1 Curly hair is dominant over straight hair. Use H and h
Male is HH
Female is hh

There all have one dominant allele and one recessive allele (Hh) is heterozygous.

so curly hair one will be dominant

I hope this make sense to u :)

They use the si unit, or metric system its all the same thing

Im not sure if you still need this but the answer is 300 hz450 hz  i just did this lesson so , wish you the best of luck and take care