4.6.1.8 Sex Determination Flashcards
1
Q
How many pairs of chromosomes do human body cells have?
A
- 23 pairs
2
Q
What do 22 pairs of chromosomes do?
A
- control characteristics
- chromosome in each pair look very similar
3
Q
What do the 23rd pair of chromosome do?
A
- carries sex determining genes
- two chromosomes can look different to each other
- Y chromosomes are much smaller than X chromosomes
4
Q
What are the two possible chromosomes in the 23rd pair?
A
- X chromosomes
- Y chromosomes
5
Q
What happens when cells undergo meiosis to form a gamete?
A
- one sex chromosome goes into each gamete
6
Q
What is the 23rd chromosome pair a female has?
A
- two X chromosomes
- only pass on X chromosomes in eggs
7
Q
What is the 23rd chromosome pair a male has?
A
- one X chromosome
- one Y chromosome
- can pass on X or Y chromosomes in their sperm
8
Q
What can show sex inheritance?
A
- punnett squares
- 50% chance of child being male
- 50% chance of child being female
