Cell Theory
1. Which of the following correctly shows the hierarchy from smallest to largest biological component?
A) Species → Organs → Cells → Ecosystem
B) Cells → Tissues → Organs → Organisms
C) Organs → Cells → Species → Tissues
D) Ecosystem → Organ → Tissue → Cell
B) Cells → Tissues → Organs → Organisms
4. What is the main function of the cell membrane?
A) Produce energy for the cell
B) Control what enters and leaves the cell
C) Store genetic information
D) Break down waste materials
B) Control what enters and leaves the cell
11. When the human body gets too hot, a feedback mechanism causes:
A) Shivering to generate heat
B) Sweating to cool the body
C) Increased heart rate to warm the blood
D) Stopping all muscle movement
B) Sweating to cool the body
3. Which structure is found in plant cells but not in animal cells?
A) Mitochondria
B) Cell wall
C) Ribosomes
D) Lysosomes
B) Cell wall
13. What is the main purpose of DNA replication?
A) To produce energy for the cell
B) To create a copy of genetic information before cell division
C) To build proteins
D) To remove damaged DNA
B) To create a copy of genetic information before cell division
2. Which of the following is a characteristic of eukaryotic cells but NOT prokaryotic cells?
A) Lack of a nucleus
B) Presence of membrane-bound organelles
C) Smaller size
D) Simple cell structure
B) Presence of membrane-bound organelles
7. Homeostasis is important because it helps organisms:
A) Grow and reproduce quickly
B) Maintain stable internal conditions despite external changes
C) Increase their body temperature constantly
D) Change their genetic makeup
B) Maintain stable internal conditions despite external changes
9. If you increase the concentration of salt outside a cell, what homeostatic process might the cell use to maintain balance?
A) Photosynthesis
B) Osmosis
C) Protein synthesis
D) Respiration
B) Osmosis
5. Proteins in a cell primarily determine its structure and function because they:
A) Store genetic information
B) Provide energy for cellular activities
C) Act as enzymes and structural components
D) Transport oxygen throughout the body
C) Act as enzymes and structural components
14. Which structure helps separate chromosomes during cell division?
A) Ribosome
B) Cell membrane
C) Spindle fibers
D) Mitochondria
C) Spindle fibers
6. Which example best shows interaction between two biological systems?
A) Heart pumping blood through the circulatory system
B) Roots absorbing water from the soil in plants
C) Organelles working together to produce energy inside a cell
D) Birds flying in a flock
A) Heart pumping blood through the circulatory system
8. Which of the following is an example of a homeostatic system in the human body?
A) Digesting food in the stomach
B) Regulating body temperature through sweating
C) Breathing in oxygen
D) Moving muscles to walk
B) Regulating body temperature through sweating
10. A negative feedback mechanism works by:
A) Amplifying a change until the organism adapts
B) Reversing a change to return to a set point
C) Ignoring environmental changes
D) Causing permanent changes to the organism
B) Reversing a change to return to a set point
21. Which cell structure is primarily responsible for producing energy needed for life processes?
A) Nucleus
B) Mitochondria
C) Ribosomes
D) Golgi apparatus
B) Mitochondria
15. During which phase of the cell cycle does DNA replication occur?
A) G1 phase
B) S phase
C) G2 phase
D) M phase
B) S phase
19. How does cell differentiation help an organism grow and develop?
A) By allowing cells to perform the same function throughout the body
B) By enabling cells to become specialized for different functions
C) By stopping cell division once the organism reaches maturity
D) By causing cells to lose their genetic material
B) By enabling cells to become specialized for different functions
23. What role does the cell membrane play in maintaining internal conditions?
A) It provides structural support to the cell
B) It controls the movement of substances in and out of the cell to keep conditions stable
C) It produces proteins for the cell
D) It stores genetic information
B) It controls the movement of substances in and out of the cell to keep conditions stable
12. How do feedback mechanisms help cells maintain water balance?
A) By producing more water within the cell
B) By actively transporting water molecules in or out to balance concentration
C) By stopping all water movement
D) By changing the DNA sequence
B) By actively transporting water molecules in or out to balance concentration
25. When blood sugar levels rise after eating, which process helps maintain internal balance?
A) Positive feedback increases sugar production
B) Negative feedback signals the release of insulin to lower blood sugar
C) Cells stop absorbing glucose
D) The pancreas stops working
B) Negative feedback signals the release of insulin to lower blood sugar
16. Mitosis is important because it:
A) Creates genetically unique cells for reproduction
B) Passes identical genetic information to new cells for growth and repair
C) Removes old cells from the body
D) Changes the DNA sequence
B) Passes identical genetic information to new cells for growth and repair
22. How does the structure of a nerve cell help it perform its function?
A) Its flat shape allows it to absorb sunlight
B) Its long extensions (axons) help transmit electrical signals over distances
C) Its rigid cell wall protects it from injury
D) Its many mitochondria allow it to store food
B) Its long extensions (axons) help transmit electrical signals over distances
24. Which system in the human body helps regulate internal temperature to maintain homeostasis?
A) Digestive system
B) Circulatory system
C) Nervous system
D) Respiratory system
C) Nervous system
19. Which type of cell differentiation is essential for the development of different tissues in an organism?
A) Nerve cells transmitting signals
B) Muscle cells contracting to enable movement
C) Bone cells providing structural support
D) All of the above
D) All of the above
18. Cellular differentiation during growth means that:
A) All cells remain identical to each other
B) Cells become specialized to perform different functions
C) Cells stop dividing completely
D) Cells lose their DNA
B) Cells become specialized to perform different functions
17. Which situation best illustrates a problem caused by loss of control of the cell cycle?
A) Muscle growth
B) Development of cancerous tumors
C) Wound healing
D) Immune response
B) Development of cancerous tumors