2 MAXE · 171 OIB
◆ ◆
Department of Ecology & Evolutionary Biology
BIOLOGY
EXPLORING THE SCIENCE OF LIFE
BIO 171 Exam 2 — Ecology, Evolution & Climate Science
CO M P R E H E N S I V E E X A M I N AT I O N : C L I M AT E C H A N G E · C A R B O N CYC L E · E CO SYST E M S ·
E VO LU T I O N · V I R O LO G Y
INSTITUTION [UNCONFIRMED] — BIO 171 COURSE CODE BIO 171
General Biology
PROGRAM [INFERRED] — Associate / ACADEMIC YEAR
Bachelor of Science
EXAM TITLE BIO 171 Exam 2 — Ecology, TOTAL QUESTIONS 100 Questions
Evolution & Climate
COURSE TITLE General Biology II — Ecology & FORMAT Multiple Choice — Select the
Evolution Single Best Answer
EXAMINATION INSTRUCTIONS
▸ Select the single best answer for each question based on BIO 171 Exam 2 content.
▸ Questions cover climate change, carbon cycle, ecosystems, evolution, virology, and population ecology.
▸ Correct answers and detailed rationales provided for comprehensive exam preparation.
, SECTION I — BIO 171 EXAM 2: COMPREHENSIVE
Questions 1 – 100
EXAMINATION
1. What are the defining characteristics of Domain Eukarya?
A. Prokaryotic, unicellular, no nucleus, 4 billion years old
B. Eukaryotic, 2 billion years old, multicellular (some unicellular protists), has a nucleus and
membrane-bound organelles, includes plants, animals, and fungi
C. Prokaryotic, found only in extreme environments, extremophiles
D. Acellular, requires host cell to reproduce, contains RNA or DNA
CORRECT ANSWER B — Eukaryotic, 2 billion years old, multicellular (some unicellular protists),
has a nucleus and membrane-bound organelles, includes plants, animals,
and fungi
RATIONALE Domain Eukarya emerged approximately 2 billion years ago and is characterized
by cells with a true nucleus and membrane-bound organelles (mitochondria,
chloroplasts in some lineages). Eukarya includes multicellular kingdoms (plants,
animals, fungi) as well as unicellular protists. Eukarya is more closely related to
Archaea than Archaea and Bacteria are to each other. Key shared features: linear
chromosomes within a nucleus, mitosis, sexual reproduction in most lineages,
and complex cellular compartmentalization. The endosymbiosis theory explains
the origin of mitochondria and chloroplasts within eukaryotic cells from once
free-living bacteria.
,2. Which domains of life perform photosynthesis, and what proportion is done by
photosynthetic protists and cyanobacteria?
A. Only Domain Eukarya performs photosynthesis
B. Done by photoautotrophs in Bacteria and Eukarya; 50% of photosynthesis is done by
photosynthetic protists and cyanobacteria
C. Done by all three domains equally
D. Only cyanobacteria in Domain Bacteria perform photosynthesis
CORRECT ANSWER B — Done by photoautotrophs in Bacteria and Eukarya; 50% of
photosynthesis is done by photosynthetic protists and cyanobacteria
RATIONALE Photosynthesis is performed by organisms in two domains: Bacteria
(cyanobacteria, which originated oxygenic photosynthesis through
endosymbiosis giving rise to chloroplasts) and Eukarya (plants, algae, and
photosynthetic protists). Approximately 50% of global photosynthesis is carried
out by photosynthetic protists (phytoplankton) and cyanobacteria in aquatic
environments. The photosynthesis equation: sunlight + H₂O + CO₂ → glucose
(CH₂O) + O₂ converts light energy into chemical potential energy. Archaea do NOT
perform photosynthesis based on current data. This distribution highlights the
critical role of microbial photoautotrophs in global primary production and
oxygen generation.
, 3. What is Net Primary Production (NPP) and how is it calculated?
A. The total amount of chemical potential energy produced by photosynthesis
B. GPP minus cellular respiration — the chemical energy remaining after autotroph
respiration that is available to consumers
C. The energy lost as heat during cellular respiration
D. The total biomass of all organisms in an ecosystem
CORRECT ANSWER B — GPP minus cellular respiration — the chemical energy remaining after
autotroph respiration that is available to consumers
RATIONALE NPP = GPP − CR (cellular respiration by autotrophs). GPP is the total chemical
energy produced by photosynthesis; some of this energy is used by the primary
producers themselves for cellular respiration (generating ATP, releasing heat and
CO₂). The remaining energy — NPP — is what is available to heterotrophs
(consumers) when they eat autotroph biomass. NPP is a rate expressed as energy
or biomass per unit area per unit time (e.g., g C/m²/yr). NPP limits the number of
trophic levels in a food web because it represents the total energy entering the
ecosystem's food chain. All heterotrophs ultimately depend on NPP.