B5.1.5/B5.1.6 - Genetic crosses

Question 1

Who discovered the basic laws by which characteristic are inherited?

Answer 1

Gregor Mendel discovered this by experimenting with pea plants

Question 2

What happens if you cross a homozygous green pea pod with a homozygous yellow pea pod?

Answer 2

All of the offspring are heterozygous but they are all green

Question 3

How can you predict a genetic cross?

Answer 3

By using a Punnett square

Question 4

What happens if you cross a heterozygous green pea pod with a heterozygous green pea pod?

Answer 4

The phenotypes produced are GG, Gg and gg in the ratio of 1:2:1

Question 5

What happens if you cross a green heterozygous pea pod plant and a yellow homozygous yellow pea pod?

Answer 5

50% of the plants produced will have yellow pea pods and 50% will have green pea pods

Question 6

How many pairs of chromosomes do humans have?

Answer 6

23 pairs

Question 7

What chromosomes can male gametes have?

Answer 7

They can have an X or Y chromosome

Question 8

What chromosomes can female gametes have?

Answer 8

They can only have an X chromosome

Question 9

At pregnancy what is the chance of conceiving a boy or a girl?

Answer 9

50:50