BSC2011L Quiz 2 Prelab Questions

If you were to do a χ2 test on the data, what would the expected value be for the individuals with white fur and blue eyes?

9.375

What is the expected phenotypic ratio in the F2 assuming independent assortment?

9:3:3:1

The allele for white hair in mice is autosomal recessive (b), while the allele for black hair is autosomal dominant (B). A white, female mouse mates with a black, male mouse. If the offspring are half black and half white, what are the possible genotypes for the black, male mouse?

Bb only

What type of data is analyzed using a chi-squared ( χ2 ) test?

Counts

What is the difference between an allele and a gene (locus)?

an allele is a particular version of a gene

Based on what you know, what kind of cross is being done here?

autosomal dihybrid cross

The allele for white hair in mice is autosomal recessive (b), while the allele for black hair is autosomal dominant (B). A white, female mouse mates with a black, male mouse. What are the possible genotypes for the white, female mouse?

bb only

You have guinea pigs from two pure breeding lines. One line has black fur and red eyes and the other line has white fur and blue eyes. When you cross them, all the F1 guinea pigs have black fur and blue eyes. When you cross the F1s to one another, you get a total of 50 F2 offspring. There are 31 with black fur and red eyes, 15 with white fur and blue eyes, 2 with white fur and red eyes, and 2 with black fur and blue eyes. There are approximately equal numbers of males and females in each phenotypic category. Which alleles are dominant?

black, blue

What does the law of segregation state?

only one allele per locus is present in each gamete

Why is it important to use individuals from pure breeding lines to start crosses?

to ensure the individuals are homozygous