Name: KEY UID: Exam code:
BSCI207: Principles of Biology III
Exam 2A – Fall 2025
Instructions:
• Put your name and UID on this first page. Sign the honor pledge.
• Read each question carefully and select the BEST answer(s).
• For multiple choice/fill in blank – put answers on answer sheet – last page
• For free response questions, answer in (and ONLY in) the space provided on the exam. Full credit
will only be given if you SHOW YOUR WORK.
• You have 50 minutes for this exam.
Please read and sign that you agree to follow the University of Maryland honor pledge:
“I understand my obligation to uphold the University Code of Academic Integrity and pledge I have not
received or given any unauthorized assistance on this academic exercise.”
Signature Date
Questions 1 – 18 of 49 points
Question 19 of 10 points
Question 20 of 8 points
Question 21 of 8 points
Total of 75 points
, 1. Eukaryotes have many key features that distinguish them from prokaryotes. Which one of the
following was a trait that early eukaryotes lost, but was later regained by photosynthetic plants?
a. The cell wall
b. A complex cytoskeleton
c. The mitochondria
d. The nuclear membrane
2. (4 pts) From the following list of organisms, which evolved (i) earliest in earth’s history? Which
evolved (ii) most recently?
a. Aerobic bacteria earliest
b. Aquatic plants
c. Terrestrial animals most recent
d. Terrestrial plants
3. We talked about alternation of generations in many plant life cycles. For the following organisms,
select whether (a) the gametophyte or (b) the sporophyte is the life stage that we typically observe in
nature.
i. Cherry tree b
ii. Moss a
4. In a woody plant, which one correctly describes the relative location of these different tissues?
a. The primary xylem is inside of the secondary xylem.
b. The primary phloem is inside of the secondary phloem.
c. The cork is inside of the secondary xylem.
d. The cork is inside of the secondary phloem.
5. (4 pts) Dogs are human’s best friend and we share many traits with them. For each trait, select the
state that applies to dogs.
i. Layers: a. monoblastic b. diploblastic c. triploblastic
ii. Symmetry a. none b. radial c. bilateral
iii. Gastrulation a. protostome b. deuterostome c. neither
iv. Segmentation a. yes b. no
6. The excavates are a protist group where some of the lineages lack mitochondria. Which piece of data
helps prove that all of the lineages originally had mitochondria?
a. the organisms have a nuclear membrane
b. the nuclear DNA contains sequences similar to alpha-proteobacteria
c. the nuclear DNA contains sequences similar to cyanobacteria
d. some of the organisms are photosynthetic
2
BSCI207: Principles of Biology III
Exam 2A – Fall 2025
Instructions:
• Put your name and UID on this first page. Sign the honor pledge.
• Read each question carefully and select the BEST answer(s).
• For multiple choice/fill in blank – put answers on answer sheet – last page
• For free response questions, answer in (and ONLY in) the space provided on the exam. Full credit
will only be given if you SHOW YOUR WORK.
• You have 50 minutes for this exam.
Please read and sign that you agree to follow the University of Maryland honor pledge:
“I understand my obligation to uphold the University Code of Academic Integrity and pledge I have not
received or given any unauthorized assistance on this academic exercise.”
Signature Date
Questions 1 – 18 of 49 points
Question 19 of 10 points
Question 20 of 8 points
Question 21 of 8 points
Total of 75 points
, 1. Eukaryotes have many key features that distinguish them from prokaryotes. Which one of the
following was a trait that early eukaryotes lost, but was later regained by photosynthetic plants?
a. The cell wall
b. A complex cytoskeleton
c. The mitochondria
d. The nuclear membrane
2. (4 pts) From the following list of organisms, which evolved (i) earliest in earth’s history? Which
evolved (ii) most recently?
a. Aerobic bacteria earliest
b. Aquatic plants
c. Terrestrial animals most recent
d. Terrestrial plants
3. We talked about alternation of generations in many plant life cycles. For the following organisms,
select whether (a) the gametophyte or (b) the sporophyte is the life stage that we typically observe in
nature.
i. Cherry tree b
ii. Moss a
4. In a woody plant, which one correctly describes the relative location of these different tissues?
a. The primary xylem is inside of the secondary xylem.
b. The primary phloem is inside of the secondary phloem.
c. The cork is inside of the secondary xylem.
d. The cork is inside of the secondary phloem.
5. (4 pts) Dogs are human’s best friend and we share many traits with them. For each trait, select the
state that applies to dogs.
i. Layers: a. monoblastic b. diploblastic c. triploblastic
ii. Symmetry a. none b. radial c. bilateral
iii. Gastrulation a. protostome b. deuterostome c. neither
iv. Segmentation a. yes b. no
6. The excavates are a protist group where some of the lineages lack mitochondria. Which piece of data
helps prove that all of the lineages originally had mitochondria?
a. the organisms have a nuclear membrane
b. the nuclear DNA contains sequences similar to alpha-proteobacteria
c. the nuclear DNA contains sequences similar to cyanobacteria
d. some of the organisms are photosynthetic
2
