Human Reproduction Flashcards
How are gametes produced ?
When cells divide by meiosis
Where is sperm produced ?
Testes
Where are eggs produced ?
Ovaries
What produces cells that are NOT genetically identical?
Meiosis
What is the tail on a sperm cell called ?
Flagellum
What is external fertilisation?
Fertilisation that occurs outside the body
What is internal fertilisation?
Fertilisation that occurs inside the body
• this fertilisation is more likely
What happens when the sperm reaches the ovum ?
Its nucleus must enter the ovum and fuse with the ovums nucleus
How many chromosomes does each human gamete have ?
Half the normal number
• 23
What is fertilisation ?
Fertilisation is the fusion of haploid male and female gametes, restoring diploid number of chromosomes in the zygote
How many chromosome does the zygote (adult cell) have ?
46
Describe human fertilisation
- during sexual intercourse, sperm passes along the sperm duct and is mixed with a fluid. This mixture is called semen
- it is ejaculated into the vagina of the female out of the urethra m. The sperm then begins to swim towards the oviducts
- fertilisation occurs between the ovum and the sperm as there nucleus fuse
- the zygote travels down the oviduct. During this time the zygotes forms into an embryo
- it implants into the lining of the uterus wall
What hormone does the placenta secrete and what does it do ?
Progesterone which prevents the embryo from aborting
When do we call the embryo a foetus ?
When it looks human
What is the membrane called that encloses the developing embryo ?
Amnion