U.1 (Genetics🧬): Heredity and Trait Inheritance vocab

Pure lineage

a homogeneous line of descent; same genetic makeup

Cross

the successful mating of two organisms from distinct genetic lines

P Generation

the parent plants used in a cross

Filal Generations F1, F2

F1 - offspring of P generation cross

F2 - offpspring of an F1 generation cross

Monohybrid cross

a cross designed to study the inheritance of only one trait

Dominant Allele

the allele that if present, is always expressed

Recessive Allele

the allele that is expressed only if it’s not in the presence of the dominant allele, that is, of the individual is homozygous for the recessive allele

“Law of Segregation”

a scientific law statinng that

1. Organisms inherit two copies of genes, one from each parent

2. Organisms donate only one copy of each gene to their gametes because the genes seperate during gamete formation

Genotype

the genetic makeup on an individual

Phenotype

an individual’s outward appearance with respect to a specific characteristic

Homozygous

an individual that carries two of the same alleles for a given characteristic

Heterozygous

an individual that carries two different alleles for a given characteristic

Punnet Square

a tool used for determining the probability of a single offspring having a particular genotype

Test cross

a cross used ton determine the genotype of an individual expressing a dominant trait

Dihybrid cross

a cross that involves two genes, each consisting of heterozygous alleles

“Law of Independent Assortment”

if genes are located on seperate chromosomes, they will be inherited independently of one another

“Product Law”

the probability of two independent random events both occuring is the product of an individual events, probability

“Chromosomal Theory of Inheritance”

theory states that individual genes are found at specific locations on particular chromosomes

Pedigree

a diagram of an individual’s ancestors used in human genetics

Autosomal Transmission

traits that are carried and transmitted via autosomes

Autosomal Dominant

a way a genetic trait or condition can be passed down from ONE parent to the child

Autosomal Recessive

a way a genetic trait or condition can be passed down from BOTH parents to the child

Incomplete Dominance

when the dominant trait does not completely mask the recessive trait

Codominance

a situation where both alleles are expressed fully to produce offspring with a third phenotype

Heterozygous Advantage

describes the case in which the heterozygote genotype has a higher relative fitness than either the homozygote dominant or homozygote recessuve genotype

Continuous Variation

characteristics like weight or height, which change gradually

Polygenic Trait

a characteristic such as skin colour that is influenced by two or more genes

Related Genes

genes carried on the same chromosome

Sex-Related (X-Linked) Trait

characteristics (or traits) that are influenced by genes carried on the sex chromosomes