Biology Concepts Practice Questions
K-12 (Philippines) · K-12 Science · 137 free MCQs with instant results and detailed explanations.
137
Total
34
Easy
74
Medium
29
Hard
Start Practicing Biology Concepts
Take a timed quiz or customize your practice session
Sample Questions from Biology Concepts
Here are 10 sample questions. Start a quiz to get randomized questions with scoring.
Q1
Easy
What is the primary function of the cell membrane?
A.
To control what enters and exits the cell
B.
To produce energy in the form of ATP
C.
To store genetic information
D.
To synthesize proteins
Show Answer & Explanation
Correct Answer: A
The cell membrane regulates the movement of substances in and out of the cell, maintaining homeostasis.
Q2
Easy
Which of the following organisms performs photosynthesis?
A.
Fungi
B.
Plants
C.
Animals
D.
Bacteria
Show Answer & Explanation
Correct Answer: B
Plants are capable of photosynthesis, a process that converts light energy into chemical energy stored in glucose.
Q3
Easy
What is the role of mitochondria in a cell?
A.
To package and distribute proteins
B.
To synthesize glucose
C.
To produce energy through cellular respiration
D.
To store waste products
Show Answer & Explanation
Correct Answer: C
Mitochondria are known as the powerhouse of the cell because they generate ATP through the process of cellular respiration.
Q4
Medium
What process do plants primarily use to convert sunlight into chemical energy?
A.
Respiration
B.
Fermentation
C.
Photosynthesis
D.
Transpiration
Show Answer & Explanation
Correct Answer: C
Photosynthesis is the process by which plants use sunlight to convert carbon dioxide and water into glucose and oxygen. This process is essential for the production of chemical energy in plants.
Q5
Medium
Which of the following is a function of the cell membrane?
A.
Storage of genetic information
B.
Regulation of substance entry and exit
C.
Protein synthesis
D.
Photosynthesis
Show Answer & Explanation
Correct Answer: B
The cell membrane regulates what enters and exits the cell, maintaining homeostasis. It is selectively permeable, allowing certain substances to pass while blocking others.
Q6
Medium
Which of the following best explains how genetic traits are passed from parents to offspring?
A.
Through environmental influences
B.
Via genetic mutations only
C.
Through genes located on chromosomes
D.
By random chance
Show Answer & Explanation
Correct Answer: C
Genetic traits are transmitted from parents to offspring through genes, which are located on chromosomes. This genetic material carries the information needed for trait inheritance.
Q7
Medium
Which organelle is responsible for energy production in eukaryotic cells?
A.
Nucleus
B.
Ribosome
C.
Mitochondrion
D.
Endoplasmic reticulum
Show Answer & Explanation
Correct Answer: C
Mitochondria are known as the powerhouse of the cell because they generate ATP through cellular respiration, providing energy for various cellular activities.
Q8
Hard
A biologist conducts an experiment on the effect of light intensity on the rate of photosynthesis in plants. If he finds that increasing light intensity up to a certain point increases the rate of photosynthesis but then levels off, what is this phenomenon called?
A.
Light Saturation
B.
Photosynthetic Efficiency
C.
Rate Limiting Factor
D.
Chemical Equilibrium
Show Answer & Explanation
Correct Answer: A
The phenomenon where the rate of photosynthesis increases with light intensity but eventually levels off due to saturation is called Light Saturation. This indicates that the maximum rate of photosynthesis has been reached, making option A the correct answer.
Q9
Hard
Which of the following processes describes how plants convert sunlight into chemical energy?
A.
Respiration
B.
Photosynthesis
C.
Fermentation
D.
Transpiration
Show Answer & Explanation
Correct Answer: B
Photosynthesis is the process by which plants, algae, and some bacteria convert light energy into chemical energy in the form of glucose, using sunlight, carbon dioxide, and water. This process is essential for plant growth and energy production.
Q10
Hard
A scientist conducts an experiment to observe the effect of varying temperatures on the rate of enzyme activity. If the optimal temperature for the enzyme is 37°C, which of the following statements is most likely true about the enzyme activity at 50°C?
A.
Enzyme activity will increase sharply.
B.
Enzyme activity will decrease due to denaturation.
C.
Enzyme activity will remain unchanged.
D.
Enzyme activity will double.
Show Answer & Explanation
Correct Answer: B
At temperatures significantly higher than the optimal range (37°C for many enzymes), enzymes can denature, meaning they lose their three-dimensional structure and function, leading to a decrease in activity. Thus, enzyme activity at 50°C is likely to decrease.
Showing 10 of 137 questions. Start a quiz to practice all questions with scoring and timer.
Practice All 137 Questions →Other K-12 (Philippines) Subjects
Biology Concepts — K-12 (Philippines) K-12 Science Practice Questions Online
This page contains 137 practice MCQs for the chapter Biology Concepts in K-12 (Philippines) K-12 Science. The questions are organized by difficulty — 34 easy, 74 medium, 29 hard — so you can choose the right level for your preparation.
Every question includes a detailed explanation to help you understand the concept, not just memorize answers. Take a timed quiz to simulate exam conditions, or practice at your own pace with no time limit.