Introduction to Inheritance Flashcards
Gene
A length of DNA that codes for a polypeptide
Karyotype
All the chromosomes of a organism
Wild Type Gene
A naturally occurring form of a gene or the most common form of a gene
Mendelian Genetics
Discovered using pea plants
Controlled by a single locus on a inheritance pattern
Ratios of offspring can be predicted using a punnet square
Law of Segregation
During formation of gametes alleles for each gene segregate so gametes only form diploid organisms
Law of Independent Assortment
chromosomes assort randomly during meiosis to produce gametes with genetic variation
Law of Dominance
some alleles are dominant and some are recessive, organisms with at least one dominant allele will display the effect of the dominant allele
Autosomal Dominant
If allele present in genotype it will be present in the phenotype
50% chance of inheritance from heterozygous parents
Autosomal Recessive
Allele is only present in the phenotype if both alleles of the gene in the genotype are recessive
Sex Linked
Alelle for gene located on the sex chromosomes
Males XY
Females XX
if recessive gene located on X in males are more likely to show as only one X chromosome
Non Mendelian Inheritance
Only females pass on mitochondrial DNA as it is in hearted from the mothers egg.
This distorts phenotypic ratios
Co-Dominance
Relationship between two versions of a gene, the genes are linked so located on the same chromosome
Epistatis
One gene codes for a protein which masks or blocks the expression of another gene or production of protein
Results in unexpected phenotypic ratios
In eye colour HERC2 activates OCA2 producing a brown pigment, if no HERC2, OCA2 is not produced sports no pigment produced and it appears blue.
