Bio 325
BIO 325-Exam 1 Study Guide Questions and
Answers 2025 Graded A+
Proximate/Mechanism -Correct Answers ✔-How do modern day animals carry out
their function?
Ultimate/Origin -Correct Answers ✔-Why do modern day animals possess the
features that they do?
What are the main subjects to consider in the study of animal physiology? -Correct
Answers ✔-1. Animals/Humans
2. Their Environment
3. Evolutionary Processes
Define homeostasis. -Correct Answers ✔-Maintaining a stable internal
environment
Define allometry. -Correct Answers ✔-The study of how various traits change with
body size.
Define evolution. -Correct Answers ✔-The change in gene frequencies over time
in a population.
What are the four factors of evolution? -Correct Answers ✔-1. Mutation
2. Migration = movement of individuals
3. Natural selection = not random, selective force
4. Genetic drift = Random shifts in gene frequencies over time
What is a trait? -Correct Answers ✔-An adaptation if it has become frequent in a
population.
Bio 325
, Bio 325
True or False: Every trait that an animal possess has evolved (via mutation, genetic
drift, natural selection). -Correct Answers ✔-True.
True or False: Because a trait exists, it means that it is adaptive. -Correct Answers
✔-False.
What are Darwin's 4 postulates? -Correct Answers ✔-1.Variation: Individuals
within species are variable.
2.Inheritance: Some of these variations are passed on to offspring.
3.Differential survival: In every generation, more offspring are produced than can
survive.
4.Extinction: The survival and reproduction of individuals is not random.
Individuals who survive and reproduce are those with the most favorable
variation...
What is fitness? -Correct Answers ✔-A measure of how adaptive a trait might be;
The ability of an individual to survive and reproduce.
Determine which mother has a higher fitness:
Mother A lives 8 years, becomes sexually mature within 1 year, and produces 3
babies a year.
Mother B lives 4 years, becomes sexually mature within 1 year, and produces 7
babies a year. -Correct Answers ✔-Both have the same level of fitness.
(Life span - sexual maturity) x offspring
What are the 6 key aspects of natural selection and how it operates? -Correct
Answers ✔-1. Populations evolve over time as natural selection acts on
individuals.
2. Natural selection acts on phenotypes
3. Natural selection is "backward-looking"
4. Natural selection acts on existing traits
5. Evolution by natural selection is not random
6. Natural selection acts on individual, not groups
Bio 325
BIO 325-Exam 1 Study Guide Questions and
Answers 2025 Graded A+
Proximate/Mechanism -Correct Answers ✔-How do modern day animals carry out
their function?
Ultimate/Origin -Correct Answers ✔-Why do modern day animals possess the
features that they do?
What are the main subjects to consider in the study of animal physiology? -Correct
Answers ✔-1. Animals/Humans
2. Their Environment
3. Evolutionary Processes
Define homeostasis. -Correct Answers ✔-Maintaining a stable internal
environment
Define allometry. -Correct Answers ✔-The study of how various traits change with
body size.
Define evolution. -Correct Answers ✔-The change in gene frequencies over time
in a population.
What are the four factors of evolution? -Correct Answers ✔-1. Mutation
2. Migration = movement of individuals
3. Natural selection = not random, selective force
4. Genetic drift = Random shifts in gene frequencies over time
What is a trait? -Correct Answers ✔-An adaptation if it has become frequent in a
population.
Bio 325
, Bio 325
True or False: Every trait that an animal possess has evolved (via mutation, genetic
drift, natural selection). -Correct Answers ✔-True.
True or False: Because a trait exists, it means that it is adaptive. -Correct Answers
✔-False.
What are Darwin's 4 postulates? -Correct Answers ✔-1.Variation: Individuals
within species are variable.
2.Inheritance: Some of these variations are passed on to offspring.
3.Differential survival: In every generation, more offspring are produced than can
survive.
4.Extinction: The survival and reproduction of individuals is not random.
Individuals who survive and reproduce are those with the most favorable
variation...
What is fitness? -Correct Answers ✔-A measure of how adaptive a trait might be;
The ability of an individual to survive and reproduce.
Determine which mother has a higher fitness:
Mother A lives 8 years, becomes sexually mature within 1 year, and produces 3
babies a year.
Mother B lives 4 years, becomes sexually mature within 1 year, and produces 7
babies a year. -Correct Answers ✔-Both have the same level of fitness.
(Life span - sexual maturity) x offspring
What are the 6 key aspects of natural selection and how it operates? -Correct
Answers ✔-1. Populations evolve over time as natural selection acts on
individuals.
2. Natural selection acts on phenotypes
3. Natural selection is "backward-looking"
4. Natural selection acts on existing traits
5. Evolution by natural selection is not random
6. Natural selection acts on individual, not groups
Bio 325
