動植物細胞：练习题

Which of the following sub-cellular structures is found in both animal and plant cells?

Which of the following factors would decrease the rate of diffusion of oxygen into a cell across its membrane?

A micrograph shows a cell structure with an image size of \(40\text{ mm}\). If the actual size of the structure is \(0.05\text{ mm}\), what is the magnification used?

Bacterial cells are described as being prokaryotic. Which of these statements about bacterial cells is correct?

How is the structure of a root hair cell specifically adapted for its function of taking up water and mineral ions?

Explain why a root hair cell must use active transport rather than diffusion to take up mineral ions from the soil, and describe the specific cellular adaptation required for this process to occur effectively.

A student views a plant cell using a light microscope. If the image of a permanent vacuole is reported to be \( 15\text{ mm} \) long and the magnification is set to \( \times 500 \), calculate the real size of the vacuole in micrometres (\( \mu\text{m} \)).

A student uses a light microscope to observe sub-cellular structures in a plant cell.

a) The real length of the plant cell is \(0.05\) mm. The image of the cell produced by the microscope has a length of \(25\) mm. Calculate the magnification used by the student. (2 points)
Use the equation: \(\text{magnification} = \frac{\text{size of image}}{\text{size of real object}}\)

b) Name two sub-cellular structures that are found in plant cells but not in animal cells. (2 points)

c) The student wants to observe the internal structure of a ribosome. Explain why they would need to use an electron microscope rather than a light microscope. (1 point)

Multicellular organisms grow and develop through the process of mitosis and cell differentiation.

a) Before a cell can divide, it must undergo a period of growth. Describe the changes that occur within the cell during this growth phase and the subsequent process of mitosis. (3 points)

b) Human stem cells can be used to treat certain medical conditions.
i) Contrast the capabilities of embryonic stem cells with adult stem cells found in bone marrow. (1 point)
ii) Evaluate the use of embryonic stem cells in medicine. Include one potential benefit and one ethical concern in your answer. (2 points)

c) In plants, stem cells are found in the meristem tissue. Explain one advantage of using meristem tissue to produce clones of a plant. (1 point)