Honors Biology Spring Final Study Guide – Step-by-Step Guidance

Q1. Define Darwin’s Theory of Evolution. What is natural selection? What is a heritable trait?

Background

Topic: Evolutionary Biology

This question tests your understanding of the foundational concepts of evolution, specifically Darwin's theory, the mechanism of natural selection, and the concept of heritable traits.

Key Terms:

• Darwin’s Theory of Evolution: The scientific explanation for how species change over time through natural selection.

• Natural Selection: The process by which organisms with traits better suited to their environment tend to survive and reproduce more successfully.

• Heritable Trait: A characteristic that can be passed from parents to offspring through genes.

Step-by-Step Guidance

1. Start by summarizing Darwin’s main idea: species evolve over time due to changes in heritable traits.

2. Explain what natural selection is and how it acts as the mechanism for evolution. Consider how environmental pressures influence which traits are advantageous.

3. Define what makes a trait heritable and why heritability is essential for evolution by natural selection to occur.

4. Think of an example where a heritable trait provides an advantage in a specific environment, leading to increased survival or reproduction.

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Q2. What is homology and what is its relevance to evolution? Give two examples of homologous structures.

Background

Topic: Comparative Anatomy & Evolution

This question focuses on the concept of homology, which provides evidence for common ancestry among species.

Key Terms:

• Homology: Similarity in structures due to shared ancestry.

• Homologous Structures: Anatomical features in different species that originated from a common ancestor.

Step-by-Step Guidance

1. Define homology in the context of evolutionary biology.

2. Explain why homologous structures are important evidence for evolution.

3. Think of two examples of homologous structures (e.g., forelimbs of mammals) and describe how they are similar in structure but may serve different functions.

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Q3. What is microevolution and how does it occur? What are the sources of microevolution? How are new alleles “made”? What are the different types of causes for microevolution?

Background

Topic: Population Genetics

This question examines your understanding of small-scale evolutionary changes within populations and the mechanisms that drive these changes.

Key Terms and Concepts:

• Microevolution: Changes in allele frequencies within a population over time.

• Allele: Different forms of a gene.

• Mutation: The original source of new alleles.

• Genetic Drift, Gene Flow, Natural Selection: Mechanisms that cause microevolution.

Step-by-Step Guidance

1. Define microevolution and distinguish it from macroevolution.

2. List and briefly describe the main sources of microevolution (mutation, gene flow, genetic drift, natural selection).

3. Explain how new alleles arise (focus on mutation as the ultimate source).

4. Describe how each mechanism (mutation, gene flow, genetic drift, natural selection) can change allele frequencies in a population.

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Q4. How are species defined? Name the four ways and give an example.

Background

Topic: Speciation & Species Concepts

This question tests your knowledge of the different ways biologists define a species and the importance of each definition.

Key Terms:

• Biological Species Concept

• Morphological Species Concept

• Ecological Species Concept

• Phylogenetic Species Concept

Step-by-Step Guidance

1. List the four main species concepts used in biology.

2. Briefly define each concept.

3. Think of an example organism that fits each concept (e.g., horses and donkeys for biological species concept).

4. Consider why multiple definitions are necessary in biology.

Try solving on your own before revealing the answer!