CELL DIVISION : MEIOSIS

Welcome students to our

SCIENCE CLASS!

Sir Lindzie Swain G. Domen

Identical to parent cell

1 round of PMAT

DIVIDE AND CONQUER

4 haploid cells

2 rounds of PMAT

Mitosis

Meiosis

Sex cells

Body cells

2 diploid cells

UNIDENTICAL TO PARENT CELL

Topic Of The Day

CELL DIVISION:MEIOSIS

Sir Lindzie Swain G. Domen

REVISIT

IT'sSCI-MULATIONtime!

MEIOSIS

1. Involves sex cells (sperm cell and egg cell) or gametes.

2, • Reduces the chromosomes number in half from two sets (diploid) into a single set (haploid).

3. Two rounds of cell division (Meiosis I and Meiosis II)

4.Four daughter cells, each with half the chromosome number as the original parent cell (father and mother).

MEIOSIS 1

INTERPHASE

TII

G1, s pHASE, G2

P1

m1

PHASES OF MEIOSIS P.M.A.T

AII

A1

MII

t1

PII

MEIOSIS II

Cytokinesis

IT'sSCI-MULATIONtime!

GAMETOGENESIS

From the word “gamete” which means sex cells and “genesis” which means origin.

Egg Cell

Ovary

Sperm Cell

Testes

SPERMATOGENESIS

• Derived from the word “sperma” which means “sperm” and “genesis” which means “origin”. • The production of sperm cells in the testes. • Meiosis produces four small cells of similar size called spermatozoa or sperm.

OOGENESIS

• Derived from the word oo- which means “egg” and “genesis” which means “origin”. • The production of egg cells in the ovary. • Meiosis I in the ovary, the cell will produce two cells -one big and one small (polar body) this polar body may or may not divide, if it does then 2 small cells are produced but will disintegrate. • Meiosis II in the ovary, produces one big and one small cell from the first big cell in the meiosis I.

Why MEIOSIS important?

Ensures the correct number of chromosomes to an offspring.

Responsible for genetic variation.

SUMMARY

• Meiosis involves sex cells.
• Meiosis undergoes two rounds of PMAT (Meiosis I and Meiosis II)
• Meiosis results into differentiation and sexual reproduction of species.

• Meiosis results into genetic diversity.

TRUEorFALSE

TRUE

Meiosis is responsible for genetic variation and reproduction of species.

FALSE

TRUE

After meiosis 1, the cell will then enter again into the interphase (G1, S Phase and G2).

FALSE

TRUE

Humans have a total of 46 chromosomes in 23 pairs.

FALSE

TRUE

Gametogenesis is the production of body cells, such as skin cells, muscle cells and so on.

FALSE

TRUE

The purpose of crossing over during Prophase 1 is important in achieving genetic variation/diversity.

FALSE

GREAT JOB!

DO YOU HAVE ANY QUESTIONS?

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LINDZIE SWAIN DOMEN

THANK YOU!Keep safe !

LESSON OBJECTIVES

Define MEIoSIS, OOGENESIS AND SPERMATOGENESIS

Explain the significance of meiosis in maintaining the chromosome number.

differenriate Spermatogenesis and Oogenesis.

IDENTIFY THE PHASEs OF MEOSIS

SCI-MULATION ofMEIOSIS