ID#
LS107
GENETICS
Spring 2026
5/18/2026
MIDTERM II/Version A
Please circle your TA’s name
Moore 100: Giverny; Emily; and Aihui’s 1L
WG Young CS24: Lorenzo; and Aihui’s 2C
WG Young CS76: Young; and Katherine’s 2B
Haines 39: Peter; Courtney; and Katherine’s 2A
1. This exam has 10 pages. Before starting, make sure you have all the pages (including this cover
sheet).
2. All books, notes, and cell phones (turned off) must be put in zipped backpacks.
3. A simple or scientific calculator may be used.
4. There are 40 questions on the exam each worth 2.5 points.
5. You must write your last name, first name, student ID number, section number clearly and
bubble your test version on your scantron. Failure to do so will result in the loss of 5 points
from your exam total.
6. Taking exam at a wrong location will result in a loss of 5 points from your exam total.
7. Use pencils to fill out your scantron and erase any unwanted answers completely.
8. For True/False questions, mark A for True or B for False.
1
, Name:
Questions 1-6. A testcross of a dihybrid (original) plant AaBb gives 12% aaBb progeny.
1. The genotype of the dihybrid (original) plant is:
a. AaBb
b. Aabb
c. Ab/aB
d. AB/ab
e. None of the above
2. The map distance between A and B is:
a. 12 m.u.
b. 24 m.u.
c. 38 m.u.
d. 76 m.u.
e. None of these above
3. What percentage of the progeny will be either AaBb or aaBb from that testcross?
a. 12%
b. 24%
c. 50%
d. 76%
e. None of the above
4. If the dihybrid (original) plant is self-fertilized, what percentage of the progeny will be either
aabb or AABB?
a. less than or equal 10%
b. more than 10% but less than or equal 20%
c. more than 20% but less than or equal 30%
d. more than 30% but less than or equal 40%
e. more than 40%
5. If the dihybrid (original) plant is self-fertilized, what percentage of the progeny will be Ab/ab?
a. less than or equal 10%
b. more than 10% but less than or equal 20%
c. more than 20% but less than or equal 30%
d. more than 30% but less than or equal 40%
e. more than 40%
6. If the dihybrid (original) plant is self-fertilized, what percentage of the progeny will be AaBb?
a. less than or equal 10%
b. more than 10% but less than or equal 20%
c. more than 20% but less than or equal 30%
d. more than 30% but less than or equal 40%
e. more than 40%
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