Cells and Microscopy Practice Quiz (19 questions)

1. A microscope image of a specimen appears blurred. What should the observer do to make it clearer?

A. Reposition the slide

B. Turn the focus knob

C. Move the stage

D. Look through the objective lens

Answer: (B)

Explanation

Turning the focus knob brings a blurred specimen into clearer focus. Moving the stage or slide changes position, while the objective lens is not where the scientist looks through.

2. A student is setting up a microscope to magnify a leaf sample. Where should the student place the sample?

A. On the focus knob

B. Against the objective lens

C. On the stage

D. At the eyepiece

Answer: (C)

Explanation

The specimen is placed on the microscope stage for magnification. The eyepiece is where the observer looks, the objective lens magnifies, and the focus knob is turned to sharpen the image.

3. What did Robert Hooke use to examine a thin slice of cork?

A. A magnifying glass

B. A camera

C. A telescope

D. A microscope

Answer: (D)

Explanation

Robert Hooke used a microscope to look at a thin slice of cork. A magnifying glass is a related viewing aid, while a telescope and camera are not the instrument identified for his cork examination.

4. What name did Robert Hooke give to the tiny room-like structures he observed in cork?

A. Cells

B. Tissues

C. Organisms

D. Organelles

Answer: (A)

Explanation

Hooke called the tiny room-like structures he saw in cork cells. Tissues are groupings of cells, organelles are cell components, and organisms are living things.

5. Which statement describes the cellular makeup of organisms?

A. All organisms are made up of cells

B. Animal organisms are made up of cells

C. All organisms are made up of tissues

D. Plant organisms are made up of cells

Answer: (A)

Explanation

All organisms are made up of cells, including plants and animals. Tissues are composed of cells, and restricting the statement to either plants or animals leaves out other organisms.

6. A collection contains a red blood cell, a root hair cell, a sperm cell, and a leaf cell. Which classification correctly groups them?

A. Animal: red blood and sperm; plant: root hair and leaf

B. Animal: sperm and leaf; plant: red blood and root hair

C. Animal: root hair and leaf; plant: red blood and sperm

D. Animal: red blood and root hair; plant: sperm and leaf

Answer: (A)

Explanation

Red blood cells and sperm cells are animal cells, whereas root hair cells and leaf cells are plant cells. The other groupings incorrectly assign at least one cell type to the opposite category.

7. A plant cell uses sunlight to make food, while another process releases usable energy from that food. Which process releases the energy?

A. Binary fission

B. Diffusion

C. Respiration

D. Photosynthesis

Answer: (C)

Explanation

Respiration releases energy from food, whereas photosynthesis makes food using sunlight. Photosynthesis is the food-making process, diffusion is movement from higher to lower concentration, and binary fission is amoeba reproduction.

8. A dissolved substance is more concentrated outside a cell than inside it. If it moves by diffusion, which direction will it move?

A. From inside to outside, from higher to lower concentration

B. From outside to inside, from lower to higher concentration

C. From inside to outside, from lower to higher concentration

D. From outside to inside, from higher to lower concentration

Answer: (D)

Explanation

Diffusion moves substances from a region of higher concentration to a region of lower concentration, so the substance moves into the cell in this situation. The alternatives reverse either the direction of movement or the concentration gradient.

9. A student arranges a mitochondrion, a human sperm cell, a human egg cell, and a human embryo from smallest to largest. Which sequence is correct?

A. Mitochondrion, sperm cell, embryo, egg cell

B. Mitochondrion, sperm cell, egg cell, embryo

C. Mitochondrion, egg cell, sperm cell, embryo

D. Sperm cell, mitochondrion, egg cell, embryo

Answer: (B)

Explanation

The size order from smallest to largest is mitochondrion, human sperm cell, human egg cell, and human embryo. The other sequences each misplace a particular pair in that order.

10. A microscope has an eyepiece magnification of 12 and an objective magnification of 5. What is its total magnification?

A. 17 times

B. 2.4 times

C. 60 times

D. 144 times

Answer: (C)

Explanation

Total magnification is the eyepiece magnification multiplied by the objective magnification: $12 \times 5 = 60$. Adding gives 17, using the eyepiece twice gives 144, and dividing the values gives 2.4.

11. Which animal cell structure stores the genetic material?

A. Mitochondrion

B. Cell membrane

C. Cytoplasm

D. Nucleus

Answer: (D)

Explanation

The nucleus stores the genetic material. The mitochondrion is where respiration takes place, the cytoplasm is where chemical reactions take place, and the cell membrane forms a barrier that lets substances move across it.

12. In an animal cell, which structure should a researcher examine to locate where respiration takes place?

A. Nucleus

B. Cytoplasm

C. Mitochondrion

D. Cell membrane

Answer: (C)

Explanation

Respiration takes place in the mitochondrion. The nucleus stores genetic material, the cytoplasm is where chemical reactions take place, and the cell membrane forms the boundary that permits substances to move across it.

13. A chemical reaction is observed in the jelly-like interior of an animal cell. Which structure contains this reaction?

A. Cytoplasm

B. Cell membrane

C. Mitochondrion

D. Nucleus

Answer: (A)

Explanation

The cytoplasm is the jelly-like substance where chemical reactions take place. The nucleus stores genetic material, the mitochondrion is where respiration occurs, and the cell membrane is the surrounding barrier.

14. A cell structure forms the outer barrier and allows substances to move across it. Which structure is being described?

A. Nucleus

B. Cell membrane

C. Mitochondrion

D. Cytoplasm

Answer: (B)

Explanation

The cell membrane forms the barrier around the cell and lets substances move across it. The nucleus stores genetic material, the mitochondrion is where respiration takes place, and the cytoplasm is the jelly-like interior where chemical reactions occur.

15. Theo wants to test whether the size of a red gel cube affects how quickly its colour spreads through clear gel. Which pair of measurements would let him investigate this relationship?

A. Cube size as the independent variable and diffusion rate as the dependent variable, each with suitable units and a sensible range

B. Cube size as the independent variable and colour intensity as the dependent variable, each with suitable units and a sensible range

C. Elapsed time as the independent variable and Petri-dish diameter as the dependent variable, each with suitable units and a sensible range

D. Diffusion rate as the independent variable and cube size as the dependent variable, each with suitable units and a sensible range

Answer: (A)

Explanation

To test whether cube size affects diffusion speed, cube size is the independent variable and diffusion rate is the dependent variable; both should be measured with suitable units over a sensible range. Reversing the variables confuses cause and outcome, using dish diameter substitutes an irrelevant measurement, and colour intensity is not the stated diffusion-rate outcome.

16. In Theo's described diffusion setup, what is placed at the centre of the clear gel in the Petri dish?

A. A 1 cm³ cube of red gel

B. A 1 cm³ cube of clear gel

C. A 10 cm-diameter red gel disc

D. A 10 cm³ cube of red gel

Answer: (A)

Explanation

Theo places a 1 cm³ cube of red gel at the centre of the clear gel. The 10 cm measurement describes the Petri dish's diameter, not the cube's volume; the cube is red, not clear, and it is not a disc.

17. A sperm cell must travel toward an egg and provide the energy needed for this movement. Which set of adaptations best supports these functions?

A. A tail for energy release, a streamlined head, and many mitochondria for movement

B. A tail for nutrient absorption, a streamlined head, and many mitochondria for energy release

C. A tail for movement, a streamlined head for energy release, and many mitochondria

D. A tail for movement, a streamlined head, and many mitochondria for energy release

Answer: (D)

Explanation

The sperm cell's tail helps it move, its streamlined head suits its shape for travel, and its many mitochondria provide energy. Nutrient absorption is not the tail's stated role, the head is not the energy source, and mitochondria do not propel the cell directly.

18. Which description identifies the adaptations highlighted in a sperm cell as helping it perform its job?

A. A tail, a streamlined head, and a large vacuole

B. A tail, many mitochondria, and a thick cell wall

C. A tail, a large food store, and many mitochondria

D. A tail, a streamlined head, and many mitochondria

Answer: (D)

Explanation

The highlighted sperm adaptations are its tail, streamlined head, and many mitochondria, which suit the cell to its job. A large food store or vacuole is not part of this specified set, and a sperm cell does not have a cell wall.

19. A microscope slide contains an amoeba, a single-celled organism. Which broad group does the amoeba belong to?

A. A plant

B. A bacterium

C. An animal

D. A protist

Answer: (D)

Explanation

Amoebas belong to the protists. Calling one an animal confuses its animal-like traits with its group, while plants and bacteria are different groups.