If you do not keep fit what are you likely to suffer with?
Each human has 23 chromosomes?
What happens when two egg cells are fertilized by two different sperm cells?
Non identical twins are born
Identical twins are born
No one is born
What are genes?
sections of chromosomes
To stay fit you need to avoid?
Aerobic respiration is with oxygen?
Oestrogen is produced by the pituitary