B5.1.4 - Dominant and recessive genes Flashcards
1
Q
What are alleles?
A
Different versions of the same gene
2
Q
How many copies does a dominant allele need for it to be expressed?
A
1
3
Q
How many copies does a recessive allele need for it to be expressed?
A
2
4
Q
What is used to represent a dominant allele?
A
An uppercase letter such as ‘B’
5
Q
What is used to represent a recessive allele?
A
A lower case letter such as ‘b’
6
Q
What does homozygous mean?
A
Organism which has 2 copies of the same allele
7
Q
What does heterozygous mean?
A
Organism which has different alleles of a gene
8
Q
What are some examples of dominant characteristics?
A
- Brown eyes
- Free ear lobes
- straight nose
- ability to roll tongue
- freckles
9
Q
What are some examples of recessive characteristics?
A
- Blue eyes
- Joined ear lobes
- Upturned nose
- Inability to roll tongue
- no freckles
