Lecture 7 Flashcards
Homozygous
The two alleles at a particular locus are the same. Eg. Pp purple allele and white allele
Heterozygous
The two alleles at a particular locus are different.
Dominant
An allele that is fully expressed in a heterozygote. (Controls what the trait would actually look like). Dominance has to do with the expression of the allele in the heterozygote.
Recessive
An allele that is not expressed at all in the heterozygote.
Genotype
The specific alleles that an organism has.
Phenotype
The character that the organism has (due to genotype and environment) ex tanning (the sun changing traits, the env affecting traits).
Pea plant
diploid, they have two alleles at each locus. Like the flower color locus. The purple allele (dominant) and the white (recessive) allele.
Phenotype
observable trait. Genotype: invisible trait.
Are animals haploid or diploid?
Diploid
What is to be known of the parents to predict the offspring traits?
Knowing the genotypes of the parents will give an idea of the offspring
Codominant
Both alleles are fully expressed in the heterozygote.
Incomplete dominance
It means no dominance, where both alleles contribute partially to the phenotype in the heterozygote. They both influence the phenotype but not completely. Example: pink flower with allele for red flower and allele for white flower.
Pleiotropy
Refers to a situation where a genotype at a single locus influences more than one trait. Eg. osteogenesis imperfecta: at a single locus there are two known alleles and on of the alleles is a recessive allele.
Dihybrid Cross
Hybridization experiment in which the inheritance of two traits is studied. eg . pea color and pea shape are two different traits and each of the traits are determined at different locus.
The two competing hypothesis
the hypothesis of dependant vs independent assortment.
Dependent assortment: The allele inherited at one locus is dependent on the allele inherited at the other locus.
