You've probably heard that some types of bacteria can cause infections and make you sick.
That's true, but that's not all bacteria do. There are an estimated 5 nonillion bacteria on the
planet. 5 nonillion is a 5 with 30 zeros after it, like this:
5,000,000,000,000,000,000,000,000,000,000.
Many of those 5 nonillion bacteria help you much more than they harm you. In fact, bacteria
have many very important functions for life on Earth. In the soil, bacteria help decompose
dead organisms and cycle nitrogen through the ecosystem, which plants rely on. What else
do bacteria do? Bacteria in your digestive system help you digest your food. We even use
some bacteria to make the foods we eat. In yogurt, probiotics are often called "good"
bacteria. They ferment the milk.
AB
If soil did not have bacteria in it, then
A
plants would probably not have enough nitrogen.
B
we probably could not digest our food.
C
plants would probably never die.
D
we could not eat yogurt.