Cell structure：练习题

Which of the following statements about the Golgi body and lysosomes is correct?

In a eukaryotic cell, which structures contain circular DNA and 70S ribosomes?

The smooth endoplasmic reticulum (SER) and rough endoplasmic reticulum (RER) have distinct roles. In a cell specialized for the production of steroid hormones (lipids), how would the relative abundance of these organelles differ from a cell specialized for enzyme secretion?

Which of the following structures is found in both a typical plant cell and a typical prokaryotic cell?

A specific cellular component is synthesized in the nucleolus. This component then passes through the nuclear pores into the cytoplasm. What is the final destination and function of this component?

A student observes a plant cell and notes the presence of plasmodesmata.
State the primary function of these structures and identify the specific part of the plant cell where they are located.

Explain the difference between the terms magnification and resolution, specifically outlining why the maximum resolution of a light microscope is limited by the wavelength of visible light.

Describe the roles of centrioles and microtubules in the organization and movement of chromosomes during nuclear division in animal cells.

A student uses a light microscope to observe a slide of plant tissue. Using a imes 40 objective lens and a imes 10 eyepiece lens, the student views several cells.

(a) Calculate the total magnification used by the student to observe the specimen.
(b) The student measures the diameter of a cell in the field of view as \(80 \text{ mm}\) on a printed photomicrograph. If the actual diameter of the cell is \(40 \text{ µm}\), calculate the magnification of the photomicrograph.
(c) State the formula used to calculate the actual size of a specimen when the magnification and image size are known.

The figure shows two electron micrographs, one of a typical plant cell and one of a typical animal cell.
(a) Identify three structural features visible in the plant cell that are absent in the animal cell.
(b) For one of the features identified in (a), explain how its structure is related to its function in the plant.
(c) Name the structure that connects the cytoplasm of adjacent plant cells through the cell wall.