Lab 6 Flashcards
Are females xx or xy?
xx
are males xx or xy?
xy
What is a karyotype?
a photograph of the chromosomes of an actively dividing cell, showing the number, shape, and size.
how many pairs of autosomal chromosomes do people have?
22
How many pairs of sex chromosomes do people have?
1
What is turner syndrome?
it is when an x or a y is missing
missing a sex chromosome
What is down syndrome?
trisomy 21
3 21 chromosomes
What is Klinefelter’s?
2 x chromosomes and 1 y
Does sex-linked mean they are related to sex?
no
What chromosome are sex-linked genes found on?
x chromosome.
Are males or females more likely to have a sex-linked trait?
males
Do heterozygous females display a sex linked trait?
no. they are called carriers.
What deficiency causes red-green color blindness?
deutan (can’t see red) and protan (can’t see green)
What are polygenic traits?
phenotypic traits that involve contributions from the alleles of many genes at multiple locations and on separate chromosomes.
What are 4 examples of polygenic traits?
IQ, human height, skin pigmentation, total yields of crop varieties, production level of milk in cattle.
What is the distance between two genes measured in?
map units
Hoe do you find map units (% recombination)?
total # of recombinants
___________________ x 100
total # of offspring
What numbers are considered the recombinants?
The two lowest numbers
How are recombinant gametes formed?
When crossing over occurs
What does a graph for a polygenic trait look like?
an upside down “U”
