Mod 5 IQ 4 Flashcards
What is a gene
a section of DNA encoding a particular characteristics
Allele
alternative forms of a gene
Homozygous
identical alleles in a gene pair
Heterozygous
different alleles in a gene pair
Genotype
alleles present in an organism’s chromosomes
Phenotype
the outward appearance of an organism, determined by alleles expressed
Autosomal inheritance
when traits (alleles) are passed on the autosomes (i.eall chromosomes except for X and Y ) passed on both sexes with equal frequency
Sex-linkage inheritance
when traits (alleles ) are passed of the sex chromosomes (x or Y ). Traits are either X linked (ie present only on the X chromosome ) or Y linked present only on the Y chromosome
Autosomal dominant
when a trait is determined by the expression of a dominant allele. this means that the phenotype will always be expressed over the other allele inherited
Autosomal recessive inheritance
describes the pattern of inheritance where two recessive alleles are required to be inherited in order for a trait to be phenotypically expressed
Co-dominance
When both alleles in a gene pair are fully expressed
they are both fully expressed, resulting in a third possible phenotype
Incomplete dominance
when an allele for a certain trait is not completely expressed over its paired allele. This results in the creation of a third phenotype which is a blend version fo the both alleles
How is incomplete and co-dominance different
incomplete dominance is different from co-dominance because it is a result of alleles not being fully expressed
Multiple alleles
inheritance where three or more alleles exist for a single trait
SNPs (single nucleotide polymorphisms )
a change of a single nucleotide at a specific position on the genome. This may be a substitution (e.g, changing A for G), insertion (adding a new nucleotide), or deletion (removing a nucleotide )
