Genetics Flashcards
Gregor Mendel
father of genetics (1822 - 1884)
first to document artificial pollination
- discovered the basic principles of hereditary through experiments with pea plants
What did Mendel learn from pea plants
discovered genes come in pairs and are distinct units, one from each parent
tracked the segregation of genes and their appearance in the offspring as dominant or recessive
Mendel’s 3 laws of inheritance
- law of segregation - only one of the two genes present in an organism
- law of independent assortment - genes do not influence each other with regards to sorting of alleles into gametes
- law of dominance - a heterozygote’s trait will conceal the presence of another trait for the same characteristic
Genotype
the genetic makeup of an organism eg. Tt
- used to refer to a single gene such as the genotype for eye colour
Phenotype
outward appearance
- the observable physical properties of an organism
eg. BLUE eyes, BROWN hair
Alleles
specific form of gene/variant form of gen
- an individual inherits two alleles for each gene, one from either parent
eg. brown hair
Genes
basic hereditary unit of physical and functional
- made up of DNA
- traits are determined by genes
Dominant
always visible/expressed
- masks the effect of a different variant of the same gene
represented by capital letters
eg. TT
Recessive
the unexpressed trait of the two alleles
- for it to be presented you need to copies
represented by small letters
eg. tt
Carrier
carries the trait (allele) and is capable of passing it onto future generations
- represented with one small and one big letter
eg. Tt - dominant trait is expressed as it overides the recessive trait
Homozygous
if two alleles are the same
eg. TT or tt
Heterozygous
if the two alleles are different
eg. Tt
