unit 7, inheritance Flashcards
phenotype?
expression of genes, and its interaction within the environment
genotype?
genetic constitution of an organism
homozygous?
HH, hh
heterozygous?
Hh
recessive allele?
only expressed if no dominant is present
dominant allele?
will always be expressed in phenotype
monohybrid?
genetic inheritance cross of characteristics determined by one gene
dihybrid?
genetic inheritance cross for a characterisitc determined by two genes
codominant?
both alleles equally expressed in phenotype
sex linkage?
gene whose locus is on x chromosome
autosomal linkage?
genes located on same chromosome (not a sex chromosome)
epistasis?
a gene masks or modifies expression of a different gene at a different locus
what is dihybrid? where are the genes located on the chromosome
-inheritance of two pairs of alleles
-gene on one chromosome , one gene on other chromosome
what would the ratio of the phenotypes of the offspring be if two heterozygous parents mated?
9:3:3:1
what is a parental phenotype?
same phenotypes as parents
what are recombinant phenotypes?
-the result of recombination of chromosomes , in sexual reproduction
-e.g.) independent segregation
what are autosomes?
not sex chromosomes
what is autosomal linkage?
-both genes located on the same chromosome
for example) sweet peas have a chromosome with purple (P) and long (L) and another chromosome with white (p) and short (l)
example of sweet peas
how does a white long occur?
- crossing over in prophase 1 during meiosis
- this is unlikely to occur
how are genes on a chromosome less likely to split?
if they are close together on a chromosome
