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The Journey of an Oxygen Molecule

Questions: 5

Grade: 5

Words: 86

Text

Text & Questions

Text, Questions & Answers

One day, an oxygen molecule entered our body through the nostrils. It traveled down a windpipe and reached two big air-filled spaces, the lungs. In the lungs, it met tiny air sacs and was quickly grabbed up by a red blood cell. The red blood cell carried the oxygen molecule to the heart, which sent it to all parts of the body. After it was used up, it became a carbon dioxide molecule and was carried back to the lungs, and then we breathed it out.

Question 1

What does the oxygen molecule become after it is used up?

Carbon monoxide

Nitrogen

Hydrogen

Carbon dioxide

Explanation. After the oxygen molecule is used up, it becomes a carbon dioxide molecule.

Helium

Question 2

Where does the oxygen molecule travel to after it enters through the nostrils?

Stomach

Lungs

Explanation. The oxygen molecule travels down a windpipe and reaches the lungs after it enters through the nostrils.

Brain

Heart

Liver

Question 3

What grabs the oxygen molecule in the lungs?

White blood cell

Plasma

Platelet

Red blood cell

Explanation. In the lungs, the oxygen molecule is quickly grabbed up by a red blood cell.

Bacteria

Question 4

Where is the oxygen molecule sent to from the heart?

Back to the lungs

Out of the body

Brain only

All parts of the body

Explanation. The heart sends the oxygen molecule to all parts of the body.

Just to the muscles

Question 5

What happens to the carbon dioxide molecule after it is carried back to the lungs?

It is used again

It becomes an oxygen molecule

It is breathed out

Explanation. The carbon dioxide molecule is breathed out after it is carried back to the lungs.

It is stored in the lungs

It travels to the heart

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