BIO 340 Cogbooks
Module 3 & 4 Exam
Questions and Complete
Solutions Graded A+
Denning [Date] [Course title]
, In mating b/w two individuals that are heterozygous for a recessive lethal allele that is expressed in
utero, what genotypic ratio (homo dom, hete, homo reces) would you expect to observe in the
offspring? - Correct Ans: 1:2:0
In rats, gene B produces black coat color if the genotype is B-, but black pigment is not produced if the
genotype is bb. At an independent locus, gene D produces yellow pigment if the genotype is D-, but no
pigment is produced when the genotype is dd. If neither pigment is produced, coat color is cream. The
genotype of parents of litters with the following phenotype distribution 3 brown, 3 yellow, 1 black, 1
cream is? - Correct Ans: BbDd x bbDd
In rats, gene B produces black coat color if the genotype is B-, but black pigment is not produced if the
genotype is bb. At an independent locus, gene D produces yellow pigment if the genotype is D-, but no
pigment is produced when the genotype is dd. If neither pigment is produced, coat color is cream. The
phenotype of parents of litters with the following phenotype distribution 3 brown, 3 yellow, 1 black, 1
cream is? - Correct Ans: brown and yellow
if genes are often on *different* chromosome, is it true that 50% of gametes produced by a double
heterozygous individual will be recombinant? - Correct Ans: True
if a species has n=4 chromosomes. Genes on the *same* chromosome have a *maximum*
recombination recombination rate of 50%? - Correct Ans: true
If a species has n=4 chromosomes. Genes on the *same* chromosome have a *minimum*
recombination recombination rate of 0%? - Correct Ans: true
You are studying two linked genes that influence vine height and fruit color in squash. Yellow color is
dominant over green, and tall height is dominant over short. You get the following numbers of offspring
from your testcross: 198 Yellow, 192 Short Green, 54 Tall Green, and 56 Short Yellow. Which offspring
are recombinants? - Correct Ans: Tall green and short yellow
You are studying two linked genes that influence vine height and fruit color in squash. Yellow color is
dominant over green, and tall height is dominant over short. You get the following numbers of offspring
from your testcross: 198 Yellow, 192 Short Green, 54 Tall Green, and 56 Short Yellow. What is the
distance between these genes? - Correct Ans: 22 cM
Module 3 & 4 Exam
Questions and Complete
Solutions Graded A+
Denning [Date] [Course title]
, In mating b/w two individuals that are heterozygous for a recessive lethal allele that is expressed in
utero, what genotypic ratio (homo dom, hete, homo reces) would you expect to observe in the
offspring? - Correct Ans: 1:2:0
In rats, gene B produces black coat color if the genotype is B-, but black pigment is not produced if the
genotype is bb. At an independent locus, gene D produces yellow pigment if the genotype is D-, but no
pigment is produced when the genotype is dd. If neither pigment is produced, coat color is cream. The
genotype of parents of litters with the following phenotype distribution 3 brown, 3 yellow, 1 black, 1
cream is? - Correct Ans: BbDd x bbDd
In rats, gene B produces black coat color if the genotype is B-, but black pigment is not produced if the
genotype is bb. At an independent locus, gene D produces yellow pigment if the genotype is D-, but no
pigment is produced when the genotype is dd. If neither pigment is produced, coat color is cream. The
phenotype of parents of litters with the following phenotype distribution 3 brown, 3 yellow, 1 black, 1
cream is? - Correct Ans: brown and yellow
if genes are often on *different* chromosome, is it true that 50% of gametes produced by a double
heterozygous individual will be recombinant? - Correct Ans: True
if a species has n=4 chromosomes. Genes on the *same* chromosome have a *maximum*
recombination recombination rate of 50%? - Correct Ans: true
If a species has n=4 chromosomes. Genes on the *same* chromosome have a *minimum*
recombination recombination rate of 0%? - Correct Ans: true
You are studying two linked genes that influence vine height and fruit color in squash. Yellow color is
dominant over green, and tall height is dominant over short. You get the following numbers of offspring
from your testcross: 198 Yellow, 192 Short Green, 54 Tall Green, and 56 Short Yellow. Which offspring
are recombinants? - Correct Ans: Tall green and short yellow
You are studying two linked genes that influence vine height and fruit color in squash. Yellow color is
dominant over green, and tall height is dominant over short. You get the following numbers of offspring
from your testcross: 198 Yellow, 192 Short Green, 54 Tall Green, and 56 Short Yellow. What is the
distance between these genes? - Correct Ans: 22 cM
