Patterns of Inheritance Flashcards
Gene
Short sequence of DNA that gives rise to a protein/trait
Locus
Each gene has a particular location on a chromosome
What did Gregor Mendel discover?
Evidence of gene segregation, homologous chromosome are independently distributed and assorted during meiosis.
Alleles
Forms of a gene with a slightly different DNA sequence
Genotype
The particular set of alleles carried by an individual
Hybrid
The offspring of a cross between two individuals that breed true for different forms of a trait. (Heterozygous individual)
Difference between Homozygous and Heterozygous
Homozygous- 2 alleles that are the same (AA, aa)
Heterozygous-2 alleles that are different (Aa)
Phenotype
Physical appearance of a certain trait
Mendel’s Law of Segregation
During meiosis 2 genes segregate from each other and wind up in different gametes
Mendel’s Law of Independent Assortment
Genes located on a non-homologous chromosomes segregate independently of each other and give predictable F2 phenotypic ratio of 9:3:3:1
Co-dominance
Two non-identical alleles are both fully expressed in heterozygotes, so neither is dominant or recessive
Ex. Blood type
Multiple Allele Systems
Genes with 3 or more alleles in a population
Incomplete Dominance
Neither allele is not fully dominate over it’s partner
Ex. Snapdragon Color (red, pink,white)
Pleiotropy
A gene that influences multiple traits
Ex. Sickle Cell Anemia
Epistasis
Two or more gene products influence a trait..typically one gene product suppresses the effect of another
Ex. Color coat in dogs
Environment and Gene Expression
The environment affects the expression of many genes, which in turn affects phenotype–including behavioral traits
Genotype+environment-> phenotype
Continuous Variations
Traits with a range of small differences.
The more factors that influence a trait, the more the phenotype will be shown
Bell curve
When continuous phenotypes are divided into measurable categories and plotted as a bar chart, they form a bell-shapes curve
Complex variation in traits
- individuals of most species vary in some of their shared traits
- many traits (eye color) show a phenotypic range in variation
