Skip to content
ExamPassoLog in

ASVAB Practice Test · General Science

ASVAB Practice Test: Life Science Concepts

Importance ★★★★☆ · 40% (estimate)

AI-written · Verified

Written by AI. Only units that passed a separate AI check (re-reading facts and numbers) are published. Tell us if you find a mistake.

Overview

This chapter covers living things, from the tiny cell up to whole ecosystems. You will review the parts of a cell, the main systems of the human body, basic nutrition, how traits pass from parents to children, and how living things depend on one another. Questions are usually short facts, so knowing the key words is the main job.

The cell is the basic unit of life. The nucleus holds the genetic material, DNA, and controls the cell. Mitochondria release energy from food for the cell to use. Plant cells also have a cell wall and chloroplasts, where photosynthesis uses sunlight to make sugar and give off oxygen.

In the body, red blood cells carry oxygen, white blood cells fight infection, and platelets help blood clot. The heart pumps blood, the lungs trade oxygen for carbon dioxide, and the small intestine absorbs most nutrients. Carbohydrates and fats give energy, while proteins build and repair tissue.

For a simple trait, you get two copies of a gene, one from each parent. A dominant trait shows when at least one dominant gene is present, while a recessive trait shows only when both genes are recessive. In an ecosystem, producers such as plants make their own food, consumers eat other living things, and decomposers break down dead material.

Key concepts

  • Cell parts

    The nucleus holds DNA and controls the cell. Mitochondria release energy. The cell membrane controls what goes in and out. Plant cells also have a cell wall and chloroplasts.

    Memory tipNucleus = control center. Mitochondria = power plant.

  • Photosynthesis

    The process in which plants use sunlight, water, and carbon dioxide to make sugar. Oxygen is given off as a by-product. It happens in the chloroplasts.

    Memory tipPlants take in carbon dioxide and give off oxygen.

  • Blood cells

    Red blood cells carry oxygen. White blood cells fight infection. Platelets help blood clot to stop bleeding.

    Memory tipRed = oxygen, white = defense, platelets = clotting.

  • Nutrients

    Carbohydrates are the body's main quick energy source. Fats store energy. Proteins build and repair tissue. Vitamins and minerals help body processes work.

    Memory tipCarbs for fuel, protein for building.

  • Dominant and recessive

    For a simple trait, you get two copies of a gene, one from each parent. A dominant gene shows its trait even with one copy. A recessive trait shows only when both copies are recessive.

    Memory tipRecessive needs two copies to show.

  • Food chain roles

    Producers (plants) make their own food. Consumers eat plants or animals. Herbivores eat plants, carnivores eat animals, and omnivores eat both. Decomposers, such as fungi and bacteria, break down dead matter.

    Memory tipMake it, eat it, or break it down.

Often tested

  • Mitochondria release energy for the cell.
  • Red blood cells carry oxygen; white blood cells fight germs.
  • Photosynthesis gives off oxygen.
  • Most nutrients are absorbed in the small intestine.
  • A recessive trait needs two recessive genes to show.

Easy to confuse: Plant cell vs. animal cell

PartPlant cellAnimal cell
Cell wallYesNo
ChloroplastsYesNo
Nucleus and mitochondriaYesYes

3 sample questions

Verified practice questions from this unit.

Practice questionReviewedGeneral Science › Life Science★★★★☆

Question 1. Which part of a cell releases energy from food so the cell can use it?

  1. ① Cell membrane
  2. ② Nucleus
  3. ③ Ribosome
  4. ④ Mitochondrion
▼ Show answer and explanation▲ Hide answer and explanation

Answer: ④ Mitochondrion

Key point: Mitochondria release energy for the cell

The mitochondrion is often called the "powerhouse" of the cell. It breaks down sugar from food and releases energy the cell can use.

Wrong choices

  • (A) Cell membrane: The cell membrane controls what goes in and out of the cell.
  • (B) Nucleus: The nucleus holds the cell's DNA and controls the cell.
  • (C) Ribosome: Ribosomes build proteins; they do not release energy from food.
Practice questionReviewedGeneral Science › Life Science★★★★☆

Question 2. Which blood cells carry oxygen from the lungs to the rest of the body?

  1. ① Red blood cells
  2. ② Nerve cells
  3. ③ Platelets
  4. ④ White blood cells
▼ Show answer and explanation▲ Hide answer and explanation

Answer: ① Red blood cells

Key point: Red blood cells carry oxygen

Red blood cells contain hemoglobin, a protein that picks up oxygen in the lungs and drops it off in the body's tissues.

Wrong choices

  • (B) Nerve cells: Nerve cells carry signals, not oxygen, and they are not blood cells.
  • (C) Platelets: Platelets help blood clot to stop bleeding.
  • (D) White blood cells: White blood cells fight infection; they do not carry oxygen.
Practice questionReviewedGeneral Science › Life Science★★★★☆

Question 3. Green plants make their own food using sunlight, water, and carbon dioxide. What is this process called?

  1. ① Digestion
  2. ② Transpiration
  3. ③ Photosynthesis
  4. ④ Respiration
▼ Show answer and explanation▲ Hide answer and explanation

Answer: ③ Photosynthesis

Key point: Photosynthesis: plants make food from light

In photosynthesis, a plant uses light energy to turn water and carbon dioxide into sugar. Oxygen is given off as a by-product.

Wrong choices

  • (A) Digestion: Digestion breaks down food in animals; plants do not make food this way.
  • (B) Transpiration: Transpiration is water vapor leaving a plant through its leaves.
  • (D) Respiration: Respiration breaks food down to release energy; it does not make food.
Practice 5 questions from this unit →