Step-by-Step Guidance for College Biology Multiple Choice Questions

Study Guide - Smart Notes

Tailored notes based on your materials, expanded with key definitions, examples, and context.

Q1. A genetic disorder affects the function of the Golgi apparatus in human cells. Which of the following outcomes is MOST likely?

Background

Topic: Cell Organelles and Their Functions

This question tests your understanding of the role of the Golgi apparatus in eukaryotic cells, particularly in protein processing and trafficking.

Key Terms:

Golgi apparatus: Organelle responsible for modifying, sorting, and packaging proteins and lipids for secretion or delivery to other organelles.
Protein trafficking: The process of transporting proteins to their correct cellular destinations.

Step-by-Step Guidance

Recall the main function of the Golgi apparatus in the cell. What does it do with proteins after they are synthesized in the rough ER?
Consider what would happen if proteins are not properly packaged or sent to their correct destinations. How would this affect cell function?
Review the other answer choices and eliminate those that are not directly related to the Golgi apparatus's function (e.g., DNA replication, ATP production).

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Q2. A scientist observes a cell with a cell wall, a large central vacuole, and chloroplasts. This cell is placed in the dark for several days. What will likely happen to the cell’s energy production?

Background

Topic: Plant Cell Structure and Energy Metabolism

This question tests your understanding of how plant cells generate energy and how they adapt to changes in light availability.

Key Terms:

Chloroplasts: Organelles where photosynthesis occurs, converting light energy into chemical energy.
Mitochondria: Organelles responsible for cellular respiration and ATP production.
Photosynthesis: The process by which plants use sunlight to synthesize glucose.

Step-by-Step Guidance

Identify the organelles present and what processes they are involved in (e.g., chloroplasts for photosynthesis, mitochondria for respiration).
Consider what happens to photosynthesis when the cell is placed in the dark for several days.
Think about how the cell might compensate for the lack of photosynthesis in the absence of light.

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Q3. A mutation prevents a cell from producing functional lysosomes. What would be the MOST likely effect?

Background

Topic: Cell Organelles – Lysosomes

This question tests your knowledge of lysosome function, particularly in waste breakdown and recycling within the cell.

Key Terms:

Lysosome: Organelle containing digestive enzymes to break down waste, damaged organelles, and macromolecules.
Autophagy: The process by which cells degrade and recycle their own components.

Step-by-Step Guidance

Recall the main function of lysosomes in the cell.
Consider what would happen if the cell could not break down waste or damaged organelles.
Eliminate answer choices that do not relate to lysosome function (e.g., cell division, energy generation).

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Q4. Which of the following BEST explains why muscle cells have more mitochondria than skin cells?

Background

Topic: Cellular Respiration and Energy Demand

This question tests your understanding of the relationship between cell function and organelle abundance, specifically mitochondria.

Key Terms:

Mitochondria: The powerhouse of the cell, responsible for producing ATP through cellular respiration.
ATP: Adenosine triphosphate, the main energy currency of the cell.

Step-by-Step Guidance

Think about the primary function of muscle cells compared to skin cells.
Consider which cell type requires more energy and why.
Relate the energy demand to the number of mitochondria present in each cell type.

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Q5. A plant cell is placed in a hypertonic solution. What will happen to the cell?

Background

Topic: Osmosis and Tonicity in Plant Cells

This question tests your understanding of how plant cells respond to different external solute concentrations.

Key Terms:

Hypertonic solution: A solution with a higher solute concentration than the cell's cytoplasm.
Osmosis: The movement of water across a semipermeable membrane from low to high solute concentration.
Plasmolysis: The process where the cell membrane pulls away from the cell wall due to water loss.

Step-by-Step Guidance

Recall what happens to water movement when a cell is placed in a hypertonic solution.
Consider the structure of plant cells, including the cell wall and central vacuole.
Think about the physical changes that occur to the cell membrane and cell wall during water loss.

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Q6. A white blood cell engulfs a bacterium through endocytosis. Which organelle will most likely help destroy the bacterium?

Background

Topic: Immune Cell Function and Organelle Roles

This question tests your understanding of how cells use organelles to digest and destroy foreign invaders.

Key Terms:

Endocytosis: The process by which cells engulf external substances, forming a vesicle.
Lysosome: Organelle containing digestive enzymes that break down engulfed material.

Step-by-Step Guidance

Recall the process of endocytosis and what happens to the engulfed bacterium inside the cell.
Identify which organelle fuses with the vesicle containing the bacterium to digest it.
Eliminate organelles that do not have a digestive function.

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Q7. A bacterial cell is exposed to a chemical that selectively damages its plasma membrane. After exposure, the cell swells and bursts. What does this tell you about the external environment?

Background

Topic: Cell Membrane Integrity and Osmosis

This question tests your understanding of how the plasma membrane maintains cell integrity and how osmotic pressure affects cells.

Key Terms:

Plasma membrane: The semipermeable barrier that controls the movement of substances in and out of the cell.
Osmosis: Movement of water across a membrane from low to high solute concentration.
Hypotonic environment: An environment with lower solute concentration than the cell's cytoplasm, causing water to enter the cell.

Step-by-Step Guidance

Consider what happens to a cell when its plasma membrane is damaged.
Think about the direction of water movement if the external environment is hypotonic.
Relate the swelling and bursting of the cell to osmotic pressure differences.

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Q8. Which of the following BEST explains why most cells are small?

Background

Topic: Cell Size and Surface Area-to-Volume Ratio

This question tests your understanding of how cell size affects the efficiency of material exchange with the environment.

Key Terms:

Surface area-to-volume ratio: The amount of surface area per unit volume of a cell, affecting the rate of diffusion of materials.
Diffusion: The passive movement of molecules from high to low concentration.

Step-by-Step Guidance

Recall why cells need to efficiently exchange materials with their environment.
Consider how cell size affects the surface area-to-volume ratio.
Relate this ratio to the efficiency of nutrient uptake and waste removal.

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Q9. A red blood cell is placed in a solution and swells until it bursts. Which of the following best describes the solution?

Background

Topic: Osmosis and Tonicity in Animal Cells

This question tests your understanding of how animal cells respond to different external solute concentrations.

Key Terms:

Hypotonic solution: A solution with a lower solute concentration than the cell's cytoplasm.
Hemolysis: The bursting of red blood cells due to excessive water intake.

Step-by-Step Guidance

Recall what happens to animal cells in hypotonic, isotonic, and hypertonic solutions.
Consider the direction of water movement in each type of solution.
Relate the swelling and bursting of the red blood cell to the type of solution it was placed in.

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Q10. A cell is engineered to have defective carrier proteins for facilitated diffusion of glucose. Which of the following will likely occur?

Background

Topic: Membrane Transport Mechanisms

This question tests your understanding of facilitated diffusion and the role of carrier proteins in glucose transport.

Key Terms:

Facilitated diffusion: Passive transport of molecules across a membrane via specific carrier proteins.
Carrier proteins: Membrane proteins that assist in the transport of specific substances.
Glucose transport: The movement of glucose into cells, often requiring carrier proteins due to its polarity.

Step-by-Step Guidance

Recall how glucose normally enters cells and the role of carrier proteins in this process.
Consider what happens if these carrier proteins are defective or nonfunctional.
Eliminate answer choices that do not accurately describe glucose transport mechanisms.

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Q11. Which of the following characteristics distinguishes facilitated diffusion from active transport?

Background

Topic: Membrane Transport Mechanisms

This question tests your ability to differentiate between facilitated diffusion and active transport based on energy use and direction of movement.

Key Terms:

Facilitated diffusion: Passive movement of molecules down their concentration gradient via membrane proteins.
Active transport: Movement of molecules against their concentration gradient, requiring energy (ATP).

Step-by-Step Guidance

Recall the main differences between facilitated diffusion and active transport.
Consider whether each process requires energy and the direction of molecule movement.
Identify which answer choice best describes facilitated diffusion but not active transport.

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Q12. Heating a protein to 95°C causes it to lose function. Which level(s) of protein structure are MOST LIKELY disrupted by this treatment?

Background

Topic: Protein Structure and Denaturation

This question tests your understanding of the different levels of protein structure and how heat affects them.

Key Terms:

Primary structure: The sequence of amino acids in a protein.
Secondary structure: Local folding patterns (e.g., alpha helices, beta sheets) stabilized by hydrogen bonds.
Tertiary structure: The overall 3D shape of a single polypeptide chain.
Quaternary structure: The arrangement of multiple polypeptide subunits.
Denaturation: The loss of protein structure (and function) due to external stress like heat.

Step-by-Step Guidance

Recall which types of bonds and interactions stabilize each level of protein structure.
Consider which levels are most susceptible to disruption by heat (e.g., hydrogen bonds, hydrophobic interactions).
Determine whether the primary structure (peptide bonds) is affected by heat alone.

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Q13. Two amino acids in a protein's active site interact through hydrogen bonds. Which type of R groups are most likely involved?

Background

Topic: Protein Structure and Amino Acid Properties

This question tests your understanding of amino acid side chains (R groups) and their ability to form hydrogen bonds.

Key Terms:

R group (side chain): The variable group attached to the alpha carbon of an amino acid.
Hydrogen bond: A weak bond between a hydrogen atom and an electronegative atom (e.g., O or N).
Polar uncharged R groups: Side chains that can form hydrogen bonds due to the presence of electronegative atoms.

Step-by-Step Guidance

Recall which types of amino acid side chains can participate in hydrogen bonding.
Eliminate answer choices involving nonpolar or hydrophobic side chains, which do not form hydrogen bonds.
Identify which answer choice involves R groups capable of hydrogen bonding.

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Q14. In a eukaryotic cell, what would be the consequence of telomerase inactivity in germline cells over multiple generations?

Background

Topic: DNA Replication and Telomere Maintenance

This question tests your understanding of telomerase function and its importance in maintaining chromosome stability.

Key Terms:

Telomerase: An enzyme that adds repetitive DNA sequences to the ends of chromosomes (telomeres) to prevent shortening during replication.
Telomeres: Protective caps at the ends of chromosomes.
Genome instability: Increased likelihood of mutations and chromosomal abnormalities due to telomere shortening.

Step-by-Step Guidance

Recall the role of telomerase in germline cells and why it is important for long-term chromosome stability.
Consider what happens to telomeres during DNA replication in the absence of telomerase.
Think about the long-term consequences for the genome if telomeres become too short.

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Q15. During DNA replication, the template strand of a DNA molecule has the sequence 5’ - AATCGG - 3’. What will be the sequence of the newly synthesized complementary strand?

Background

Topic: DNA Replication and Base Pairing

This question tests your understanding of complementary base pairing and the directionality of DNA strands.

Key Terms:

Complementary base pairing: Adenine (A) pairs with Thymine (T), and Cytosine (C) pairs with Guanine (G).
Antiparallel: DNA strands run in opposite directions (5’ to 3’ and 3’ to 5’).

Step-by-Step Guidance

Write out the template strand and determine the complementary bases for each nucleotide.
Remember to write the complementary strand in the correct 3’ to 5’ or 5’ to 3’ direction, as specified in the answer choices.
Match your result to the answer choices, paying attention to strand directionality.

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Q16. During the initiation of transcription, which of the following events occurs first in eukaryotic cells?

Background

Topic: Transcription Initiation in Eukaryotes

This question tests your understanding of the sequence of events during the initiation of transcription.

Key Terms:

Promoter region: DNA sequence where transcription factors and RNA polymerase bind to initiate transcription.
General transcription factors: Proteins that help position RNA polymerase at the promoter.
RNA polymerase II: The enzyme that synthesizes mRNA in eukaryotes.

Step-by-Step Guidance

Recall the order of events in transcription initiation: binding of transcription factors, recruitment of RNA polymerase, and subsequent steps.
Identify which event must occur before RNA synthesis can begin.
Eliminate answer choices that occur after transcription initiation or are not part of the process.

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Q17. In a cell, a mutation prevents the removal of the 5’ cap from the pre-mRNA. What is the most likely consequence of this mutation?

Background

Topic: mRNA Processing in Eukaryotes

This question tests your understanding of the role of the 5’ cap in mRNA stability and translation.

Key Terms:

5’ cap: A modified guanine nucleotide added to the 5’ end of eukaryotic mRNA for stability and translation initiation.
mRNA stability: The lifespan of mRNA in the cytoplasm before degradation.
Translation: The process of synthesizing proteins from mRNA templates.

Step-by-Step Guidance

Recall the functions of the 5’ cap in mRNA processing and translation.
Consider what would happen if the 5’ cap could not be removed (i.e., it remains attached).
Eliminate answer choices that do not relate to the stability or translation of mRNA.

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Q18. A given DNA sequence is 5’ - ATGCGTAC - 3’. Which of the following is the correct mRNA sequence transcribed from this DNA template?

Background

Topic: Transcription and Base Pairing Rules

This question tests your understanding of how mRNA is synthesized from a DNA template, including base pairing and directionality.

Key Terms:

Transcription: The process of synthesizing RNA from a DNA template.
Base pairing: In RNA, adenine (A) pairs with uracil (U), and cytosine (C) pairs with guanine (G).

Step-by-Step Guidance

Write out the DNA template strand and determine the complementary RNA bases for each nucleotide.
Remember to use uracil (U) instead of thymine (T) in RNA.
Check the directionality of the mRNA strand (5’ to 3’).

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Q19. A point mutation in a gene leads to the substitution of a single nucleotide in the mRNA sequence, changing a codon from UGA (a stop codon) to UGG (tryptophan). What is the likely effect of this mutation on the protein?

Background

Topic: Genetic Code and Mutation Effects

This question tests your understanding of how point mutations can affect protein synthesis, especially when a stop codon is altered.

Key Terms:

Point mutation: A change in a single nucleotide in the DNA or RNA sequence.
Stop codon: A codon that signals the end of translation (e.g., UGA, UAA, UAG).
Missense mutation: A mutation that changes one amino acid to another.
Nonsense mutation: A mutation that introduces a premature stop codon.

Step-by-Step Guidance

Recall the function of stop codons in translation termination.
Consider what happens if a stop codon is mutated to code for an amino acid instead.
Think about how this change would affect the length of the resulting protein.

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Q20. A mutation in the coding region of a gene causes a single amino acid substitution in the resulting protein. This substitution does not alter the protein’s function. What type of mutation most likely caused this change?

Background

Topic: Types of Mutations and Their Effects

This question tests your understanding of the different types of mutations and their potential impact on protein function.

Key Terms:

Silent mutation: A mutation that does not change the amino acid sequence.
Missense mutation: A mutation that changes one amino acid to another.
Nonsense mutation: A mutation that introduces a premature stop codon.
Frameshift mutation: A mutation that shifts the reading frame, altering many amino acids.

Step-by-Step Guidance

Recall the definitions of each type of mutation listed in the answer choices.
Consider which type of mutation can result in an amino acid substitution without affecting protein function.
Eliminate mutations that would likely have a more drastic effect on the protein.

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Q21. In a mutation that causes a codon to change from AAA (lysine) to AGA (arginine), what type of mutation has occurred, and what is the possible effect on the protein?

Background

Topic: Types of Mutations and Their Effects

This question tests your understanding of missense, silent, nonsense, and frameshift mutations and their consequences.

Key Terms:

Missense mutation: A mutation that changes one amino acid to another.
Silent mutation: A mutation that does not change the amino acid sequence.
Nonsense mutation: A mutation that introduces a premature stop codon.
Frameshift mutation: A mutation that shifts the reading frame, altering many amino acids.

Step-by-Step Guidance

Identify the type of mutation based on the codon change (AAA to AGA).
Determine whether this change results in a different amino acid and what effect it might have on protein function.
Eliminate answer choices that do not match the described mutation or effect.

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Q22. A mutation occurs in a gene encoding a chromatin remodeling complex that prevents the complex from acetylating histones. What is the most likely consequence for gene expression in this case?

Background

Topic: Chromatin Structure and Gene Regulation

This question tests your understanding of how histone acetylation affects chromatin structure and gene expression.

Key Terms:

Histone acetylation: The addition of acetyl groups to histone proteins, usually associated with relaxed chromatin and increased gene expression.
Chromatin remodeling: The process of modifying chromatin structure to regulate gene accessibility.
Transcription: The process of copying DNA into RNA.

Step-by-Step Guidance

Recall the effect of histone acetylation on chromatin structure and gene expression.
Consider what would happen if histones cannot be acetylated due to a mutation.
Eliminate answer choices that do not match the expected effect on gene expression.

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Q23. In prokaryotic cells, transcription and translation are coupled. Which of the following best explains why this is possible?

Background

Topic: Prokaryotic Gene Expression

This question tests your understanding of the differences between prokaryotic and eukaryotic cells regarding gene expression.

Key Terms:

Transcription: Synthesis of RNA from a DNA template.
Translation: Synthesis of proteins from mRNA.
Prokaryotes: Cells lacking a nucleus, allowing simultaneous transcription and translation.

Step-by-Step Guidance

Recall the main structural difference between prokaryotic and eukaryotic cells regarding the presence of a nucleus.
Consider how the absence of a nucleus affects the timing and location of transcription and translation.
Eliminate answer choices that do not accurately describe prokaryotic cells.

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Q24. A researcher is testing the hypothesis that increased light intensity accelerates plant growth. She sets up two groups of plants: one group is exposed to normal light, and the other is exposed to increased light intensity. After two weeks, she measures the height of the plants. Which aspect of the experiment is the dependent variable?

Background

Topic: Experimental Design – Variables

This question tests your understanding of independent and dependent variables in scientific experiments.

Key Terms:

Dependent variable: The variable that is measured or observed in an experiment.
Independent variable: The variable that is manipulated by the researcher.

Step-by-Step Guidance

Identify what the researcher is changing (independent variable) and what is being measured (dependent variable).
Review the answer choices and match them to the definitions of independent and dependent variables.
Eliminate choices that are not measured outcomes.

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Q25. A scientist conducts an experiment to determine if a new drug improves memory function in mice. In the experiment, one group of mice is given the drug, while another group is given a placebo. The researcher measures the memory performance of both groups after a week. Which of the following is the experimental control group?

Background

Topic: Experimental Controls

This question tests your understanding of control groups in experimental design.

Key Terms:

Control group: The group in an experiment that does not receive the experimental treatment and is used for comparison.
Placebo: An inactive substance given to the control group to mimic the experimental conditions.

Step-by-Step Guidance

Identify which group receives the experimental treatment and which does not.
Recall the purpose of a control group in an experiment.
Match the answer choices to the definition of a control group.

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Q26. In an experiment testing the effect of different soil types on plant growth, the researcher observes that plants grown in soil A show better growth than plants grown in soil B. The researcher concludes that soil A is superior for plant growth. Which of the following is a limitation of this conclusion?

Background

Topic: Experimental Design – Limitations and Confounding Variables

This question tests your understanding of experimental limitations and the importance of controlling variables.

Key Terms:

Confounding variable: An outside factor that can affect the outcome of an experiment.
Control group: A group used as a baseline for comparison.
Sample size: The number of subjects or replicates in an experiment.

Step-by-Step Guidance

Consider what factors could limit the validity of the researcher's conclusion.
Think about whether all variables except soil type were controlled.
Eliminate answer choices that do not represent valid limitations.

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Q27. A scientist is conducting an experiment to test whether a new antibiotic is effective against a specific bacterial strain. She tests the antibiotic on bacterial cultures grown in petri dishes and measures the diameter of the clear zone around the antibiotic-treated areas, indicating bacterial inhibition. What would be the most appropriate control for this experiment?

Background

Topic: Experimental Controls in Microbiology

This question tests your understanding of the importance of controls in experiments testing the effectiveness of treatments.

Key Terms:

Control group: A group that does not receive the experimental treatment, used for comparison.
Placebo: An inactive substance used as a control.
Zone of inhibition: The area around an antibiotic where bacteria do not grow.

Step-by-Step Guidance

Identify what the experimental group is (bacteria treated with the antibiotic).
Consider what a proper control would look like in this context (e.g., bacteria not exposed to the antibiotic or exposed to a placebo).
Eliminate answer choices that do not serve as a baseline for comparison.

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Q28. A researcher designs an experiment to test the effect of a new fertilizer on plant height. The researcher uses a single type of plant and provides equal amounts of water and sunlight to all plants. After several weeks, the researcher measures the height of the plants in both the control and experimental groups. What is the independent variable in this experiment?

Background

Topic: Experimental Design – Variables

This question tests your understanding of independent and dependent variables in scientific experiments.

Key Terms:

Independent variable: The variable that is manipulated by the researcher.
Dependent variable: The variable that is measured or observed.

Step-by-Step Guidance

Identify what the researcher is changing in the experiment (the independent variable).
Determine what is being measured as the outcome (the dependent variable).
Match the answer choices to the definitions of independent and dependent variables.

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Q29. In regions where malaria is prevalent, individuals who are heterozygous for sickle cell anemia (carriers) have a selective advantage over both homozygous normal individuals and homozygous sickle cell individuals. Why does this occur?

Background

Topic: Genetics and Natural Selection

This question tests your understanding of heterozygote advantage and its role in maintaining genetic diversity in populations.

Key Terms:

Heterozygote advantage: A situation where individuals with two different alleles have higher fitness than those with two identical alleles.
Sickle cell anemia: A genetic disorder affecting hemoglobin structure.
Malaria resistance: The ability to survive and reproduce in regions with malaria due to genetic traits.

Step-by-Step Guidance

Recall how the sickle cell allele affects malaria resistance and sickle cell disease symptoms.
Consider the fitness of heterozygotes compared to both types of homozygotes in malaria-endemic regions.
Eliminate answer choices that do not accurately describe the selective advantage of heterozygotes.

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Q30. In a population where sickle cell anemia is common, a new genetic mutation occurs that results in complete resistance to malaria. How might this new mutation affect the frequency of the sickle cell allele in the population over time?

Background

Topic: Evolutionary Genetics and Allele Frequency

This question tests your understanding of how new mutations and selective pressures can alter allele frequencies in populations.

Key Terms:

Allele frequency: The proportion of a specific allele among all alleles in a population.
Selective advantage: A genetic trait that increases an individual's fitness in a particular environment.
Mutation: A change in the DNA sequence that can introduce new traits.

Step-by-Step Guidance

Consider why the sickle cell allele is common in malaria-endemic regions (heterozygote advantage).
Think about how a new mutation conferring complete malaria resistance would affect the selective advantage of the sickle cell allele.
Predict how the frequency of the sickle cell allele would change if the new mutation spreads in the population.

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Q31. In a population of organisms, a beneficial allele increases in frequency over generations. What is the most likely cause of this increase?

Background

Topic: Evolution and Natural Selection

This question tests your understanding of the mechanisms that drive changes in allele frequencies in populations.

Key Terms:

Natural selection: The process by which individuals with advantageous traits reproduce more successfully, increasing the frequency of those traits.
Genetic drift: Random changes in allele frequencies, especially in small populations.
Mutation: The source of new genetic variation.
Gene flow: Movement of alleles between populations.

Step-by-Step Guidance

Recall the main mechanisms that can change allele frequencies in a population.
Consider which mechanism would most likely cause a beneficial allele to increase in frequency over generations.
Eliminate mechanisms that do not specifically favor beneficial alleles.