Genetics
The study of inherited variation
Cells
The fundamental unit of life
RNA
A nucleic acid responsible for constucting proteins
DNA
The nucleic acid that makes up our genetic material
Gene
A sequence of DNA that instructs a cell to manufacture a specific protein
Chromosome
A continuous molecule of DNA and proteins
Genome
An organism's complete set of genetic constructions
Genomics
The study of the function and interactions between genes, DNA sequences, or genomes
Alelle
The variant of a gene
Mutation
A process by which an organism's DNA becomes altered
Gene pool
All genes in a given population
Dominant
The gene variant that is expressed when present in a single copy
Recessive
An alelle whose presence is masked by the presence of another alelle
Genotype
The combination of alleles in an organism, giving it specific traits or disorders
Phenotype
The expression of a gene in traits or sypmtoms
Multi-factorial Traits
Traits determined by several genes and the environment
Homozygous (homo)
Same
Heterozygous (hetero)
Different
Locus
Location of a gene on a chromosome
Wild Type
Most commonly observed genotype/phenotype
Monohybrid cross
Cross of a single trait
Dihybrid cross
Cross of 2 traits
Mendel's Law of Segregation
2 copies of a gene separate into different gametes (sex cells)
Mendel's Law of Independent Assortment
For 2 genes on different chromosomes, the inheritance of one does not influence the chance of inheriting the other
Pedigree
Chart that depicts relationships and transmission of inherited traits
Incomplete dominance
One trait is not expressed dominantly over the other (ex. snapdragons)
Epistasis
The interaction between 2 different genes that affects the expression of one over the other (2 or more genes influence a trait, but one gene overrides the other) (ex. albinism)
Co-dominance
Both dominant traits are expressed and no one trait is dominant over the other (ex. AB blood type)
Pleiotropy
A single gene is responsible for the control of several functions or multiple effects
Genetic heterogeneity
2 or more different genes produce the same phenotype (ex. Alzheimer's, Cystic Fibrosis)
Linkage
Genes on the same chromosome do NOT independently assort and do NOT produce Mendelian ratios
Crossing over
The exchange of information between chromosomes that leave them altered from their original state (exchange between homologs that mixes parental gene combos)
Recombinant
Non-parental allele combo in offspring
Sexual Identity
Determined by how genes are related to the sex chromosomes X, Y (includes sex chromosome make up, gender identity)
Autosomes
22 pairs of chromosomes
Heterogametic
Males have different gametes (both X and Y) and determine the sex of the child by the activation of the SRY gene
Homogametic
Females have two gametes of the same type (XX) and are absent of the SRY gene activation
SRY Gene
Encodes a transcription factor and is a protein that controls the expression of other genes.
Hemizygous
Males that have 1 set of X-linked genes
Genomic Imprinting
When a phenotype differs dependig on whether a gene is inherited from the mother or father (trait or illness could be more severe depending upon which parent transmitted the allele)
Polygenetic traits
Traits that are detemined by more than one gene
Polygenic pure traits
Traits not influenced by environment but is determined by more than one gene
Polygenic multifactorial traits
Traits/illnesses determined by several genes and the environment
Heritability
An estimate of the proportion of phenotypic variation in a group due to genetic differences that focuses on the genetic component of variation in traits that changes as the environment changes