What is an allele
A gene that gives different traits
What is a trait?
A genetically determined characteristic
What is a dominant allele?
An allele that produces a certain phenotype in an organism always represented by a CAPITAL letter
What is a recessive allele?
An allele that will not affect an individual. This is represent by a LOWER case letter and needs 2 copies of the same lower case letter to represent a trait
What does homozygous mean?
The same alleles
What does heterozygous mean?
Two different alleles
What does genotype mean?
The genetic information of a person
What does phenotype mean?
This is the resulting appearance of an individual from the genetic makeup
How many copies of a dominant allele is needed for a characteristic to be expressed?
1
How many copies of a recessive allele is needed for a characteristic to be expressed?
2
What are the 3 recessive conditions you need to know?
What is the only dominant condition you need to know?
Huntington Disease
To get all marks in your exam for punnet square questions what MUST you include?
What do each square of the punnet square represent?
25%
What does 2 squares of the punnet square represent?
50%
What does 3 squares of the punnet square represent?
75%
Can you be a carrier of Huntington’s disease?
No
What is/causes Down’s syndrome?
A condition where a baby is born with an extra chromosome. A baby is at higher risk of getting this if their mother is over the age of 35
What are the symptoms/affected PIES of Down’s syndrome?
How is Down’s syndrome treated?
What is Huntington’s disease?
A brain disease that is inherited
What causes Huntington’s disease?
What are the symptoms/affected PIES of Down’s syndrome?
Can Huntington’s disease be cured?
No