Unit 2 - Key Area 4 - Variation and Inheritance Flashcards
What is variation?
Variation is the difference which exists amongst members of a species.
Combining genes from two parents contributes to variation within a species.
What is discrete variation?
Discrete variation is controlled by one gene (single gene inheritance).
Measurements of characteristics showing discrete variation place organisms into distinct groups and can be shown using a bar chart.
Give examples of discrete variation
Eye Colour
Tongue Rolling
Blood Type
What is continuous variation?
Continuous variation is controlled by more than one gene (polygenic inheritance).
Measurements of characteristics showing continuous variation place organisms within a range of values between a minimum and a maximum and can be shown using a histogram.
Give example of continuous variation
Height
Weight
Length
What is a gene?
Section of DNA coding for a protein
What is an allele?
Different versions of a particular gene
What is a phenotype?
Particular version of a physical characteristic
What is a genotype?
A statement of the alleles for a characteristic
What does dominant mean
The gene which is always shown in a phenotype
What does recessive mean?
Gene which is masked by a dominant gene
What does homozygous mean?
Two alleles of a particular gene are identical
What does heterozygous mean?
Two alleles of a particular gene are different
What P mean?
Refers to the parent generation
What does F1 mean?
Refers to the first generation of offspring
