Question 1 of 10
A scientist measures the growth of bacteria at different temperatures. The temperature is the:
Acontrol variable
Bindependent variable
Cconstant
Ddependent 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 2 of 10
Which organelle is labeled X in the cell diagram below?
ANucleus
BEndoplasmic reticulum
CGolgi apparatus
DMitochondria
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 3 of 10
The DNA double helix is shown. Which base pairs are correctly bonded?
AA pairs with T, and G pairs with C
BAll bases pair with each other freely
CA pairs with G, and T 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 4 of 10
Which structure is found in plant cells but NOT in animal cells?
ACell wall
BRibosomes
CMitochondria
DCell membrane
Explanation
📌 Plant cells have: cell wall, chloroplasts, large central vacuole.
Animal cells do NOT have these.
Animal cells do NOT have these.
Question 5 of 10
Which organelle is responsible for producing energy (ATP) in the cell?
ARibosome
BGolgi apparatus
CNucleus
DMitochondria
Explanation
📌 Mitochondria = 'powerhouse of the cell'
They convert glucose + oxygen → ATP through cellular respiration.
They convert glucose + oxygen → ATP through cellular respiration.
Question 6 of 10
What is the function of the cell membrane?
ABuilds and assembles all of the cell's various proteins
BStores all of the cell's genetic information and DNA
CProduces the energy that the entire cell needs to survive
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
Which graph correctly shows exponential growth?
ANeither
BBoth
CA
DB
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 8 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
BIf plants receive more sunlight, then they will grow taller
CPlants need water
DPhotosynthesis is a very important process for living things on Earth
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 9 of 10
Which tool would be MOST appropriate for measuring the volume of a liquid?
AThermometer
BRuler
CBalance
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 10 of 10
In a controlled experiment, what is the independent variable?
AThe variable that stays constant
BThe control group
CThe variable that is deliberately changed
DThe variable that is measured
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.