Human Reproduction IGCSE Biology What is reproduction Reproduction
Human Reproduction IGCSE Biology
What is reproduction? Reproduction is the production of new members of a species, replacing those who die due to old age, disease, competition etc. It is divided into two main types: Sexual reproduction involves two parents who have sex organs which produce sex cells. Asexual reproduction involves one parent and no sex cells
Most animals reproduce sexually so they need: Sex cells are called gametes The male gametes are sperm The female gametes are eggs (or ova) The sperm and egg have to meet and a sperm nucleus must fuse (join) with the egg nucleus. This process is called fertilisation. A fertilised egg is known as a zygote
Sperm Head- mainly a nucleus containing genetic material (DNA) Nucleus containing DNA Egg (ova) Cytoplasm with food store, cannot move Tail which allows it to move
Human Reproductive System Male
Human Reproductive System Female
Let´s get quizzical!
Copulation and Fertilisation: A Step-By-Step Guide
Step 1 – Find a partner • we instinctively select mates who will enhance the survival of the species. • Men are drawn to classically beautiful women -clear skin -bright eyes -shiny hair -good bone structure -red lips -rosy cheeks
But why…? ? • NOT because of fad or fashion • these qualities indicate youth and robust health • signs that a woman is in the peak of her childbearing years.
And what about the girls? • youth and physical health aren't essential to the male reproductive role • women instinctively favour mates with pronounced "alpha" qualities, -ability to dominate other males -bring home more than their share of the kill. • The assumption is that male dominance ensures the survival of the family group more than youth or beauty.
Step 2 – Courting Behaviour • Courtship may be rather simple, involving a small number of chemical, visual, or auditory stimuli; OR • it may be a highly complex series of acts by two or more individuals, using several modes of communication.
Step 3 – Having Sex • Male and female rats may have sex twenty times a day. . • For every 'normal' webpage, there are five porn pages. • Sex is biochemically no different from eating large quantities of chocolate. • A man's beard grows fastest when he anticipates sex. • Male bats have the highest rate of homosexuality of any mammal. • The average person spends 2 weeks of its life kissing. • 100 million sex acts performed daily worldwide
Step 4 - Fertilisation • We are going to watch ´The Great Sperm Race´- a great programme about fertilisation! • As we watch the show I want you to take notes on the following -10 new words -5 things you never knew -3 things that helped your understanding of the fertilisation process better -1 thing you will share with your family tonight!
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