Biology some mock questions

1. Which structure is found in plant cells but not in animal cells?
A. Mitochondrion
B. Ribosome
C. Cell wall
D. Nucleus
Answer: C. Cell wall

2. Which best explains why muscle cells and nerve cells look different and perform different functions?
A. They contain different DNA
B. They are in different organs
C. They use different parts of the same DNA
D. They have different numbers of chromosomes
Answer: C. They use different parts of the same DNA

3. During photosynthesis, plants take in carbon dioxide and release —
A. Nitrogen
B. Glucose
C. Oxygen
D. ATP
Answer: C. Oxygen

4. What is the main function of the mitochondria?
A. To store genetic material
B. To produce proteins
C. To carry out photosynthesis
D. To convert energy in food into usable ATP
Answer: D. To convert energy in food into usable ATP

5. What is the correct order of organization in living organisms from simplest to most complex?
A. Organism → Organ system → Tissue → Cell
B. Cell → Tissue → Organ → Organ system
C. Tissue → Cell → Organ → Organism
D. Organ system → Organ → Cell → Tissue
Answer: B. Cell → Tissue → Organ → Organ system

6. In which situation would natural selection most likely occur?
A. All individuals in a species are genetically identical
B. A population lives in an unchanging environment
C. Some individuals are better adapted to the environment
D. The environment has unlimited resources
Answer: C. Some individuals are better adapted to the environment

7. What is the result of mitosis?
A. Four genetically unique cells
B. Two genetically identical cells
C. Two cells with half the chromosomes
D. One cell with double the chromosomes
Answer: B. Two genetically identical cells

8. Which molecule carries the genetic code from the nucleus to the ribosome?
A. DNA
B. tRNA
C. rRNA
D. mRNA
Answer: D. mRNA

9. A mutation in DNA may cause a change in —
A. Temperature
B. Cell size
C. Protein structure
D. The amount of cytoplasm
Answer: C. Protein structure

10. In a Punnett square, what does each box represent?
A. One gene
B. One trait
C. A possible genotype of offspring
D. A chromosome
Answer: C. A possible genotype of offspring

11. Which of the following processes requires energy input?
A. Osmosis
B. Diffusion
C. Active transport
D. Facilitated diffusion
Answer: C. Active transport

12. Which of the following describes biodiversity?
A. The amount of rainfall in a tropical forest
B. The number of species in an ecosystem
C. The temperature variation over time
D. The types of soil in a given region
Answer: B. The number of species in an ecosystem

13. Which best describes the role of decomposers in an ecosystem?
A. Capture energy from the sun
B. Consume living animals
C. Break down dead organisms
D. Provide shelter for herbivores
Answer: C. Break down dead organisms

14. What would most likely happen if all the producers were removed from a food web?
A. Herbivores would increase
B. Carnivores would become producers
C. All other organisms would be affected
D. Decomposers would become consumers
Answer: C. All other organisms would be affected

15. What is the purpose of meiosis?
A. To create identical copies of a cell
B. To repair damaged cells
C. To reduce the chromosome number for sexual reproduction
D. To double the chromosome number in body cells
Answer: C. To reduce the chromosome number for sexual reproduction