chapter 13 Flashcards
why is the white eyed phenotype always observed in males carrying the white eye allele
allele is located on x and males only have one x
in an organisms genome, autosomes are
all chromosomes other than sex chromosomes
what cellular process is responsible for genetic recomibination
crossing over
map distance between two genes is determined by
recombination frequency
how many map units separate two alleles if the recombination frequency is 0.07
0.07 *100 = 7 cM (centimorgan)
how does maternal inheritence of mitochondrial genes differ from sex linked genes
since mitochondria are inherited from the mother, males and females are equally affected
which of the following genotypes due to nondisjunction is lethal
xxx, xxy, oy, xo
oy
a recessive sex linked gene in humans leads to loss of sweat glands , a woman heterozygous for this will
show some areas of skin with and without sweat glands
like the calico cat
as real genetic distance increases, distance calculated by recombo frequency becomes
an underestimate due to multiple crossovers that cannot be scored
down syndrom is the result of a trisomy on chromosome 21 , why is this trisomy viable
chromosome 21 is a small chromsome with few genes so it does less to disrupt the genome
genes on the same chromosome can show independent assortment when________
they are far enough apart that odd numbers of crossovers are about equal to even
during spermatogenesis, a nondisjunction event that happens during second division would_____
be better than one during first division because only two of four meiotic products would be aneuploid
