Variation & Inheritance Flashcards
Name the two types of variation.
- Continuous
2. Discrete
How many genes control discrete variation?
One
How many genes control continuous variation?
More than one
How do you know if a variation is discrete?
The variation can be separated into distinct groups
What term is used to describe continuous variation because it is controlled by ‘many genes’?
Polygenic
How can you tell if a particular variation is discrete?
You can place them into distinct groups
How can you tell if a characteristic is continuous?
There are a range of values between a minimum and a maximum.
What is a gene?
A section of DNA that codes for a particular protein or trait
What is an allele?
Different forms of a gene
What do we call the alleles an organism has for a particular characteristic, usually written as letters e.g. Bb or BB
The genotype
What do we call the visible characteristics of an organism which occur as a result of its genes?
The phenotype
What term is used to describe an allele that always expresses itself whether it is partnered by a recessive allele or by another like itself?
Dominant
What term is used to describe the variant of a gene for a particular characteristic which is masked or suppressed in the presence of the dominant variant?
Recessive
What term is used to describe a genotype where the 2 alleles are identical?
Homozygous
What term is used to describe a genotype where the 2 alleles are different?
Heterozygous
