Sexual Reproduction Flashcards
What are gametes?
Sperm or egg cells
What does haploid mean?
Cell contains 1 of each chromosome
What is fertilisation?
When sperm enters an ovum to make a zygote
What is a zygote?
An egg after being fertilised by sperm
What is a blastocyst?
An early embryo
What do germ layers contain?
Stem cells that can divide into tissues
What is gastrulation?
Process of which the first cells of an embryo begin to specialise
What is meiosis?
Process of cell division that occurs in germ cells to create gametes
Explain crossing over in meiosis
At the chiasma, pairs may exchange chromosome segments
Explain independent assortment in meiosis
Each pair of homologous chromosomes align in the middle and seperate into gametes independently of each other
Why do gametes need to be haploid?
Because when fertilisation occurs, the gametes will combine to become a diploid zygote
What are germ cells?
The cells that will become sperm and eggs (undergo meiosis)
What are gonads?
The organ that is responsible for making gametes. These are testes or ovaries
Define reduction division
Halving the number of chromosomes in cells. This occurs in meiosis 1.
Define morula
A ball of 8-16 cells, totipotent
