Cell division - Meiosis

Question 1

Prophase 1 (Homologous)

Answer 1

Homologous chromosomes pair together.

Two pairs of sister chromatids aligned together.

Called synapsis when the sister chromatids align

(A pair of homologous chromosomes is called a tetrad.)

Question 2

Metaphase 1(Homologous)

Answer 2

The tetrads move towards the equator. Line up as pairs instead of straight across.

Question 3

Anaphase 1(Homologous)

Answer 3

The sister chromatids move to the opposite sides of the poles

Question 4

Telophase 1 (Homologous)

Answer 4

Homologs uncoil

Spindle fibers disappear

cytoplasm divides the cell

• Two cells are formed and each cell contains one pair of sister chromatids (now a haploid)

Question 5

What can happen in Synapsis (Prophase 1)

Answer 5

In a process called synapsis, when the sister chromatids are aligned they cross over different pieces which results in different genetic combinations.

Question 6

Prophase 2 (Splitting)

Answer 6

(Exactly the same as prophase in mitosis)

Chromatin condenses and the nuclear membrane disappears

Question 7

Metaphase 2 (Splitting)

Answer 7

Chromosomes line up at the equator

Spindle fibers attach to the centrioles

Question 8

Anaphase 2 (Splitting)

Answer 8

Sister chromatids start to separate - through indentation

Question 9

Telophase 2 (Splitting)

Answer 9

Chromatids unwind

Spindle fibers break down

The nuclear membrane and nucleus reappear.

Question 10

(Chromosome disorders) Nondisjunctions

Answer 10

Occurs when chromosomes don’t separate properly during either anaphase 1 or anaphase 2.

Resulting in gametes having either too many (Down syndrome) or too little (Turner syndrome)

Question 11

(Gamete formation) Oogenesis

Answer 11

1) Oogonium= DIpliod cell (2n)
One oogonium can produce two eggs ones a polar body that isnt used and th eone that gets the most cytoplasm is the primary oocyte.

Mitosis

2) Primary oocyte= Diploid cell (2n)

Meiosis 1

3) Secondary oocyte= Haploid (n) (n)

Meiosis 2

Egg cell = * only if egg gets fertilized * (n) (n)(n)

Question 12

Difference between a somatic cell and a gamete cell.

Answer 12

Somatic = Cells that aren’t sex cells and they appear all throughout the body.

Gamete cells = Reproductive cells

Question 13

Process of spermatogonia

Answer 13

1) Starts as spermatogonium = Diploid cell(2n)

Mitosis

2) Primary oocytes= x2 Diploiod cell (2n)

Meiosis 1

3) Secondary spermatocyte = 2 hapliod (n) (n)

Meiosis 2

4) Spermatids= 4 hapliod sperm cells (n) (n) (n) (n)
(Then process begins again ending in sperm cells)