WHAT DO U THINK TODAY’S CLASS IS ABOUT ?

WHERE BABIES COME FROM!!!

Aww………

IS THIS POSSIBLE?

Reproductive Cells / Gametes

sperm

ovum/egg

zygote

Fuses to form

embryo

foetus

SPERM

OVUM/EGG

ZYGOTE

WHAT SPERM LOOKS LIKE UNDER THE MICROSCOPE

WHAT THE OVUM LOOKS LIKE UNDER THE MICROSCOPE

ACTIVITY

Group Work: Observe the videosUse the blank sheet of paper, create a comparison table to identify the features you observe between the Sperm and the Egg/Ovum.

SPERM EGG/OVUM

1 1

2 2

3 3

4 4

5 5

6 6

SEXUAL REPRODUCTIONSexual reproduction is the reproduction that involves the fusion of two gametes or sex cells

The male gametes are called sperms and are produced in the testes

The female gamete is called ova and are produced in the ovaries

STRUCTURE OF SPERM & OVUM

STRUCTURE OF SPERMHEAD:Acrosome of digestive enzymes for breaking down of cell membrane of ovum

Haploid nucleus of 23 chromosomes

MIDDLE-PIECE:Mitochondria to produce energy for movement

TAIL:Beating movement or flagellum for propulsion

OTHER ADAPTATIONS:STREAM-LINED BODY SHAPEEnables efficient swimmingLIGHT AND SMALLEnables fast movement

STRUCTURE OF OVUM/EGGCYTOPLASM:Storage of food to enable ovum to survive while awaiting fertilisation

NUCLEUS:Haploid nucleus of 23 chromosomes

OUTER MEMBRANE:Hardens after one sperm has penetrated to prevent multiple fertilisation

OTHER ADAPTATIONS:LARGE SIZEEnables sufficient food storagePLASMA CELL MEMBRANEEnables certain materials into the cell

ZYGOTE FORMATIONNormal body cells have a diploid number of 46 chromosomes i.e. 23 from father and 23 from mother

Gametes have the haploid number of 23 chromosomes

This Fusion of gametes ensure that both parents genetic information is transferred to the child . This is called Variation.

When the gametes fuse together, they form a zygote.

The zygote will divide further by cell division or mitosis to form the embryo

ANSWERS ASSESSMENT SHEET

1. The diagram below shows a sperm and an ovum

A. (i) Name the part labeled P

 NUCLEUS

 

(ii) What does it contain?

CHROMOSOME/ DNA /GENETIC MATERIAL

B. (i) Name the part labeled Q?

FLAGELLUM / TAIL

(ii) What is its function?

IT ENABLES THE SPERM TO MOVE AND SWIM ABOUT

 C. Why is the ovum bigger than the sperm?

THE OVUM HAS MORE CYTOPLASM AND CONTAINS FOOD

2. C REPRODUCTIVE CELL 3. B. VARIATION

THE END