Reproduction Flashcards
What is fertilisation?
It involves the haploid nuclei of the sperm and egg fusing and restoring the diploid condition.
What are the three methods of contraception?
Mechanical, surgical and surgical
What is an example of mechanical contraception?
Condom - acts as a barrier to prevent sperm entering the woman.
What is an example of chemical contraception?
Contraceptive pill - taken regularly by the woman and prevents the ovaries from releasing eggs by changing hormone levels
What is an example of surgical contraception?
Vasectomy - cutting of sperm tubes, preventing sperm from entering the penis
Female sterilisation - cutting of the oviducts preventing ova moving through the oviducts and being fertilised.
What are the advantages of using a condom?
Easily obtained and also prevents STIs.
It can also be unreliable if not used properly
What are the advantages of using a contraceptive pill?
Very reliable
Can cause some side affects such as weight gain and can also increase the risk of blood clots.
What are the advantages of both surgical contraceptions?
Virtually 100% reliable
Very difficult or impossible to reverse
Describe the menstruation cycle.
Menstruation ( days 1-5 ) Thickening of the uterus lining ( days 6-13 ) Ovulation ( day 14 ) Fertilisation ( days 11-16 ) Implantation ( day 22 )
Describe the process of vitro fertilisation.
The woman is given fertility drugs so that several eggs are produced
These are collected from the ovaries surgically
These are then mixed with sperm cells in a laboratory
Successful embryos are placed in the mothers uterus. If it is successful an embryo will implant in the uterus lining
Usually a small number of embryos are placed in the mothers uterus to give a balance between ensuring a successful pregnancy and avoiding multiple births.
How long do sperm and egg cells survive?
Egg - 24-48 hours
Sperm - 3 days
