Presentation is loading. Please wait.

Presentation is loading. Please wait.

Nuclear division of sex cells

Similar presentations


Presentation on theme: "Nuclear division of sex cells"— Presentation transcript:

1 Nuclear division of sex cells
Meiosis Nuclear division of sex cells

2 Meiosis Two divisions of a single nucleus occur
Produces gametes (sex cells) Eggs Sperm Fertilization- joining of sex cells Producing a zygote

3 Meiosis Because meiosis joins 2 cells, unlike mitosis that occurs in 1 cell Each sex cell should only contain 1 copy of each chromosome (23 total chromosomes….no pairs) So this is why nuclear division occurs twice This results in Meiosis 1 and Meiosis 2

4 Meiosis Produces gametes (sex cells) Interphase
Time between cell divisions 3 phases G1 phase- growth S phase- DNA replicate creating a duplicate chromosome G2 phase- prepare to divide

5 Meiosis Meiosis- Prophase I Pairs of homologous chromosomes
Remember each chromosome

6 Meiosis Meiosis- Metaphase I
Homologous chromosome pair line up in the center of the nucleus

7 Meiosis Meiosis- Anaphase I
Chromosomes separate and move to the opposite ends of the nucleus

8 Meiosis Meiosis- Telophase I and Cytokinesis I
Chromosomes reach opposite sides of the cell New nuclear membrane forms The new nucleus each contains a chromosome with 2 chromatids The cell divides

9 Meiosis Meiosis- Prophase II No replication takes place
Each cell contains one chromosome from the homologous pair

10 Meiosis Meiosis- Metaphase II
Chromosomes line up in the middle of the cell

11 Meiosis Meiosis- Anaphase II Chromatids separate
Move towards the poles (opposite sides of the nucleus)

12 Meiosis Meiosis-Telophase II and Cytokinesis II
Nuclear membrane forms around the chromosome 4 new cells are formed each with half the number of chromosomes Example humans 23 chromosomes

13

14 Meiosis End Products 4 Daughter cells 23 chromosomes each
Create either an egg or sperm cell


Download ppt "Nuclear division of sex cells"

Similar presentations


Ads by Google