Standard Science Primary 5 Systems

Why does Alexa's pulse rate increase after she runs a 100m sprint?

A To produce more carbon dioxide for her lungs
B To slow down her breathing rate
C To pump more oxygen and digested food to her muscles faster
D To help her muscles cool down
Show Worked Solution

Worked Solution

Step 1: Running requires more energy for muscles. Step 2: Muscles need more oxygen and food to produce this energy. Step 3: The heart beats faster to transport these substances through the blood more quickly.

Correct answer: To pump more oxygen and digested food to her muscles faster

Want more questions like this? Superholic Lab has 10,000+ MOE-aligned questions with full worked solutions.

Start Free Trial — 7 Days Free