 9

Cell Division ~ Mitosis

Answer 9

Mitosis is the division of all somatic cells ~ essentially asexual reproduction. This occurs when a somatic cell has been damages or is about to die. This results in the exact replication of the previous cell unless mutation occurs