2.4 Variation And Inheritance Flashcards
What does dominant mean?
Stronger allele, represented by a capital letter
What does recessive mean?
Weaker allele, represented by a smaller letter
What does heterozygous mean?
Individual with two different alleles
What does homozygous mean?
Individual with two identical alleles
What is a phenotype?
The physical characteristics of an organism
What is a genotype?
The set of genes possessed by an individual
List three variations that are controlled by polygenic inheritance?
- human height
- root length
- hand span
What does polygenic mean in terms of variation?
A feature which is controlled by more than one gene (continuous variation shows that)
What are three examples of continuous variation?
- Height
- Weight
- Arm Span
Give a description of continuous variation?
Continuous variation describes the differences which show a large range of values, between a maximum and a minimum
Why do ‘expected’ and ‘actual/observed’ phenotypic ratios differ?
Because fertilisation is a random process and too few offspring is produced
What is discrete variation?
Discrete variation describes differences which can be grouped into distinct sets
Name three examples of discrete variation?
- Flower colour in plants
- Eye colour in humans
- Ability to roll tongue
