Transport in animals

Which type of cell is found in the greatest numbers in blood?

• Red blood cell

• White blood cell

• Platelets

What happens to breathing and heart rate during exercise?

• Breathing rate increases and heart rate decreases

• They both increase

• They both decrease

How do you calculate cardiac output?

• Cardiac output = stroke volume / heart rate

• Cardiac output = heart rate / stroke volume

• Cardiac output = stroke volume X heart rate

How do you calculate surface area to volume ratio?

• Surface area / volume

• Surface area - volume

• Surface area + volume

Why is the left wall of the heart have a thicker layer of muscle than the right side?

• To stop the blood flowing backwards

• To push the blood with more force at high pressure so it goes to all body cells.

• To push the blood at high pressure to the lungs.

Why is there a limit to cell size in multicellular organisms?

• As size of cells increase, their surface area to volume ratio also increases meaning substances would diffuse too slowly into the cell.

• As size of cells increase, their volume decreases meaning substances would diffuse too slowly into the cell.

• As size of cells increase, their surface area to volume ratio decreases meaning substances would diffuse too slowly into the cell.

Name 2 human excretory organs.

• Heart and lungs

• Brain and heart

• Kidneys and lungs

What is the name of the liquid part of the blood?

• Platelets

• Plasma

• Red blood cells

Give one adaptation of alveoli for efficient gas exchange.

• Alveoli have a one cell thick lining for a short diffusion pathway.

• Alveoli have a small surface area for fast diffusion of oxygen.

• Alveoli have many a thick lining for a long diffusion pathway.

What do platelets do?

• They stick together and make fibres that make scabs (blood clots) that stop pathogens entering the blood or stop you bleeding to death.

• They form your immune system and destroy pathogens.

• They carry oxygen around the body attached to haemoglobin.