Grade 10 general science – The Cell Quiz

1. Which of the following is a correct statement from the cell theory?

All organisms are made of only one cell
All cells have a nucleus
All cells arise from pre-existing cells
Cells can form spontaneously from non-living matter
Explanation:

One of the main points of cell theory is that cells come from pre-existing cells by cell division. Not all cells have a nucleus (bacteria do not), organisms can be multicellular, and spontaneous generation is incorrect.

2. Which organelle is the site of most ATP production in a eukaryotic cell?

Endoplasmic reticulum
Golgi apparatus
Mitochondrion
Ribosome
Explanation:

Mitochondria are the sites of aerobic respiration and produce most of the cell's ATP. Ribosomes make proteins, Golgi packages them, and ER is involved in synthesis and transport.

3. Which cell structure contains chlorophyll and carries out photosynthesis in plant cells?

Vacuole
Lysosome
Mitochondrion
Chloroplast
Explanation:

Chloroplasts contain chlorophyll and are the site of photosynthesis in plant cells. Mitochondria produce ATP, vacuoles store substances, and lysosomes break down waste.

4. Which structure gives plant cells a definite shape and strength?

Golgi apparatus
Cell membrane
Cell wall
Nucleus
Explanation:

The cell wall, made mainly of cellulose in plants, provides rigidity and protection. The cell membrane controls movement of substances, the nucleus stores genetic material, and the Golgi modifies proteins.

5. What is osmosis?

Movement of water from a region of higher water concentration to a region of lower water concentration through a partially permeable membrane
Random movement of particles in gases only
Movement of solutes from low to high concentration using energy
Active transport of large molecules by vesicles
Explanation:

Osmosis specifically refers to the passive movement of water across a partially permeable membrane from higher to lower water concentration (or lower to higher solute concentration). The other options describe different processes.

6. Which cell structure mainly controls entry and exit of substances into and out of the cell?

Cytoplasm
Cell membrane
Nucleus
Cell wall
Explanation:

The cell membrane is selectively permeable and regulates transport of materials. The nucleus holds genetic material, cytoplasm is the matrix of the cell, and the cell wall (in plants) provides support but does not control selective transport.

7. Which organelle is responsible for protein synthesis?

Lysosome
Chloroplast
Ribosome
Centriole
Explanation:

Ribosomes are the sites where amino acids are assembled into proteins according to mRNA instructions. Lysosomes digest material, chloroplasts photosynthesize, and centrioles assist in cell division in animals.

8. Which best describes mitosis?

Division of the nucleus producing two nuclei with the same number of chromosomes as the parent nucleus
Fusion of two gametes to form a zygote
Exchange of genetic material between bacteria
Production of four genetically different daughter cells
Explanation:

Mitosis is nuclear division that produces two genetically identical nuclei with the same chromosome number as the parent. Fusion of gametes is fertilisation, production of four different cells describes meiosis, and exchange in bacteria is conjugation.

9. Which organelle modifies, sorts and packages proteins for secretion?

Mitochondrion
Nucleolus
Ribosome
Golgi apparatus
Explanation:

The Golgi apparatus processes and packages proteins and lipids for transport or secretion. Mitochondria produce energy, ribosomes synthesise proteins, and the nucleolus makes ribosomal RNA.

10. Which structure is NOT present in a typical bacterial cell?

Nucleus
Cell membrane
Cell wall
Ribosome
Explanation:

Bacteria are prokaryotes and lack a true nucleus; their DNA is not enclosed in a nuclear membrane. They do have a cell membrane, ribosomes, and many have a cell wall.

11. Which human cell type carries oxygen around the body?

Red blood cell
Lymphocyte
Neutrophil
Platelet
Explanation:

Red blood cells (erythrocytes) contain haemoglobin that binds and transports oxygen. Neutrophils and lymphocytes are white blood cells involved in defence; platelets are involved in blood clotting.

12. Which of these is an example of a unicellular organism commonly studied in schools?

Amoeba
Frog
Sunflower
Human skin cell
Explanation:

Amoeba is a single-celled organism. Sunflowers, frogs and human tissues are multicellular organisms.

13. What is a major function of the large central vacuole in plant cells?

Movement of the cell
Storage of water and maintenance of cell turgor
Production of ATP
Site of protein synthesis
Explanation:

The plant vacuole stores water and solutes and maintains turgor pressure which keeps the plant rigid. Protein synthesis occurs at ribosomes, ATP at mitochondria, and cells move by other means.

14. Which microscope is commonly used in Kenyan school laboratories to observe cell shape and some internal structures?

X-ray microscope
Gamma-ray detector
Light microscope (compound)
Electron microscope
Explanation:

Compound light microscopes are common in school labs and allow observation of cell shape and some organelles. Electron microscopes give much higher detail but are not commonly available in schools.

15. Which cell structure stores the cell's hereditary information (DNA) in most eukaryotic cells?

Mitochondrion
Ribosome
Vacuole
Nucleus
Explanation:

The nucleus contains chromosomes made of DNA in eukaryotic cells. Mitochondria have their own small DNA but are not the main store; ribosomes make proteins and vacuoles store materials.

16. Which type of endoplasmic reticulum is associated with ribosomes and protein synthesis?

Rough endoplasmic reticulum
Smooth endoplasmic reticulum
Lipid endoplasmic reticulum
Golgi endoplasmic reticulum
Explanation:

Rough ER has ribosomes attached and is involved in synthesis and initial folding of proteins. Smooth ER lacks ribosomes and is involved in lipid synthesis and detoxification.

17. Which statement best describes active transport across a cell membrane?

Movement of molecules from high to low concentration without energy
Equal movement of molecules in both directions at all times
Movement of water only
Movement of molecules from low to high concentration using energy
Explanation:

Active transport requires energy (ATP) to move substances against their concentration gradient (from low to high). Movement from high to low without energy is passive transport; osmosis is water movement.

18. Which organelle contains digestive enzymes used to break down worn-out organelles and waste?

Nucleus
Chloroplast
Golgi apparatus
Lysosome
Explanation:

Lysosomes contain hydrolytic enzymes that digest cellular waste and damaged organelles. Chloroplasts photosynthesise, the nucleus stores DNA, and the Golgi packages materials.

19. Which two structures are present in plant cells but generally absent in animal cells?

Chloroplast and cell wall
Golgi apparatus and lysosome
Nucleus and cell membrane
Mitochondrion and ribosome
Explanation:

Plant cells have chloroplasts for photosynthesis and a rigid cell wall made of cellulose; animal cells do not. Mitochondria, ribosomes, nucleus, membrane, Golgi and lysosomes are found in both (though abundance may vary).

20. Why do very large cells tend to divide rather than just grow bigger?

Because a large cell has a low surface area to volume ratio, reducing efficient exchange of materials
Because cell walls prevent growth
Because large cells always have more mitochondria
Because DNA disappears when cells get large
Explanation:

As a cell grows its volume increases faster than its surface area, making diffusion of nutrients and wastes less efficient. To maintain efficient exchange, cells divide. The other options are incorrect.

21. Which structure is hair-like and used for movement and feeding in Paramecium?

Pseudopodia
Cilia
Cell wall
Flagellum
Explanation:

Paramecium moves and feeds using many short hair-like cilia. Pseudopodia are used by amoebae, flagella are longer whip-like structures used by some cells, and cell walls are rigid coverings in plants.

22. What are chromosomes mainly made of?

RNA only
Minerals and vitamins
Carbohydrates and lipids
DNA and proteins
Explanation:

Chromosomes consist of long DNA molecules packaged with proteins (histones) to form chromatin. Carbohydrates, lipids, RNA or minerals are not the main structural components.

23. Which process allows oxygen to move from air into leaf cells without the use of energy?

Active transport
Osmosis
Diffusion
Endocytosis
Explanation:

Oxygen moves by diffusion from an area of higher concentration (air spaces) to lower concentration (inside cells) without energy. Active transport requires energy, endocytosis is bulk uptake of materials, and osmosis is water movement.

24. Which feature is a key difference between prokaryotic and eukaryotic cells?

Eukaryotic cells have a nucleus and membrane-bound organelles; prokaryotic cells do not
Prokaryotic cells are larger than eukaryotic cells
Eukaryotic cells do not contain DNA; prokaryotic cells do
Prokaryotic cells always have chloroplasts; eukaryotic cells never do
Explanation:

Eukaryotes have a true nucleus and membrane-bound organelles. Prokaryotes lack these structures. The other statements are incorrect generalisations.

25. Which statement about multicellular organisms is correct?

Cells in multicellular organisms do not divide
Multicellular organisms are always microscopic
All cells in the organism have exactly the same shape and function
Cells become specialized to perform specific functions
Explanation:

In multicellular organisms cells differentiate and specialise (e.g., muscle, nerve, blood cells) to carry out particular tasks. Not all cells are identical, multicellular organisms can be large, and cells still divide for growth and repair.

26. Which statement is part of the cell theory taught in Kenyan basic science?

All organisms are made of one cell only
Cells can appear spontaneously from non-living matter
Cells do not contain genetic material
All cells arise from pre-existing cells
Explanation:

One key point of cell theory is that new cells are produced by division of existing cells; the other options contradict established biology.

27. What is the main function of the nucleus in a typical plant or animal cell?

To store and protect genetic information
To capture light energy and make food
To break down foreign materials with digestive enzymes
To synthesise large amounts of ATP directly
Explanation:

The nucleus contains DNA which stores genes and controls cell activities; ATP production is mainly mitochondrial, digestion is by lysosomes, and light capture is by chloroplasts.

28. Which organelle is primarily responsible for producing most of the cell's energy (ATP)?

Ribosome
Cell wall
Golgi apparatus
Mitochondrion
Explanation:

Mitochondria carry out cellular respiration to produce ATP, whereas Golgi modifies proteins, ribosomes make proteins, and cell wall provides support.

29. Where does photosynthesis take place in green plant cells such as a maize leaf?

Lysosome
Mitochondrion
Nucleus
Chloroplast
Explanation:

Chloroplasts contain chlorophyll and are the site of photosynthesis; mitochondria carry out respiration and lysosomes digest waste.

30. Which structure provides rigid support and protection to plant cells but is absent from animal cells?

Cell wall
Cell membrane
Rough endoplasmic reticulum
Centrioles
Explanation:

Plant cells have a rigid cell wall made of cellulose for support; cell membrane is in both cell types and centrioles are typically in animal cells.

31. What is the main role of the cell membrane?

To control movement of substances into and out of the cell
To store food reserves like starch
To produce ribosomes
To generate visible light for photosynthesis
Explanation:

The cell membrane is selectively permeable and regulates transport; storage of starch is in plastids or vacuoles, and ribosomes are made in the nucleolus.

32. Which organelle is the site of protein synthesis?

Golgi apparatus
Vacuole
Ribosome
Smooth endoplasmic reticulum
Explanation:

Ribosomes translate mRNA to make proteins; smooth ER is involved in lipid synthesis, Golgi modifies and packages proteins, and vacuoles store substances.

33. Which of these distinguishes prokaryotic cells from eukaryotic cells?

Prokaryotes are always multicellular
Prokaryotes have chloroplasts in all cells
Prokaryotes contain membrane-bound mitochondria
Prokaryotes lack a true membrane-bound nucleus
Explanation:

Prokaryotes (like bacteria) have no membrane-bound nucleus; they do not have mitochondria or chloroplasts and are usually unicellular.

34. Which structure modifies, sorts and packages proteins for secretion or use in the cell?

Golgi apparatus
Ribosome
Cell wall
Mitochondrion
Explanation:

The Golgi apparatus processes and packages proteins and lipids; ribosomes make proteins and mitochondria produce energy.

35. What is the function of a large central vacuole in plant cells?

To digest worn-out cell parts using enzymes
To produce ATP for cellular activities
To synthesise proteins needed for cell growth
To store water, nutrients and help maintain turgor pressure
Explanation:

Plant vacuoles store water and dissolved substances and maintain turgor; protein synthesis is by ribosomes and digestion by lysosomes.

36. Which process describes the movement of water across a partially permeable membrane from a region of high water concentration to low water concentration?

Osmosis
Endocytosis
Diffusion of solute
Active transport
Explanation:

Osmosis is specifically the movement of water across a membrane; diffusion is for solutes, and active transport requires energy.

37. Diffusion is best described as:

Movement of particles against a concentration gradient using energy
Bulk flow of water through membrane channels
Net movement of particles from high concentration to low concentration
A process unique to living cells only
Explanation:

Diffusion is passive movement down a concentration gradient and does not require energy; active transport moves against a gradient.

38. Which statement about active transport is true?

It requires cellular energy to move substances against a concentration gradient
It moves particles only from high to low concentration without energy
It only occurs in plant roots
It is the same as simple diffusion
Explanation:

Active transport uses ATP to move ions or molecules against their concentration gradient and can occur in many cell types including root cells.

39. In animal cells which organelle contains enzymes that digest worn-out organelles and foreign materials?

Cellulose cell wall
Ribosome
Chloroplast
Lysosome
Explanation:

Lysosomes contain hydrolytic enzymes for intracellular digestion; chloroplasts perform photosynthesis and ribosomes make proteins.

40. Which structure is present in plant cells but not in most animal cells and helps in photosynthesis and storage of starch?

Centrosome
Flagellum
Plastid
Cilia
Explanation:

Plastids (including chloroplasts and amyloplasts) are plant organelles for photosynthesis and starch storage; flagella, centrosomes and cilia are typical of some animal cells or protists.

41. What is the role of the rough endoplasmic reticulum (RER)?

To synthesise and transport proteins with attached ribosomes on its surface
To generate ATP through oxidative phosphorylation
To package proteins for export outside the cell as its only function
To produce lipids and detoxify harmful substances exclusively
Explanation:

RER has ribosomes and is involved in protein synthesis and transport; lipid synthesis and detoxification are functions of smooth ER.

42. Which of the following best describes chromosomes?

Structures that pump water into the cell
Long molecules of DNA carrying genes
Small organelles that make proteins
Membrane-bound sacs for storing food
Explanation:

Chromosomes are made of DNA and contain genes which determine characteristics; the other options describe organelles or functions that chromosomes do not perform.

43. A microscope has an eyepiece lens of 10x and an objective lens of 40x. What is the total magnification?

4000x
50x
4x
400x
Explanation:

Total magnification is the product of eyepiece and objective magnifications: 10 x 40 = 400.

44. Which cell process results in two daughter cells genetically identical to the parent cell and is important for growth?

Mitosis followed by cytokinesis
Binary fission in animal tissue only
Transpiration at the leaf surface
Meiosis producing four gametes
Explanation:

Mitosis divides the nucleus and cytokinesis divides the cytoplasm producing two identical daughter cells; meiosis produces genetically different gametes.

45. Which molecule makes up the main structural component of the cell membrane?

Double-stranded RNA sheets
Cellulose microfibrils
Phospholipids arranged in a bilayer
Peptidoglycan crystals
Explanation:

Cell membranes consist mainly of a phospholipid bilayer with proteins; cellulose is in cell walls and peptidoglycan is in bacterial cell walls.

46. Which of the following best explains cell specialization (differentiation)?

All cells always remain identical in structure and function
Cells stop using their DNA during specialization
Cells develop different structures and functions to perform specific tasks
Cells only change when exposed to chemicals in the laboratory
Explanation:

Differentiation produces specialized cells (like root hair cells or muscle cells) with specific structures for their roles while still using DNA.

47. What is found in bacterial cells but not in animal cells?

Plasmid DNA
Chloroplast
Membrane-bound nucleus
Mitochondria
Explanation:

Many bacteria have plasmids (small circular DNA) and lack membrane-bound organelles found in eukaryotes such as nuclei, mitochondria, or chloroplasts.

48. Which of these best describes the cytoplasm of a cell?

A rigid outer covering that protects the cell from the environment
A solid crystal structure that gives the cell its colour
The site where chromosomes are permanently stored outside the nucleus
A jelly-like substance where organelles are suspended and metabolic reactions occur
Explanation:

Cytoplasm contains organelles and is the site of many chemical reactions; the rigid covering is the cell wall and chromosomes are stored in the nucleus in eukaryotes.

49. Which process moves glucose into a cell when its concentration outside is lower than inside and requires energy?

Active transport
Simple diffusion
Facilitated diffusion without energy
Osmosis
Explanation:

Active transport uses ATP to move substances like glucose against a concentration gradient; diffusion and facilitated diffusion are passive and move down gradients.

50. Which organelle is responsible for packaging materials into vesicles for transport within or out of the cell in plant or animal cells found in Kenyan schools?

Centriole
Nucleolus
Golgi apparatus
Peroxisome
Explanation:

The Golgi apparatus modifies and packages proteins and lipids into vesicles for transport; the nucleolus makes ribosomal RNA.