10/10/25, 1:15 AM BIOL 251 GENETICS EXAM 1 KEY
BIOL 251 GENETICS EXAM 1 KEY QUESTIONS AND
ANSWERS WITH COMPLETE SOLUTIONS | GRADED A+ |
NEW 2025-2026 UPDATE
Correct
Incorrect 00
BIOL 251 GENETICS EXAM 1
33 terms
Questions and answers
1/4
Awesome!
wild type female, what proportion of the progeny will be mutant males?
,10/10/25, 1:15 AM BIOL 251 GENETICS EXAM 1 KEY
Two gene loci, A and B, assort independently, and alleles A and B are
dominant over alleles a and b. What is the probability of producing an AB
gamete from an AaBb individual?
Two gene loci, A and B, assort independently, and alleles A and B are dominant over
alleles a and b. What is the probability of producing an AABB zygote from a cross
AaBb AaBb?
The probability of two or more independent events occurring together is calculated
by adding their independent probabilities
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2 of 34
Term
In peas, tall (T) is dominant to short (t). A homozygous tall plant is
crossed with a short plant. The F1 are self-fertilized to produce the F2.
Both tall and short plants appear in the F2. If the tall F2 are self-
fertilized, what types of offspring and proportions will be produced?
(2 points)
the tall and short traits assort independently of each other in this cross
, 10/10/25, 1:15 AM BIOL 251 GENETICS EXAM 1 KEY
1/3 of the tall F2 plants are TT, and 2/3 are Tt. The TT plants when selfed will
produce all tall plants. The Tt plants when selfed will produce 3 tall:1 short. If
all F2 plants produce an equal number of offspring, then 1/3 of the offspring
will be from TT plants and will be tall. Three-quarters of the plants from Tt will
be tall, but since only 2/3 of the F2 plants are Tt, this represents 2/3 3/4 = 6/12
= 1/2 of the total. Therefore, 1/3 + 1/2 = 5/6 will be tall. The remaining 1/6 of the
1/2 choafnfcsp
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Only the AABb genotype can produce Ab gametes, and the expected probability
of Ab gametes produced will be 1/2. Because the parent has an equal probability
(50%) of having either genotype (AaBB or AABb), the final probability of the parent
producing an Ab gamete is (1/2) (1/2) = 1/4 = 0.25 = 25%.
Don't know?
3 of 34
Term
at a single locus, a diploid individual may have more than 2 different
alleles
1/16 false
1/2 chance true
Don't know?
BIOL 251 GENETICS EXAM 1 KEY QUESTIONS AND
ANSWERS WITH COMPLETE SOLUTIONS | GRADED A+ |
NEW 2025-2026 UPDATE
Correct
Incorrect 00
BIOL 251 GENETICS EXAM 1
33 terms
Questions and answers
1/4
Awesome!
wild type female, what proportion of the progeny will be mutant males?
,10/10/25, 1:15 AM BIOL 251 GENETICS EXAM 1 KEY
Two gene loci, A and B, assort independently, and alleles A and B are
dominant over alleles a and b. What is the probability of producing an AB
gamete from an AaBb individual?
Two gene loci, A and B, assort independently, and alleles A and B are dominant over
alleles a and b. What is the probability of producing an AABB zygote from a cross
AaBb AaBb?
The probability of two or more independent events occurring together is calculated
by adding their independent probabilities
Don't know?
2 of 34
Term
In peas, tall (T) is dominant to short (t). A homozygous tall plant is
crossed with a short plant. The F1 are self-fertilized to produce the F2.
Both tall and short plants appear in the F2. If the tall F2 are self-
fertilized, what types of offspring and proportions will be produced?
(2 points)
the tall and short traits assort independently of each other in this cross
, 10/10/25, 1:15 AM BIOL 251 GENETICS EXAM 1 KEY
1/3 of the tall F2 plants are TT, and 2/3 are Tt. The TT plants when selfed will
produce all tall plants. The Tt plants when selfed will produce 3 tall:1 short. If
all F2 plants produce an equal number of offspring, then 1/3 of the offspring
will be from TT plants and will be tall. Three-quarters of the plants from Tt will
be tall, but since only 2/3 of the F2 plants are Tt, this represents 2/3 3/4 = 6/12
= 1/2 of the total. Therefore, 1/3 + 1/2 = 5/6 will be tall. The remaining 1/6 of the
1/2 choafnfcsp
e roinfgbw
eiinllgbae csahrorriet.r
Only the AABb genotype can produce Ab gametes, and the expected probability
of Ab gametes produced will be 1/2. Because the parent has an equal probability
(50%) of having either genotype (AaBB or AABb), the final probability of the parent
producing an Ab gamete is (1/2) (1/2) = 1/4 = 0.25 = 25%.
Don't know?
3 of 34
Term
at a single locus, a diploid individual may have more than 2 different
alleles
1/16 false
1/2 chance true
Don't know?
