Unit 2 - KA4 variation and inheritance Flashcards
What is discrete variation?
When a characteristic can be placed into distinct groups. Can also be referred to as single gene inheritance, this means it is controlled by one gene.
What is continuous variation?
When a characteristic can be measured and falls into a wide range between a minimum and maximum number. Can also be referred to as polygenic inheritance, this means it is controlled by many genes.
What is a phenotype?
The physical appearance of a characteristic in an organism, determined by the genotype.
What is a genotype?
The combination of alleles that an organism possesses usually represented by letters
What is an allele?
The name given the the form of a gene
Definition of recessive
A weaker allele, represented by a small letter.
Definition of dominant
Stronger allele, represented by a capital letter.
Definition of homozygous
A genotype in which two alleles for a characteristic are the same (EE or ee)
Definition of heterozygous
A genotype on which two alleles for a characteristic are different (Ee)
Why are predicted phenotype ratios among offspring not always achieved?
Fertilisation is a random process
