Study 4 quizzes free—no account needed. 3 more quizzes to explore.

HESI A2 Biology Set 2

Question 1 of 35

Which organelle modifies, sorts, and packages proteins for transport?

Select one answer.

Review all questions in this quiz

HESI A2 Biology Set 2 Practice Questions

Review these HESI A2 Biology Set 2 nursing practice questions with answer choices and explanations.

Question 1

Which organelle modifies, sorts, and packages proteins for transport?

  1. Ribosome
  2. Golgi apparatus
  3. Nucleus
  4. Centrosome
View answer and explanation

Correct answer:

  1. Golgi apparatus

Explanation: The Golgi apparatus processes proteins and packages them into vesicles for delivery.

Question 2

Which organelle contains digestive enzymes that break down worn-out cell components?

  1. Chloroplast
  2. Nucleolus
  3. Lysosome
  4. Ribosome
View answer and explanation

Correct answer:

  1. Lysosome

Explanation: Lysosomes digest cellular waste, damaged organelles, and some foreign material.

Question 3

Where is most of the DNA located in a typical human cell?

  1. Nucleus
  2. Cell membrane
  3. Golgi apparatus
  4. Cytosol
View answer and explanation

Correct answer:

  1. Nucleus

Explanation: Most human cellular DNA is stored in the nucleus, with a small amount in mitochondria.

Question 4

Which structure gives rough endoplasmic reticulum its rough appearance?

  1. Cilia
  2. Vesicles
  3. Flagella
  4. Ribosomes
View answer and explanation

Correct answer:

  1. Ribosomes

Explanation: Ribosomes attached to its surface make rough endoplasmic reticulum appear rough.

Question 5

What is a major function of smooth endoplasmic reticulum?

  1. Chromosome separation
  2. Lipid synthesis
  3. Protein translation
  4. Glucose breakdown by glycolysis
View answer and explanation

Correct answer:

  1. Lipid synthesis

Explanation: Smooth endoplasmic reticulum makes lipids and also participates in detoxification.

Question 6

Which feature is found in bacterial cells?

  1. A membrane-bound nucleus
  2. Mitochondria
  3. Ribosomes
  4. Chloroplasts
View answer and explanation

Correct answer:

  1. Ribosomes

Explanation: Bacteria have ribosomes for making proteins but lack membrane-bound organelles.

Question 7

Which plant-cell structure stores water and helps maintain turgor pressure?

  1. Central vacuole
  2. Nucleolus
  3. Ribosome
  4. Golgi apparatus
View answer and explanation

Correct answer:

  1. Central vacuole

Explanation: Water in the central vacuole helps press the cell contents against the cell wall.

Question 8

What is diffusion?

  1. Movement of water using ATP
  2. Movement of substances only through proteins
  3. Movement from lower to higher concentration using energy
  4. Net movement of particles from higher to lower concentration
View answer and explanation

Correct answer:

  1. Net movement of particles from higher to lower concentration

Explanation: Diffusion results from random particle motion and does not directly require cellular energy.

Question 9

What is osmosis?

  1. Movement of proteins into a nucleus
  2. Net movement of water across a selectively permeable membrane
  3. Breakdown of glucose into pyruvate
  4. Movement of chromosomes during mitosis
View answer and explanation

Correct answer:

  1. Net movement of water across a selectively permeable membrane

Explanation: Water moves toward the side with the higher effective solute concentration.

Question 10

Which process moves a substance against its concentration gradient using cellular energy?

  1. Simple diffusion
  2. Osmosis
  3. Active transport
  4. Passive transport
View answer and explanation

Correct answer:

  1. Active transport

Explanation: Active transport uses energy to move substances from lower to higher concentration.

Question 11

A white blood cell surrounds and engulfs a bacterium. Which process is occurring?

  1. Phagocytosis
  2. Exocytosis
  3. Osmosis
  4. Fermentation
View answer and explanation

Correct answer:

  1. Phagocytosis

Explanation: Phagocytosis is a form of endocytosis in which a cell engulfs large particles.

Question 12

Which process releases substances when a vesicle fuses with the cell membrane?

  1. Diffusion
  2. Meiosis
  3. Endocytosis
  4. Exocytosis
View answer and explanation

Correct answer:

  1. Exocytosis

Explanation: Exocytosis delivers vesicle contents to the outside of the cell.

Question 13

What is the main role of an enzyme?

  1. To store inherited information
  2. To speed up a chemical reaction
  3. To become permanently used up in a reaction
  4. To increase the energy needed to start a reaction
View answer and explanation

Correct answer:

  1. To speed up a chemical reaction

Explanation: Enzymes lower activation energy and are not consumed by the reactions they catalyze.

Question 14

What is the region of an enzyme where its substrate binds called?

  1. Gene locus
  2. Lipid tail
  3. Active site
  4. Centromere
View answer and explanation

Correct answer:

  1. Active site

Explanation: The active site binds the substrate and supports the reaction.

Question 15

Very high temperatures may stop an enzyme from working because they:

  1. Alter the enzyme’s shape
  2. Turn the enzyme into DNA
  3. Increase its chromosome number
  4. Remove every substrate molecule
View answer and explanation

Correct answer:

  1. Alter the enzyme’s shape

Explanation: Excessive heat can denature an enzyme, changing its active site.

Question 16

Which substances are the main reactants of aerobic cellular respiration?

  1. Carbon dioxide and water
  2. Oxygen and ATP
  3. Glucose and carbon dioxide
  4. Glucose and oxygen
View answer and explanation

Correct answer:

  1. Glucose and oxygen

Explanation: Aerobic respiration uses glucose and oxygen to release energy and produce carbon dioxide and water.

Question 17

Which gas is released during the Krebs cycle?

  1. Oxygen
  2. Carbon dioxide
  3. Nitrogen
  4. Hydrogen
View answer and explanation

Correct answer:

  1. Carbon dioxide

Explanation: Carbon atoms from fuel molecules are removed and released as carbon dioxide.

Question 18

Which molecule carries high-energy electrons to the electron transport chain?

  1. Cellulose
  2. Hemoglobin
  3. NADH
  4. Collagen
View answer and explanation

Correct answer:

  1. NADH

Explanation: NADH transfers electrons collected during earlier stages of respiration.

Question 19

What is the net ATP gain from glycolysis per glucose molecule?

  1. Two ATP
  2. Four ATP
  3. Six ATP
  4. Eight ATP
View answer and explanation

Correct answer:

  1. Two ATP

Explanation: Glycolysis produces four ATP but uses two, leaving a net gain of two.

Question 20

Which molecule is produced when human muscle cells carry out lactic acid fermentation?

  1. Ethanol
  2. Starch
  3. Oxygen
  4. Lactate
View answer and explanation

Correct answer:

  1. Lactate

Explanation: Pyruvate is converted into lactate, regenerating NAD⁺ so glycolysis can continue.

Question 21

A DNA nucleotide contains which three components?

  1. Amino acid, phosphate, and ribose
  2. Phosphate, deoxyribose sugar, and a nitrogenous base
  3. Glycerol, fatty acid, and a base
  4. Glucose, protein, and phosphate
View answer and explanation

Correct answer:

  1. Phosphate, deoxyribose sugar, and a nitrogenous base

Explanation: These three components form each building block of DNA.

Question 22

What is a gene?

  1. A complete organ system
  2. A type of cell membrane
  3. A DNA sequence containing instructions for a functional product
  4. A protein that digests chromosomes
View answer and explanation

Correct answer:

  1. A DNA sequence containing instructions for a functional product

Explanation: Genes contain information used to produce functional RNA or proteins.

Question 23

An organism with two identical alleles for a gene is described as:

  1. Homozygous
  2. Heterozygous
  3. Haploid
  4. Hybrid
View answer and explanation

Correct answer:

  1. Homozygous

Explanation: A homozygous genotype contains matching alleles, such as AA or aa.

Question 24

Under complete dominance, which allele determines the phenotype of a heterozygote?

  1. The recessive allele
  2. Neither allele
  3. Only the maternally inherited allele
  4. The dominant allele
View answer and explanation

Correct answer:

  1. The dominant allele

Explanation: A dominant allele determines the trait when paired with a recessive allele.

Question 25

In a cross between Aa and Aa, what is the probability of an aa offspring?

  1. 0%
  2. 25%
  3. 50%
  4. 100%
View answer and explanation

Correct answer:

  1. 25%

Explanation: The possible combinations are AA, Aa, Aa, and aa; one of four is aa.

Question 26

During which stage of mitosis do chromosomes line up at the cell’s equator?

  1. Prophase
  2. Telophase
  3. Metaphase
  4. Anaphase
View answer and explanation

Correct answer:

  1. Metaphase

Explanation: Chromosomes align in the middle of the cell before their chromatids separate.

Question 27

During which stage of mitosis do sister chromatids separate?

  1. Anaphase
  2. Prophase
  3. Metaphase
  4. Telophase
View answer and explanation

Correct answer:

  1. Anaphase

Explanation: Spindle fibers move the separated chromatids toward opposite poles.

Question 28

What joins to form a zygote during human fertilization?

  1. Two body cells
  2. Two sperm cells
  3. Two egg cells
  4. A sperm cell and an egg cell
View answer and explanation

Correct answer:

  1. A sperm cell and an egg cell

Explanation: Their haploid chromosome sets combine to form a diploid zygote.

Question 29

Which microscope part contains the lens closest to the specimen?

  1. Eyepiece
  2. Objective
  3. Arm
  4. Base
View answer and explanation

Correct answer:

  1. Objective

Explanation: The objective lens sits near the specimen and provides the initial magnified image.

Question 30

What does a microscope’s resolving power describe?

  1. Its ability to hold the slide still
  2. Its ability to change slide color
  3. Its ability to distinguish two close points as separate
  4. Its ability to increase specimen size alone
View answer and explanation

Correct answer:

  1. Its ability to distinguish two close points as separate

Explanation: Better resolution reveals finer detail, rather than simply producing a larger image.

Question 31

In the scientific name Homo sapiens, what does Homo identify?

  1. Genus
  2. Family
  3. Order
  4. Kingdom
View answer and explanation

Correct answer:

  1. Genus

Explanation: The first word of a binomial scientific name identifies the genus.

Question 32

Which taxonomic rank lies directly between class and family?

  1. Species
  2. Phylum
  3. Genus
  4. Order
View answer and explanation

Correct answer:

  1. Order

Explanation: The sequence is kingdom, phylum, class, order, family, genus, species.

Question 33

Why must viruses enter living cells to reproduce?

  1. They contain too many ribosomes
  2. They depend on the host’s cellular machinery
  3. They reproduce only by meiosis
  4. They must first become bacteria
View answer and explanation

Correct answer:

  1. They depend on the host’s cellular machinery

Explanation: Viruses lack the complete machinery needed to reproduce independently.

Question 34

Why do antibiotics used against bacteria generally fail to treat viral infections?

  1. Viruses have thicker bacterial cell walls
  2. Viruses are larger than human cells
  3. Viruses lack the bacterial targets of those antibiotics
  4. Viruses contain no genetic material
View answer and explanation

Correct answer:

  1. Viruses lack the bacterial targets of those antibiotics

Explanation: Many antibiotics target bacterial structures or processes that viruses do not possess.

Question 35

Which tissue contracts to produce body movement?

  1. Muscle tissue
  2. Epithelial tissue
  3. Nervous tissue
  4. Adipose tissue
View answer and explanation

Correct answer:

  1. Muscle tissue

Explanation: Muscle cells contain proteins that allow them to shorten and generate force.