Unit 5: Heredity Flashcards
DNA
Deoxyribonucleic acid; the molecule that carries genetic instructions for life.
Chromosome
A structure of nucleic acids and protein found in the nucleus, carrying genetic information in the form of genes
Gene
A segment of DNA that codes for a specific protein or function
Allele
Different versions of a gene
Genotype
The genetic makeup of an organism
Phenotype
The physical expression of a trait
Homozygous
Having two identical alleles for a particular gene
Heterozygous
Having two different alleles for a particular gene
Dominant
An allele that is always expressed if present
Recessivem
An allele that is only expressed when two copies are present
Mendel’s Law of Segregation
Each individual has two alleles for each gene, which separate during gamete formation
Mendel’s Law of Independent Assortment
Genes for different traits can segregate independently during the formation of gametes
Punnett Square
A diagram used to predict the outcome of a particular genetic cross
Test cross
A cross used to determine the genotype of an individual expressing a dominant trait
Monohybrid cross
A genetic cross involving one trait
Dihybrid cross
A genetic cross involving two traits
Pedigreem
A chart that shows the inheritance of a trait across generations
Sex-linked traitm
A trait associated with genes located on a sex chromosome, often the X chromosome
Incomplete dominance
A condition where neither allele is completely dominant, resulting in a blended phenotype
Codominancem
A condition where both alleles are fully expressed in the heterozygous state
Epistasis
When one gene affects the expression of another gene
Polygenic inheritance
Inheritance controlled by multiple genes, often resulting in a range of phenotypes.
