DNA and Genetics - Chapter 3

• Biologie
• Middelbare school
• vwo
• Leerjaar 3

● Jan has one allele for a long middle finger and one allele for a short middle finger. Jan is

1. Homozygous
2. Heterozygous

Paul has two alleles for blonde hair. Paul is..

1. Homozygous
2. Heterozygous

Guinea pigs can have short or long hair. A long-haired guinea pig and a short-haired guinea pig have a nest of babies. They only have long-haired babies. The babies are

1. Homozygous
2. Heterozygous

A certain flower has white, red and pink flowers. Which phenotypes are homozygous and heterozygous?

Write down the genotype of the following people. Joe is heterozygous for hair colour

1. AA
2. Aa
3. aa

Write down the genotype of the following people. Matt is homozygous recessive for finger length

1. BB
2. Bb
3. bb

Write down the genotype of the following people. Karl is homozygous dominant for earlobe form

1. EE
2. Ee
3. ee

00:10

What is the difference between a gene and an allele?

00:27

Dominant allele<br>

recessive allele<br>

an allele that is always expressed in the phenotype

an allele that is only expressed in the phenotype if there is no dominant allele present

Which of the alleles is dominant?
A white and a black dog have puppies. All puppies are white;

1. White allele
2. black allele

Which of the alleles is dominant? Ralph is heterozygous for hair colour. His hair is black

1. black hair
2. brown hair
3. blon hair

Which of the alleles is dominant? Hanna has blue eyes. Her father and mother had brown eyes

1. brown eyes
2. blue eyes

Which of the alleles is dominant? A white horse is heterozygous for hair colour;

1. Black hair
2. White hair