17.1-17.5: Studying inheritance etc... Flashcards
Genotype
The genetic constitution of an organism.
describes all the alleles an organism has
Phenotype
The observable or biochemical characteristics of an organism.
What is the phenotype a result of?
The interaction between the expression of the genotype and the environment.
Gene
A length of DNA, made up of a sequence of nucleotide bases, that normally code for a polypeptide
Alleles
The existence of genes in 2 or more different forms.
Allele
One of the different forms of a gene.
Locus
Position of a gene on a particular DNA molecule
How many alleles can occur at the locus
Only one allele of a gene can occur at the locus of any one chromosome
Homologous chromosomes
A pair of chromosomes (1 maternal, 1 paternal) that have the same gene loci and therefore determine the same features.
Homologous chromosomes are found in
diploid organisms
Homozygous
The allele on each of the chromosomes is that same
Heterozygous
Two alleles for a characteristic are different
Codominant
Two alleles expressed in the phenotype
Effects of codominance on the phenotype
2
phenotype is a blend of both features
both features are represented
Multiple alleles
Gene has more than two allelic forms but only two can be present in a single organism as there’s only two chromosomes in a homologous pair.
