2. mutations

Question 1

chromosome mutation

Answer 1

1. down syndrome = extra copy of chromosome 21
2. non-disjunction = chromosome 21 fails to separeate properly during meiosis = 1 cells gets extra copy
3. gamete with extra copy fuses to another gamete = 3 copies of chromosome 21

Question 2

mutagenic agents

Answer 2

increase rate of mutations e.g. UV radiation