Question 1 of 10
The DNA double helix is shown. Which base pairs are correctly bonded?
AAll bases pair with each other freely
BA pairs with G, and T pairs with C
CA pairs with T, and G pairs with C
DA pairs with C, and T pairs with G
Explanation
In DNA, complementary base pairing is strict: Adenine (A) – Thymine (T) via 2 hydrogen bonds; Guanine (G) – Cytosine (C) via 3 hydrogen bonds.
Question 2 of 10
Which of the following is the BEST example of a hypothesis?
AEvery single plant that exists is green in color without any exception
BPhotosynthesis is a very important process for living things on Earth
CIf plants receive more sunlight, then they will grow taller
DPlants need water
Explanation
📌 A hypothesis is a testable, specific prediction.
The if-then statement about sunlight and plant height is testable and specific. A simple need statement, a broad value judgment, or a sweeping generalization cannot be tested the same way.
The if-then statement about sunlight and plant height is testable and specific. A simple need statement, a broad value judgment, or a sweeping generalization cannot be tested the same way.
Question 3 of 10
Which tool would be MOST appropriate for measuring the volume of a liquid?
ABalance
BRuler
CThermometer
DGraduated cylinder
Explanation
📌 A graduated cylinder is specifically designed for precise liquid volume measurement.
Beakers and flasks are for mixing, not precise measurement.
Beakers and flasks are for mixing, not precise measurement.
Question 4 of 10
Which graph correctly shows exponential growth?
AB
BNeither
CBoth
DA
Explanation
📌 Exponential growth = J-shaped curve (slow start, rapid increase)
Linear growth = straight line (constant rate)
Graph A shows exponential growth.
Linear growth = straight line (constant rate)
Graph A shows exponential growth.
Question 5 of 10
Which organelle is labeled X in the cell diagram below?
AGolgi apparatus
BNucleus
CMitochondria
DEndoplasmic reticulum
Explanation
📌 Organelle X has the bean-shaped structure with inner folds (cristae) → Mitochondria
Mitochondria = powerhouse of the cell = produces ATP through cellular respiration
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP
Mitochondria = powerhouse of the cell = produces ATP through cellular respiration
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP
Question 6 of 10
What is the function of the cell membrane?
AProduces the energy that the entire cell needs to survive
BStores all of the cell's genetic information and DNA
CBuilds and assembles all of the cell's various proteins
DControls what enters and exits the cell
Explanation
📌 The cell membrane is selectively permeable — it controls what enters and exits the cell.
It is made of a phospholipid bilayer. Storing genetic information is the nucleus's job, producing energy is the mitochondrion's, and building proteins is done by ribosomes.
It is made of a phospholipid bilayer. Storing genetic information is the nucleus's job, producing energy is the mitochondrion's, and building proteins is done by ribosomes.
Question 7 of 10
A scientist measures the growth of bacteria at different temperatures. The temperature is the:
Adependent variable
Bcontrol variable
Cconstant
Dindependent variable
Explanation
📌 Temperature is what the scientist controls/changes → independent variable.
Bacteria growth is what is measured → dependent variable.
Bacteria growth is what is measured → dependent variable.
Question 8 of 10
Which organelle is responsible for producing energy (ATP) in the cell?
AMitochondria
BGolgi apparatus
CRibosome
DNucleus
Explanation
📌 Mitochondria = 'powerhouse of the cell'
They convert glucose + oxygen → ATP through cellular respiration.
They convert glucose + oxygen → ATP through cellular respiration.
Question 9 of 10
In a controlled experiment, what is the independent variable?
AThe variable that is deliberately changed
BThe variable that is measured
CThe control group
DThe variable that stays constant
Explanation
📌 The independent variable is what the scientist deliberately changes/manipulates.
The dependent variable is what is measured as a result.
The dependent variable is what is measured as a result.
Question 10 of 10
Which structure is found in plant cells but NOT in animal cells?
AMitochondria
BCell membrane
CCell wall
DRibosomes
Explanation
📌 Plant cells have: cell wall, chloroplasts, large central vacuole.
Animal cells do NOT have these.
Animal cells do NOT have these.