W HAT D O U THINK TODAY ’ S CLASS IS ABOUT ?

W HERE BABIES COME FROM !!! Aww………

I S THIS P OSSIBLE ?

Reproductive Cells / Gametes sperm ovum/ egg zygote Fuses to form embryo foetus

S PERM

O VUM / EGG

Z YGOTE

W HAT S PERM LOOKS LIKE UNDER THE M ICROSCOPE

W HAT THE OVUM LOOKS LIKE UNDER THE M ICROSCOPE

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

SEXUAL REPRODUCTION Sexual 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

S TRUCTURE OF S PERM & O VUM

S TRUCTURE OF S PERM HEAD: 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 SHAPE Enables efficient swimming LIGHT AND SMALL Enables fast movement

S TRUCTURE OF OVUM / EGG CYTOPLASM: 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 SIZE Enables sufficient food storage PLASMA CELL MEMBRANE Enables certain materials into the cell

ZYGOTE FORMATION Normal 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

A NSWERS A SSESSMENT S HEET 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

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