Topic 2.7: Transport Systems Questions

State the role of HDLs (high-density lipoproteins) in transporting cholesterol.

State one structural feature of a phloem sieve tube cell.

Which feature distinguishes a capillary from an artery and a vein?

State one health risk linked to consuming too much sodium (salt).

Identify two possible causes of a high level of blood cholesterol.

What is the role of HDLs (high-density lipoproteins) in cholesterol transport?

What does translocation in the phloem move, and in which direction?

Which chamber of a mammalian heart has the thickest, most muscular wall?

Which structure absorbs water from the soil, giving a large surface area for uptake into the plant?

Which statement correctly describes systolic blood pressure?

State the feature of a capillary wall that allows substances to be exchanged with the tissues quickly.

State the main reason haemoglobin is required in the blood.

Capillaries form a dense network running close to every cell in a tissue. Outline two structural features of capillaries that make the exchange of substances with the surrounding tissues efficient.

State what happens to the water in the xylem immediately after water evaporates from the mesophyll cells of a leaf.

Which of these is a structural feature of a phloem sieve tube cell?

A diet that is consistently high in salt (sodium) most directly increases the risk of:

Which cell, found alongside the sieve tube, supplies the energy to load sugar into the phloem?

Sugar made in the leaves of a plant must reach growing roots and developing fruits. Outline the process of translocation, explaining how sugar is moved from a source to a sink in the phloem.

Draw a labelled flow diagram (a chain of boxes connected by arrows) to show how a diet high in saturated fat can lead to coronary heart disease. Your diagram should name the plaque process and reach the effect on the heart muscle.

The mammalian heart pumps blood around two separate circuits. Explain why blood is pumped through the heart twice for each complete circulation of the body, and state one advantage of this arrangement.