/
LIFE SCIENCE 15: LIFE: CONCEPTS
' & ISSUES
MIDTERM EXAM
6 February 2025
J. Phelan
This exam is worth 150 points. You will have 120 minutes from the time you begin. Your
answer must fie on the page of the question. We will not grade any parts of answers
continued on the backs of pages. Please write legibly. Answers chat cannot be deciphered
will receive no credit.
Multiple-choice questions are each worth 3.5 points. There is only one correct answer for
each multiple-choice question. Shore answer questions are marked with their point value.
Multipl.e Choice Short Answer
total
�
(70 possible) problem 21 {J (20 possible)
problem 22 /7 (20 possible)
problem 23 20 (20 pos ible)
problem 24
�u (20 possible)
Tocala
, 1. ome gene , uch a the human ABO blood groups, have more than cwo alleles. For these genes:
a) dominance relationships are not possible. /\ t10 -;. A
b) a greater proportion of the individuals must be heterozygous than homozygous.
c) each individual possesses only cwo alleles.
d) it i possible (but rare) for an individual to be doubly heterozygous.
e) Both a) and c) are correct.
2. \,'hich of the following is true about mammals?
a) ex-linked dominant traits are more common among biological females than biological
males.
b) ex-linked dominant traits are more common among biological males than biological
females.
Sex-linked recessive traits are more common among biological females than biological
males. x"x" u ,c�''/
Sex-linked recessive traits are observed in biological males only.
one of the above are correct.
3. Sexual selection can lead to the evolution of traits such as the cumbersome antlers of a red deer or the
large fan of brightly colored feathers that male peacocks have. How can such traits evolve when they clearly
reduce the probability of survival for the individuals that possess them?
Because those traits are detrimental to survival, natural selection is in the process of
J'>
weeding them our. We see them because natural selection is slow and has not yet
completed the process of eliminating the alleles responsible for such traits.
b) Traits increase in frequency if they increase an organism's lifetime relative reproductive
success, regardless of their effect on survival.
Such traits arise from mutations and are maintained by genetic drift.
Such traits are produced by sexual selection, but never by natural selection.
The effects of natural selection can be countered by stronger effects of artificial selection
based on female mace choice.
4. In humans, what is the coefficient of relatedness for a pair of half-sisters?
a) 0.0625
b) 0.125
c) 0.25
d) 0.5
e) 0.75
S. Genetic drift: can occur in the absence of population bottlenecks or founder effects.
a) True
b) False
2
LIFE SCIENCE 15: LIFE: CONCEPTS
' & ISSUES
MIDTERM EXAM
6 February 2025
J. Phelan
This exam is worth 150 points. You will have 120 minutes from the time you begin. Your
answer must fie on the page of the question. We will not grade any parts of answers
continued on the backs of pages. Please write legibly. Answers chat cannot be deciphered
will receive no credit.
Multiple-choice questions are each worth 3.5 points. There is only one correct answer for
each multiple-choice question. Shore answer questions are marked with their point value.
Multipl.e Choice Short Answer
total
�
(70 possible) problem 21 {J (20 possible)
problem 22 /7 (20 possible)
problem 23 20 (20 pos ible)
problem 24
�u (20 possible)
Tocala
, 1. ome gene , uch a the human ABO blood groups, have more than cwo alleles. For these genes:
a) dominance relationships are not possible. /\ t10 -;. A
b) a greater proportion of the individuals must be heterozygous than homozygous.
c) each individual possesses only cwo alleles.
d) it i possible (but rare) for an individual to be doubly heterozygous.
e) Both a) and c) are correct.
2. \,'hich of the following is true about mammals?
a) ex-linked dominant traits are more common among biological females than biological
males.
b) ex-linked dominant traits are more common among biological males than biological
females.
Sex-linked recessive traits are more common among biological females than biological
males. x"x" u ,c�''/
Sex-linked recessive traits are observed in biological males only.
one of the above are correct.
3. Sexual selection can lead to the evolution of traits such as the cumbersome antlers of a red deer or the
large fan of brightly colored feathers that male peacocks have. How can such traits evolve when they clearly
reduce the probability of survival for the individuals that possess them?
Because those traits are detrimental to survival, natural selection is in the process of
J'>
weeding them our. We see them because natural selection is slow and has not yet
completed the process of eliminating the alleles responsible for such traits.
b) Traits increase in frequency if they increase an organism's lifetime relative reproductive
success, regardless of their effect on survival.
Such traits arise from mutations and are maintained by genetic drift.
Such traits are produced by sexual selection, but never by natural selection.
The effects of natural selection can be countered by stronger effects of artificial selection
based on female mace choice.
4. In humans, what is the coefficient of relatedness for a pair of half-sisters?
a) 0.0625
b) 0.125
c) 0.25
d) 0.5
e) 0.75
S. Genetic drift: can occur in the absence of population bottlenecks or founder effects.
a) True
b) False
2
