SOL science prep 7th grade unit 6 Flashcards
study of how traits are inherited
Genetics
different form of gene
there are two of these for each gene (one from mom one from dad)
Allele
a train that will show if only one copy is present
Dominant trait/gene
a trait that will only show if two copys are present
Recessive Trait/Gene
same
ex: TT or tt
Homozygous
different
ex: Tt or Bb
Heterozygous
father of modern genetics
developed the principles of heredity by studying pea plants
Gregor Mendel
branch of biology that studys heredity (passing of characteristics from parents to offspring
Genetics
the different forms of the gene
ex: tall or short, freckles or no freckles
alleles (traits)
represented by an uppercase letter
when present, that trait will be expressed
Dominant Allele
represented by a lowercase letter
only expressed when none of the other type alleles are present
Recessive allele
organism has two dominat or two recessive alleles
Homozygous
organism has two different alleles
Heterozygous
letters
GENES
ex, BB, Bb, TT, Tt
Genotype
see physically
ex: purple flower, blonde hair
Phenotype
tool used to predict results of genetic cross
expressed as a ratio
each box filled with allele from top and left
Punnett Squares
a third phenotype appears when the genotype is heterosygous
blend of dominat and resessive
Incomplete Dominance
in heterozygous version both alleles expressed equally
two different capital letters
ex: sickle cells=SS
normal cells = NN
some of each = NS
Codominance
gene is attached to x chromosome only
cannot be found on y
disorders more common in boys
men cannot be carriers
Sex-Linked Traits
