genetics and inheritance Flashcards
genotype
all the genetic makeup of the organism
genepool
ll the alleles within an interbreeding population
population
all the individuals of the same species that occupy the same area
phenotype
expression of its genetic constitution and its interaction with the environment
alleles
different versions of the same gene
locus
position of allele on the homologous chromosomes
homozygous
two copies of a gene
heterozygous
two copies of gene are different alleles
co-dominant alleles
equally expressed in the phenotype
gene pool definition
all of the alleles of all the genes of all the individuals in a population at a given time
allelic frequency
The number of times an allele occurs within a gene pool
Hardy-Weinberg principle predicts that:
the allelic frequencies from one generation to the next will remain constant
factors affecting the Hardy-Weinberg principle
-no migration
-no gene mutation
-no selection for a particular allele
-large population
-random mating
Hardy-Weinberg equations
P + q = 1.0
P2 + 2Pq + q2 = 1.0
monohybrid inheritance meaning
inheritance of a single gene which determines a single characteristic
monohybrid inheritance -Codominance
do not show a standard dominant/recessive relationship
superscript letters are used for the allele
monohybrid inheritance - multiple alleles
several genes in a population
dominance hierarchy
There was 850 fruit flies in a population.
510 fruit flies had the genotype W(H)W(N)
255 fruit flies had the genotype W(N)W(V)
85 fruit flies had the genotype W(V)W(V)
CALCULATE ALLELE FREQUENCY OF ALLELE W(V)
1700 alleles in frequency
2x85=170
1x255=255
255+170=425
424/1700
0.25
950 flies in population
frequency of W(V) allele. was 0.2
calculate the number of expected individuals with the genotype W(N)W(V)
2X0.2X0.8=0.32
0.32X950=
304
dominant characteristics rules
- affected offspring must have at least one affected parent
- unaffected parents only have unaffected offspring
- if both parents are affected but child is unaffected, both parents must be heterozygous
recessive characteristics
unaffected parents can have an affected offspring
sex linked characteristics
controlled by genes located on one of sex chromosomes
what are the male chromosomes
XY
what are the female characteristics
XX