SEX CELLS FERTILISATION The sex cells or gametes

SEX CELLS & FERTILISATION The sex cells or gametes in mammals are: eggs and sperm. • Eggs are produced in the ovaries • Sperm are produced in the testes.

FEMALE BITS OVIDUCT UTERUS VAGINA OVARY

MALE BITS URETHRA PENIS SPERM DUCT TESTIS

The Story The female gametes are the _____ which are produced by the _______. Eggs are released from the ovaries and travel along the ______, tubes leading to the uterus. The ______ is the tube in which sperm are deposited during sexual intercourse. WORDBANK ovaries eggs oviducts vagina

WORDBANK urethra penis sperm duct testes The male gametes are sperm, which are produced in the ____. The sperm travel from the testes along the _______. These are long tubes which join with the tube coming from the bladder. The final journey of the sperm is along the _____, the tube leading from the bladder out of the ____.

Fertilisation • Sperm and eggs both contain a nucleus. • Fertilisation is when these 2 nuclei fuse together to form a zygote (a fertilised egg cell) • A zygote contains the genetic information from both parents • Fertilisation is a random process

EGG Fertilisation occurs in the oviduct. SPERM

SEX CELLS & FERTILISATION The sex cells or gametes in flowering plants are found in: - pollen and ovules. • Pollen is produced by the anther. Pollen contains the male gamete • Ovules are produced by the ovary which contains the female gamete.

PETALS (ANTHER) STAMEN STIGMA (FILAMENT) OVARY OVULE SEPAL NECTARY

FERTILISATION IN FLOWERING PLANTS Pollination • A pollen grain lands and becomes attached to the stigma. The pollen grain bursts open and then starts to grow a pollen tube which grows towards the ovule

• Diagram showing the growth of the pollen tube down to the ovary and into an ovule. GROWTH OF POLLEN TUBE

FERTILISATION • The nucleus of the male sex cell in the pollen fuses with the nucleus of the female sex cell in the ovule. • This is called FERTILISATION MALE & FEMALE NUCLEI FUSE A ZYGOTE IS FORMED

• When the male and female nuclei fuse together a zygote is formed which contains the genetic information of both parent plants.

Variety in Plant Offspring Pollen grains from different parent plants may land on a stigma of a flower. The different male gamete nuclei fuse with different female gamete nuclei in the ovary. Zygotes are all genetically different. Offspring produced by sexual reproduction show a great variety.

• Stick in the fertilisation grid – 1, 2, 3, 4 represent different male gamete nuclei. A, B, C , D represent different female gamete nuclei. Fill in the table to show all the combinations possible. (You should end up with 16 different zygotes)