3e) Which blood vessels bring oxygen to all the body cells and carry out waste? A arteries
B veins
C capillaries

4) Marcus measured his pulse rate while he was sitting still and then after doing different types of physical activities. These are his results.

Sitting still: 72 heartbeats per min
Running on the spot: 120 heartbeats per min
Playing football: 150 heartbeats per min
Digging in the garden: 80 heartbeats per min
Riding a bike: 110 heartbeats per min

4e) Explain how Marcus could make this a fair test.

f) Write a conclusion for Marcus findings.

1.2 The respiratory system

1) Use the words in the box to complete the sentences. You will use some words more than once.

Choices: blood, ribs, lungs, nose, carbon dioxide, oxygen and mouth.

We breathe in air through our _mouth_ (1) or _nose_(2). The air we breathe in contains _oxygen_(3) gas. The air moves down the _windpipe_(4) and into our _lungs_(5). The _carbon dioxide_(6) in the air then moves from the (7) into the (8). We breathe out air that contains _carbon_dioxide_(9) gas. The _ribs_(10) protect our respiratory system.

If you know the answer or think I'm wrong, just type "1) (your answer)".​