Science 1.9 Key Words
Words you must learn
Different forms of the same gene. They can be dominant or recessive.
A genetically determined characteristic.
The particular alleles of an organism.
The observable characteristics of an individual resulting from its genotype.
An organism that is homozygous for a particular trait.
An individual with two alleles that are the same for a particular trait.
An individual with two alleles that are different for a particular trait.
A diagram that shows the phenotypes of related individuals.
A cross between an organism whose genotype for a certain trait is unknown and an organism that is homozygous recessive for that trait so the unknown genotype can be determined from the offspring.
An allele which is always expressed, even if only one is present. Expressed with an upper-case letter (i.e. ‘A’).
An allele which is only expressed when two of them are present. Expressed with a lower-case letter. (i.e. ‘b’).