Inheritence Flashcards
Define gene
A sequence of bases on a dna molecule that codes for a polypeptide resulting in a characteristic
Define allele
Different version of a gene
Because the order of bases is slightly different
What is a genotype
The genetic constitution of an organism
What is phenotype
The expression of the genetic constitution of an organisms and its interactions with the environment
What is a dominant allele
Characteristic appears in the phenotype even when there’s only 1 copy
What is a recessive allele
Only appears in the phenotype if 2 copies are present
What is codominant
Alleles that are both expressed in the phototype
Define locus
The fixed position of a gene on a chromosome
What is a homozygote
Organism that carries 2 copies of the Same allele
What is a hétérozygote
Organism that carries 2 different alleles
What is a carrier
Person that carries an allele which is not expressed in the phenotype but can be passed onto offspring
What does diploid mean
2 alleles per gene
How many alleles do gametes have per gene
1
What is the phenotypic ratio
Ratio of different phenotypes in offspring
When is a characteristic said to be sex linked
When he allele that codes for it is on a sex chromosome (X or Y)
Why are most sex linked gene on the X chromosome
The X chromosome is bigger so carries more genes
Why are males more likely to show recessive phenotypes
Males have 1 X chromosome
So 1 allele for a sex linked allele
so can only express that 1 allele even if it’s recessive
What is the name for fault alleles of sex linked alleles
X linked disorders
