Unit 2 Topic 4 - Variation And Inheritance Flashcards
What is continuous variation?
Characteristics show a large range of values, can be measured, is controlled by more than one gene (polygenic)
What is discrete variation?
Can be divided into 2 or more distinct categories with no values in-between, is controlled by a single gene
How is information for discrete variation displayed?
In a bar graph
How is information for continuous variation displayed?
In a line graph or a histogram
A gene…
Is a section of DNA that codes for a characteristic
A genotype…
Is a combination of alleles coding for a characteristic
A phenotype…
Is a physical/outward appearance of a characteristic
Polygenic…
Is a characteristic controlled by the alleles of more than one gene
An allele…
Is different forms of a gene
Homozygous…
Is when an organism possesses 2 identical alleles of a gene
Heterozygous…
Is when an organism possesses 2 different alleles of a gene
Dominant…
An allele of a gene that is expresses in the phenotype. It is given a capital letter
Recessive…
An allele of a gene that only shows in the phenotype when it is paired with another recessive allele. It is given a small letter
Give an example of continuous variation
• weight
• height
• skin colour
• foot size
Give an example of discrete variation
• blood type
• natural hair colour
• eye colour
• ear lobes attached or unattached
