BIOLOGY 101 EXAM 4 2026 CLIMATE
CHANGE AND HUMAN IMPACT ON
ECOSYSTEMS REVIEW QUESTIONS
SOLUTIONS PROFESSIONAL GUIDE
◉ Fossils (older)
Answer: deeper, less radioactive isotopes
◉ Fossils (younger)
Answer: top, more radioactive isotopes
◉ What fossils show us in general:
Answer: 1) Oldest rock layers lack fossils of modern life. 2) Life has
changed over time (# species, types). 3) Life began in oceans,
gradually spread to land. 4) Current organisms resemble earlier
ones with changes.
◉ Biogeography shows?
Answer: 1) Earlier organisms gave rise to current organisms. 2)
Continent positions have changed over time. 3) Climates have
changed as the continents moved.
, ◉ What is an example of biogeography?
Answer: The appearance of fossils from the same species spread
over the continents of south America, Africa and Australia
◉ Comparative anatomy is similar to comparative embryology
because...
Answer: Both methods study body structure, just at different stages
of life
◉ divergent evolution
Answer: when two or more species sharing a common ancestor
become more different over time
◉ homologous structures
Answer: Structures in different species that are similar because of
common ancestry.
◉ vestigal structures
Answer: a structure in a present day organism that no longer serves
its natural purpose; found in common ancestor, structures left over
(ex: tailbone)
◉ convergent evolution
Answer: start with different ancestors, leads to analogous structures
CHANGE AND HUMAN IMPACT ON
ECOSYSTEMS REVIEW QUESTIONS
SOLUTIONS PROFESSIONAL GUIDE
◉ Fossils (older)
Answer: deeper, less radioactive isotopes
◉ Fossils (younger)
Answer: top, more radioactive isotopes
◉ What fossils show us in general:
Answer: 1) Oldest rock layers lack fossils of modern life. 2) Life has
changed over time (# species, types). 3) Life began in oceans,
gradually spread to land. 4) Current organisms resemble earlier
ones with changes.
◉ Biogeography shows?
Answer: 1) Earlier organisms gave rise to current organisms. 2)
Continent positions have changed over time. 3) Climates have
changed as the continents moved.
, ◉ What is an example of biogeography?
Answer: The appearance of fossils from the same species spread
over the continents of south America, Africa and Australia
◉ Comparative anatomy is similar to comparative embryology
because...
Answer: Both methods study body structure, just at different stages
of life
◉ divergent evolution
Answer: when two or more species sharing a common ancestor
become more different over time
◉ homologous structures
Answer: Structures in different species that are similar because of
common ancestry.
◉ vestigal structures
Answer: a structure in a present day organism that no longer serves
its natural purpose; found in common ancestor, structures left over
(ex: tailbone)
◉ convergent evolution
Answer: start with different ancestors, leads to analogous structures
