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 ... for middle finger lenght.

1. Homozygous
2. Heterozygous

Paul has two alleles for blonde hair.

Paul is ... for hair colour.

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 ... for hair length.

1. Homozygous
2. Heterozygous

Joe is heterozygous for hair colour. What is his genotype for hair colour?

1. AA
2. Aa
3. aa

Matt is homozygous recessive for finger length. What is his genotype for finger length?

1. BB
2. Bb
3. bb

Karl is homozygous dominant for earlobe form. What is his genotype 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

Two black dogs have puppies. All puppies are white. Which of the alleles is dominant? And what is the genotype of the parents?

1. White allele; BB
2. Black allele; BB
3. White allele; Bb
4. Black allele; Bb

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

1. Black hair
2. Brown hair
3. Blond 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