Inheritance Flashcards
Gene
Section of DNA that codes for proteins
Allele
Different version of same gene - 1v from each homologous chromosome.
Found at the same locus on each chromosome
Locus
Location on a gene
Inheritance
Ärftlighet. Hur olika saker ärvs från orgaksmer
Genotype
Combination of all alleles in an individuals genome
Phenotype
The traits that are expressed as a result of the genotype and interactions with their environment .
May be expressed as a visible trait, behaviour or biochemical reactions in the body.
Trait
Characteristic of an organism that is passed from parent to child
Homozygous
When alleles in a gene pair are the same the individual’s homozygous for that trait.
Heterozygous
When alleles in a gene pair are the different the individual’s heterozygous for that trait
Dominant allele
Expressed by capital letters. Will be expressed if an individual is homozygous dominant or heterozygous.
Recessive allele
Expressed by lowercase letters. Is not expressed unless an individual is homozygous recessive.
Polygenic inheritance
Traits that are affected by Multiple genes. Ex skin color determined by 8 genes+ sunlight. (Genes + environment)
Punnett square
A model for determining the ratio of geno and phenotypes
Pleiotropy
Describes the effect of a gene on several traits. Ex mutation on gene 12 can lead to PKU.
1 gene ➡️ multiple traits
Epistasis
Describes how 1 gene affects other genes expressions. Ex labradors coat color are determined by 2 genes; amount of pigment (gB) & whether or not gB is expressed.
Incomplete dominance
Occurs when one allele’s not dominant over the other. Both contribute equally to express a phenotype that is a mix of the original traits.
Ex red flower + white ➡️ pink
Co-dominance
When both alleles in a genepair are expressed. Phenotype is a combination of both where each are clearly expressed. Red flower + white ➡️ some red petals some white petals.
Ratio
Räknas ut via mathematical analyses. Each version of a trait is expressed in different particular rations (amounts)
Karyotype
An individual’s complete set of chromosomes. Syftar oxå till den bild över kromosomerna antal o utseende som kan framställas när fotograferar celler i mitosens metaphase. (Gen paren, 23 st)
Autosomal
En kromosom som inte är en könskromosom, dvs alla utom X & Y.
➡️ 22 par av 23 är autosomal
Law of segregation
Each gamete only contains 1 allele for each gene; each parent can only pass on 1 version of each gene. (During meiosis 1)
Law of independent asortment
Alleles are segregated (divided) randomly. (Meiosis 1)
Exception: alleles located in the same chromosome can’t be randomly separated.
Law of dominance
Recessive alleles are masked (not expressed) by dominant alleles.
Exception: some alleles are co-dominant or incompletely dominant
