General cell structure: แบบฝึกหัด

What is the primary function of the nucleus within a cell of a marine organism?

In the fluid mosaic model of a cell surface membrane, what is the specific role of carrier proteins compared to channel proteins during the movement of substances into a marine organism's cell?

Which of the following best explains why channel proteins are essential for the selectively permeable nature of the cell surface membrane in marine cells?

What is the primary role of nucleoli within the nucleus of a marine invertebrate cell?

Which statement correctly describes how carrier proteins facilitate the selectively permeable nature of a marine cell membrane?

A drawing of a marine cell has a length of \( 50\text{ mm} \). If the actual length of the cell is \( 100\ \mu\text{m} \), calculate the magnification of the drawing.

Describe the structure of the phospholipid bilayer within the fluid mosaic model and explain why the membrane is described as being fluid.

Explain the specific roles of the rough endoplasmic reticulum and Golgi body in the production and transport of extracellular enzymes in a marine mollusc.

(a) State the primary function of the large permanent vacuole in a marine producer and identify the specific fluid found within this structure. \( [2] \)
(b) Contrast the cell surface membrane and the cell wall in terms of their relative thickness and chemical composition. \( [2] \)

The cell surface membrane is often described using the fluid mosaic model.
(a) Describe the structure of the cell surface membrane, making specific reference to the arrangement of phospholipids and proteins.
(b) Explain how the selectively permeable nature of the membrane allows it to control the movement of ions, such as sodium and chloride, from seawater into the cell.