Bio 1500 Test 3 Schul Exam Questions
and Answers 100% Pass
Explain how the relationship between phenotype and fitness determines the mode of
selection. - ✔✔Phenotype: observable traits
Fitness: ability to survive & reproduce in an environment
Directional Selection: fitness increases or decreases with trait value
Stabilizing selection: average valued traits have highest fitness
- Explain the outcome of different modes of selection on the mean value of a trait in a
population. - ✔✔Directional selection: mean value skewed towards traits with highest
fitness (longer horns on lizards survive more)
Stabilizing selection: mean value centered, bell-shaped curve (human birth weight)
- Identify several different selection pressures that could influence body size and
indicate the likely direction of phenotypic change in response to the pressure -
✔✔Sexual selection: competition among males favors large size
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, Selection for female fecundity (egg/number of offspring): large size
Selection for early reproduction: small size
Limited resource availability: small size
Predation: large size for predators, small size for prey
Locomotion: flight favors small size
Temperature: cold favors large size in mammals
- Describe the insect respiratory system - ✔✔-no blood in insects to transport oxygen
-individual trachea brings oxygen from environment directly to cells
*spiracles: openings to environment in insects
-oxygen and carbon dioxide travel through diffusion
- Recognize differences between human and insect respiratory systems - ✔✔Similarity:
both use trachea to transfer oxygen from environment and carbon dioxide to
environment, both use cellular respiration
Differences:
100% Pass Guarantee Sophia Bennett, All Rights Reserved © 2025 2
and Answers 100% Pass
Explain how the relationship between phenotype and fitness determines the mode of
selection. - ✔✔Phenotype: observable traits
Fitness: ability to survive & reproduce in an environment
Directional Selection: fitness increases or decreases with trait value
Stabilizing selection: average valued traits have highest fitness
- Explain the outcome of different modes of selection on the mean value of a trait in a
population. - ✔✔Directional selection: mean value skewed towards traits with highest
fitness (longer horns on lizards survive more)
Stabilizing selection: mean value centered, bell-shaped curve (human birth weight)
- Identify several different selection pressures that could influence body size and
indicate the likely direction of phenotypic change in response to the pressure -
✔✔Sexual selection: competition among males favors large size
100% Pass Guarantee Sophia Bennett, All Rights Reserved © 2025 1
, Selection for female fecundity (egg/number of offspring): large size
Selection for early reproduction: small size
Limited resource availability: small size
Predation: large size for predators, small size for prey
Locomotion: flight favors small size
Temperature: cold favors large size in mammals
- Describe the insect respiratory system - ✔✔-no blood in insects to transport oxygen
-individual trachea brings oxygen from environment directly to cells
*spiracles: openings to environment in insects
-oxygen and carbon dioxide travel through diffusion
- Recognize differences between human and insect respiratory systems - ✔✔Similarity:
both use trachea to transfer oxygen from environment and carbon dioxide to
environment, both use cellular respiration
Differences:
100% Pass Guarantee Sophia Bennett, All Rights Reserved © 2025 2
