TEAS Science · Practice Question

    Genetics: TEAS Practice Question with Answer & Explanation

    An original TEAS 7-style science practice question, written for nursing-school applicants — with a full breakdown of every answer choice.

    Question

    If two heterozygous parents have genotype Aa, what is the probability that an offspring will have genotype aa?

    • A.0%
    • B.25%
      Correct
    • C.50%
    • D.75%

    Correct answer: B. A Punnett square for Aa × Aa produces AA, Aa, Aa, and aa, so one of four outcomes is aa.

    Why B is correct

    A Punnett square for Aa × Aa produces AA, Aa, Aa, and aa, so one of four outcomes is aa.

    How to solve this TEAS question

    Identify what the question is testing, eliminate choices that conflict with the relevant rule or evidence, and then select the option that directly answers the prompt.

    Review the alternatives

    The other choices do not satisfy the scientific fact, mathematical operation, language rule, or reading evidence tested by this question. Always compare each option with the exact wording of the prompt before deciding.

    Quick study tip: Write each parent's possible gametes before completing a Punnett square.

    Ready to practice more TEAS Science questions?

    Test yourself on the full TEAS science question bank — with instant scoring, explanations, and progress tracking.

    Take a free TEAS Science quiz See all Science questions

    More TEAS Science practice questions

    Science
    Phase Changes and Equilibrium fluid dynamics
    In a closed system, equilibrium is reached when the rate of evaporation equals the rate of condensation, maintaining constant levels of each phase.
    Science
    Nervous System Functions
    Motor (efferent) neurons carry impulses away from the central nervous system to muscles or glands to trigger a response.
    Science
    Integumentary System Excretion
    Urea is a nitrogenous waste product formed from protein breakdown that is excreted in small amounts through sweat glands.
    Science
    Macromolecules and Growth
    Amino acids are the building blocks of proteins, which are essential for structural repair, enzyme production, and tissue growth in the body.
    Science
    Scientific Reasoning and Hypotheses
    When new data contradicts an old hypothesis, the hypothesis must be revised to include the new findings. Choice B reflects both the harm and the help.
    Science
    Cellular Energy Processes
    Photosynthesis is the process that converts solar energy into chemical energy, storing it in the bonds of glucose for later use by the cell.

    Learn more about TEAS Science

    Review the wider topic with these closely related study guides and practice resources.

    TEAS Science Practice Guide

    Review anatomy, biology, chemistry, and scientific reasoning.

    Anatomy & Physiology Practice Test

    Practice body-system questions with detailed rationales.

    TEAS Science Flashcards

    Strengthen recall across major science concepts.

    TEAS Science Cheat Sheet

    Review high-yield science facts and relationships.