BIOL 117 FINAL UPDATED ACTUAL PRACTICE
QUESTIONS WITH DETAILED EXPLANATIONS
2026
◉ What is the difference between a hypothesis and a theory?
Answer: -Theory is not considered to be true
-Theory can be backed by evidence
-Hypothesis is testable
◉ Charles Darwin
Answer: English naturalist
-father of modern evolutionary theory
-Wrote "Origin of Species"
◉ Inheritance of acquired characteristics
Answer: -Lamarckian belief that changes in an individual's life
would be passed along to their offspring
-i.e. giraffe stretched neck to reach trees and offspring would have
long necks
◉ transitional forms
,Answer: fossils that connect ancestral species with their
descendants through a series of tiny steps i.e. pakicetus is an
ancestor to whales
◉ Vestigial traits with examples
Answer: Structures in organisms that serve no purpose and are
residual from ancestor species i.e. wings on flightless birds, hind leg
bones in fish
◉ Homology
Answer: anatomical commonalities between species indicating a
common ancestor i.e. arm bones in humans, fish, reptiles, etc.
◉ Phylogeny
Answer: origin of the division of a line of species
evolutionary history of a group or organisms that shows ancestor-
descendent relationships
◉ Developmental homology
Answer: similarities of embryonic traits between several species
◉ Genetic Homology
Answer: similarity in dna of different species
,◉ natural selection-necessary factors
Answer: 1. more individuals are produced than can survive
2.population variation exists
3. traits are genetically heritable
4. offspring better suited to the environment will survive
◉ Selection operates on what (what is being selected)
Answer: selection operates on the physical characteristics-
phenotype
◉ What do Allele frequency changes occur in
Answer: individuals
◉ Biological Fitness
Answer: ability of an individual to produce offspring compared to
individuals of the same species
◉ Biological species concept- defining a species
Answer:
◉ prezygotic isolating mechanisms
, Answer: when individuals of different species are prevented from
mating
Temporal-different mating times
Habitats
Behavioral, i.e. different mating calls
Mechanical-structurally incompatible
genetic-gametes wont fuse
◉ Postzygotic isolating mechanism
Answer: individuals of different species mate but the hybrid
produced has low fitness and may not survive or produce offspring
inviability-embryos may not develop properly
fertility-hybrids cannot produce offspring
i.e. mules from horse and donkey
◉ Allopatric speciation
Answer: speciation due to geographic separation, when a population
becomes isolated by a physical barrier mutations arise and are
reproductively isolated if the species come into contact i.e. squirrels
on either side of grand canyon
◉ Vicariance
Answer: the physical separation of a species
QUESTIONS WITH DETAILED EXPLANATIONS
2026
◉ What is the difference between a hypothesis and a theory?
Answer: -Theory is not considered to be true
-Theory can be backed by evidence
-Hypothesis is testable
◉ Charles Darwin
Answer: English naturalist
-father of modern evolutionary theory
-Wrote "Origin of Species"
◉ Inheritance of acquired characteristics
Answer: -Lamarckian belief that changes in an individual's life
would be passed along to their offspring
-i.e. giraffe stretched neck to reach trees and offspring would have
long necks
◉ transitional forms
,Answer: fossils that connect ancestral species with their
descendants through a series of tiny steps i.e. pakicetus is an
ancestor to whales
◉ Vestigial traits with examples
Answer: Structures in organisms that serve no purpose and are
residual from ancestor species i.e. wings on flightless birds, hind leg
bones in fish
◉ Homology
Answer: anatomical commonalities between species indicating a
common ancestor i.e. arm bones in humans, fish, reptiles, etc.
◉ Phylogeny
Answer: origin of the division of a line of species
evolutionary history of a group or organisms that shows ancestor-
descendent relationships
◉ Developmental homology
Answer: similarities of embryonic traits between several species
◉ Genetic Homology
Answer: similarity in dna of different species
,◉ natural selection-necessary factors
Answer: 1. more individuals are produced than can survive
2.population variation exists
3. traits are genetically heritable
4. offspring better suited to the environment will survive
◉ Selection operates on what (what is being selected)
Answer: selection operates on the physical characteristics-
phenotype
◉ What do Allele frequency changes occur in
Answer: individuals
◉ Biological Fitness
Answer: ability of an individual to produce offspring compared to
individuals of the same species
◉ Biological species concept- defining a species
Answer:
◉ prezygotic isolating mechanisms
, Answer: when individuals of different species are prevented from
mating
Temporal-different mating times
Habitats
Behavioral, i.e. different mating calls
Mechanical-structurally incompatible
genetic-gametes wont fuse
◉ Postzygotic isolating mechanism
Answer: individuals of different species mate but the hybrid
produced has low fitness and may not survive or produce offspring
inviability-embryos may not develop properly
fertility-hybrids cannot produce offspring
i.e. mules from horse and donkey
◉ Allopatric speciation
Answer: speciation due to geographic separation, when a population
becomes isolated by a physical barrier mutations arise and are
reproductively isolated if the species come into contact i.e. squirrels
on either side of grand canyon
◉ Vicariance
Answer: the physical separation of a species
