The Challenges Of Size

Question 1

Name adaptations of alveoli that make gas exchange efficient

Answer 1

Their walls are one cell thick providing a short distance for diffusion. There are many of them, giving it a large surface area. They are moist, which allow the gases to dissolve, and therefore diffused more easily.

Question 2

Which gas diffuses from the blood in the capillaries, into the air in the alveoli?

Answer 2

Carbon dioxide

Question 3

What passes down its concentration gradient from the alveoli, into the bloodstream?

Answer 3

Oxygen

Question 4

Carbon dioxide is transported around the body dissolved in what?

Answer 4

The blood plasma

Question 5

Platelets

Answer 5

Tiny structures that help the blood to clot

Question 6

plasma

Answer 6

Straw-coloured liquid that blood cells float in. Many materials are transported via being dissolved in plasma. This includes digested food, waste, and antibodies. (Over 90% of plasma is water)

Question 7

White blood cell

Answer 7

Large cells that contain a nucleus. They fight diseases by making antibodies or changing shape to engulf microorganisms

Question 8

Red blood cells

Answer 8

Biconcave cells containing no nucleus and contain haemoglobin (they carry oxygen). They fit though the lumen of the capillary tube one cell at a time