We all eat right? But have you ever wondered why we eat?

I mean some animals only eat plants, others just eat other animals, and some creatures

eat both plants and meat. But the thing is, all animals, including humans, eat.

And we don't just eat because we're hungry, or bored, or tired, or it tastes good. Although

I could really go for a slice of pizza right now. We eat because we need food to live.

More exactly, we need the energy that food gives our bodies to grow, move, and stay warm.

You've probably figure this out already from the things you've heard about how and when

we eat. Like you've probably heard that breakfast is the most important meal of the day, or

you might know that runners will 'carb load' before a big race. But food is necessary for

all living things, all the time.

You may have noticed that your collection of cool rocks that you have under your bed,

never needs a lunch of club sandwiches and baby carrots. That's because they're nonliving

things.

But food is most definitely a necessity for animals, and plants too. Even though we don't

think of plants as 'eating' because they don't have mouths, they still need food to grow

and repair themselves, just like we do. In fact plants make a nifty model that can help

us understand how the energy from food affects living things.

To see how food affects plants, we can test what happens when they get more or less food.

Plants get most of their food from the sun, water, and carbon dioxide in the air. More

on that another time.

But to test how food affects plants for yourself, you can use liquid plant food, that way you

can control how much food or nutrients a plant gets.

So consider this little investigation.

Say you have two little plastic cups filled with potting soil, and you planted a lima

bean seed in each one, then you give each plant a different amount of food. Plant number

one will be your control, that means that you don't give it any additional food at all,

just a little water and sunlight, and it will do what plants do all on its own. Then you

can make plant two your extra food plant. Ask your parents for some liquid plant fertilizer

and add the recommended amount to plant two.

Now it you kept watering and feeding your plants the same amount for, say, four weeks,

what do you think will happen? Would you expect both of the plants to grow the same amount?

Or would one grow more than the other? If so, which ones?

Well, what you'd find is that plant two grew bigger than plant one because living things

need food to give them energy, so they can repair themselves and stay healthy, and in

this case, grow. So with more food, plant two got more energy, and that allowed it to

grow bigger. Now got eat your vegetables.