B3.2 運輸（生物體）：练习题

A plant cell is placed in a solution with a lower water potential than its cytoplasm. What is the immediate effect on the cell?

The mass flow hypothesis explains the movement of sap in the phloem. Which statement best describes the driving force and direction of this movement?

Which structural feature of xylem vessels is essential for withstanding the negative pressure (tension) generated during the transpiration stream?

How do the structural features of capillaries optimize efficient exchange of substances between blood and tissues, considering the typical pressure gradient?

Explain the primary function of xylem vessels in plants, considering the properties of water that facilitate this process.

The transport of materials is essential for the survival of multicellular organisms.
(a) Compare the structural features of arteries and veins in the mammalian circulatory system.
(b) Explain the role of cohesion and adhesion in the transport of water within the xylem of plants.

The efficient transport of substances is vital for the survival and function of multicellular organisms. In mammals, the circulatory system is highly specialized for this purpose.

a) Compare the structure of arteries, capillaries, and veins, highlighting at least two structural differences for each type of vessel that are directly related to their specific functions.

b) Explain how the heart generates and maintains the pressure gradients necessary for blood circulation through both the pulmonary and systemic circuits.

c) Discuss the role of various factors, such as vessel diameter, blood viscosity, and total vessel length, in regulating blood flow and pressure within the circulatory system.