Bio 251 Final Exam
(2026-2027 Edition)
Questions with 100% Correct
Answers and Rationales | Latest
Update | Grade A+
,What is evolution? Evolution is the change in the genetic makeup of a population over generations,
leading to new species over time.
Who was Charles Darwin and what did he discover? He was a naturalist who proposed natural selection: individuals with
advantageous traits survive and reproduce, causing species to change over time.
What are the four mechanisms of evolution? Natural selection, mutation, gene flow, genetic drift
Is there evidence for evolution? Yes: fossils, comparative anatomy, embryology, biogeography, DNA evidence,
and observed evolution like antibiotic resistance.
What is ecology? The study of how organisms interact with each other and their environment.
What are biotic factors? Living components of an ecosystem: plants, animals, bacteria, fungi.
What are abiotic factors? Non-living components: sunlight, water, temperature, air, soil, climate.
What are density-dependent factors? Factors that increase with population size: competition, disease, predation,
limited food/space.
What are density-independent factors? Factors that affect populations regardless of size: fires, floods, pollution,
temperature changes.
What is carrying capacity? The maximum population size an environment can sustainably support.
How fast is the human population growing? By about 80 million people per year.
How have humans increased their carrying capacity? Through medicine, agriculture, sanitation, technology, and global transport of
resources.
What is an ecological footprint? The amount of land, water, and energy a person or population uses, including the
waste they produce.
What is biodiversity? The variety of life on Earth, which supports stable and resilient ecosystems.
Why is biodiversity higher in the tropics? Stable warm climate, high productivity, and long periods without ice ages allow
more species to develop.
Why is human impact so profound? Humans use many resources, alter habitats, create pollution, and change
ecosystems on a global scale.
, What is the Grasshopper Effect? Pollutants evaporate in warm areas, travel long distances, and condense in
colder regions like the Arctic.
What is bioaccumulation? The buildup of toxins in an organism's tissues over time. Concentration increases
up the food chain
What happens when excessive nutrients enter algal blooms, oxygen depletion, dead zones, and massive die-offs of aquatic life.
waterways?
How do humans interfere with biodiversity? Habitat destruction, Deforestation, pollution, overhunting/fishing, invasive
species, agriculture, fragmentation, and climate change.
What is acid rain and what causes it? Rain made acidic by sulfide and nitride from burning fossil fuels; these chemicals
form acids when mixed with water vapor.
What is the greenhouse effect? The trapping of heat by greenhouse gases such as CO2, methane, and Nitrous
Oxide, worsened human activities.
What is the Kyoto Protocol? An international agreement aimed at reducing global greenhouse gas emissions.
Why is the ozone layer important? It blocks harmful UV radiation that can cause cancer, cataracts, and ecosystem
damage. (Also ozone on the ground is not safe to breathe, too much O3)
What depletes the ozone layer? CFCs (chlorofluorocarbons), which release chlorine atoms that destroy ozone
molecules.
Why is plastic pollution harmful? It causes ingestion and entanglement, produces microplastics, releases toxins,
and disrupts ecosystems.
Measures to help preserve biodiversity Protected areas, restoration projects, sustainable fishing/forestry, wildlife
corridors, pollution controls, emission reductions, and banning harmful
chemicals.
Anatomy study of the structure of an organism
Physiology the study of the function of an organism's structural equipment
Connective tissues binds to and supports other tissues
Extracellular matrix the material between each cell in connective tissues
Epithelial tissues covers surfaces of your body, lines organs and cavities
(2026-2027 Edition)
Questions with 100% Correct
Answers and Rationales | Latest
Update | Grade A+
,What is evolution? Evolution is the change in the genetic makeup of a population over generations,
leading to new species over time.
Who was Charles Darwin and what did he discover? He was a naturalist who proposed natural selection: individuals with
advantageous traits survive and reproduce, causing species to change over time.
What are the four mechanisms of evolution? Natural selection, mutation, gene flow, genetic drift
Is there evidence for evolution? Yes: fossils, comparative anatomy, embryology, biogeography, DNA evidence,
and observed evolution like antibiotic resistance.
What is ecology? The study of how organisms interact with each other and their environment.
What are biotic factors? Living components of an ecosystem: plants, animals, bacteria, fungi.
What are abiotic factors? Non-living components: sunlight, water, temperature, air, soil, climate.
What are density-dependent factors? Factors that increase with population size: competition, disease, predation,
limited food/space.
What are density-independent factors? Factors that affect populations regardless of size: fires, floods, pollution,
temperature changes.
What is carrying capacity? The maximum population size an environment can sustainably support.
How fast is the human population growing? By about 80 million people per year.
How have humans increased their carrying capacity? Through medicine, agriculture, sanitation, technology, and global transport of
resources.
What is an ecological footprint? The amount of land, water, and energy a person or population uses, including the
waste they produce.
What is biodiversity? The variety of life on Earth, which supports stable and resilient ecosystems.
Why is biodiversity higher in the tropics? Stable warm climate, high productivity, and long periods without ice ages allow
more species to develop.
Why is human impact so profound? Humans use many resources, alter habitats, create pollution, and change
ecosystems on a global scale.
, What is the Grasshopper Effect? Pollutants evaporate in warm areas, travel long distances, and condense in
colder regions like the Arctic.
What is bioaccumulation? The buildup of toxins in an organism's tissues over time. Concentration increases
up the food chain
What happens when excessive nutrients enter algal blooms, oxygen depletion, dead zones, and massive die-offs of aquatic life.
waterways?
How do humans interfere with biodiversity? Habitat destruction, Deforestation, pollution, overhunting/fishing, invasive
species, agriculture, fragmentation, and climate change.
What is acid rain and what causes it? Rain made acidic by sulfide and nitride from burning fossil fuels; these chemicals
form acids when mixed with water vapor.
What is the greenhouse effect? The trapping of heat by greenhouse gases such as CO2, methane, and Nitrous
Oxide, worsened human activities.
What is the Kyoto Protocol? An international agreement aimed at reducing global greenhouse gas emissions.
Why is the ozone layer important? It blocks harmful UV radiation that can cause cancer, cataracts, and ecosystem
damage. (Also ozone on the ground is not safe to breathe, too much O3)
What depletes the ozone layer? CFCs (chlorofluorocarbons), which release chlorine atoms that destroy ozone
molecules.
Why is plastic pollution harmful? It causes ingestion and entanglement, produces microplastics, releases toxins,
and disrupts ecosystems.
Measures to help preserve biodiversity Protected areas, restoration projects, sustainable fishing/forestry, wildlife
corridors, pollution controls, emission reductions, and banning harmful
chemicals.
Anatomy study of the structure of an organism
Physiology the study of the function of an organism's structural equipment
Connective tissues binds to and supports other tissues
Extracellular matrix the material between each cell in connective tissues
Epithelial tissues covers surfaces of your body, lines organs and cavities
