Multiple choice

Some of these are useful but many of these are harmful and could kill us. 

  1. Hormones

  2. Enzymes

  3. Bacteria

  4. E. Coli
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Bacteria are single-celled organisms; while many are beneficial for digestion and food production, pathogenic bacteria can cause severe, life-threatening infections. Hormones and enzymes are essential biological molecules produced by our bodies, not external organisms that threaten us.

Keep practicing — related questions