Chapter 15 - Genotypes and Phenotypes Flashcards
define phenotype
the physical expression of a genotype and the alleles corresponding for a particular trait. a phenotype can be modified by environmental factors
define genotype
the genetic information, regarding an organisms specific trait, that is contained in the organisms DNA`
for every chromosome in the cell there is a…
homologous partner (1 from mum, 1 from dad)
define homozygous
a genotype where the 2 alleles are the same
define heterozygous
a genotype where the 2 alleles are different
define allele
an alternative form of a gene
define codominance
the alleles in the genotype both equally contribute to the corresponding phenotype.
what is discontinuous variation
where individuals fall into a number of distinct categories. there is a discontinuity between groups
what is continuous variation
where there are no distinct categories for individuals to be sorted into. The variation across a population is endless.
what are polygenic traits
a polygenic trait is a trait controlled by at least 2 polygenes. the alleles in the polygenes equally contribute to the phenotype.
a pedigree square represents a
male
a pedigree circle represents a
female
a pedigree coloured shape represents
an affected person
what are the 4 modes of inheritance
autosomal dominant
autosomal recessive
sex linked dominant
sex linked recessive
if an affected person has parents that are both unaffected the trait is…
recessive
