6.2 variation Flashcards
Define genotype.
The genetic makeup of an organism.
Define phenotype
The observable characteristics of an organism
What is a dominant allele?
An allele that will always be expressed.
What is a recessive allele?
An allele that will only be expressed if two copies are present.
What does homozygous mean?
The same alleles
What does heterozygous mean?
different alleles
What is continuous variation?
Variation that has no distinct categories and no limit to the value. It is mostly quantitative.
What are examples of continuous variation?
Height, weight, heart rate, finger length and leaf length.
How can continuous variation be represented?
By a line graph.
What is discontinuous variation controlled by?
Few genes
What is continuous variation controlled by?
Multiple genes as well as the environment.
What is discontinuous variation?
Where there is a distinct categories with no in between values, the data tends to be qualitative.
Were examples of discontinuous variation?
Tongue rolling eye colour fingerprints and blood group.
How can discontinuous variation be represented
On a bar graph.
What does polygenic mean?
It is controlled by many genes.