Animal Transport Systems + Gas exchange OCR A-Level Biology

Why do larger animals need transport systems?

• They have a high surface area to volume ratio.

• Diffusion alone is too slow to meet metabolic demands.

• They have a low metabolic rate.

• They do not need transport systems.

Which factor does NOT contribute to the need for a transport system in multicellular animals?

• Size

• Surface area to volume ratio

• Metabolic rate

• Color of the organism

What is the primary reason diffusion is insufficient for large animals?

• High surface area to volume ratio

• Short diffusion distances

• Low metabolic rate

• Long diffusion distances

In which type of circulatory system does blood pass through the heart only once per circuit?

• Double circulatory system

• Single circulatory system

• Open circulatory system

• Closed circulatory system

Which of the following is a characteristic of an open circulatory system?

• Blood is confined to vessels.

• Blood flows freely in the body cavity.

• Blood passes through the heart twice per circuit.

• Blood flows at high pressure.

What is the main advantage of a double circulatory system over a single circulatory system?

• Lower blood pressure

• Higher blood pressure and faster flow

• Less energy required

• Blood flows freely in the body cavity

Which type of blood vessel has thick muscular walls and a small lumen?

• Vein

• Capillary

• Artery

• Venule

What is the primary function of capillaries?

• Carry blood away from the heart

• Control blood flow into capillaries

• Exchange of gases, nutrients, and wastes

• Return blood to the heart

Which blood vessel contains valves to prevent backflow?

• Artery

• Capillary

• Arteriole

• Vein

What causes plasma to be forced out of capillaries at the arterial end?

• Oncotic pressure

• Hydrostatic pressure

• Osmotic pressure

• Atmospheric pressure