When was the last time you played with blocks?  Do you remember what they looked like?  Some of the blocks were square shapes, while others were round cylinders.  Your blocks may have even been different colors, such as blue, red, and green.  You probably made many different types of buildings with the blocks.  Some of your buildings may have been tall and wide, while others may have been short and thin.

Look blocks - let's build a tower

Living things, or organisms, are also built from "blocks."  These "blocks" are very small and come in many shapes.  When the "blocks" are put together in different ways, they make different types of living things.  These "blocks" are called cells.  Not all blocks have the same shape, and not all cells have the same shape either.

I bet you can list the many ways that animals and plants are different.  You may say that animals can usually move around, while plants are stuck in the ground where they are planted.  Animals will eat and drink food, while plants soak in sunlight, water and chemicals from the soil.  These differences mean that animals and plants need to be composed of, or made up of, different kinds of cells.

Not only am I prettier but I'm smarter than the plants too

Animal cells, or the cells that make up animals, are round in shape.  Just as your brain helps you think and move, animal cells have a nucleus that helps plan and direct what they do.  Animal cells also have mitochondria, which help the cell turn the food you eat into energy.  Finally, the cell is wrapped in a cell membrane, which acts like its skin.  Each of these cells come together to help the animal live.

Plant cells, or the cells that make up plants, are shaped like squares.  They also have a nucleus, mitochondria, and cell membrane.  The plant cell, however, has three extra pieces: cell wall, large vacuole, and chloroplasts.  The cell wall is thick, giving the cell membrane extra help holding the cell together.  There is the large vacuole, which is like a large bubble that holds extra water, in case it does not rain for while, or if someone forgets to water the plants.  Then finally plant cells have chloroplasts that soak in sunlight, which the cell uses to make sugar.  That is why plants cannot grow in the dark.  If there is no sunlight, the plant cannot make sugar to use as food.

Animal and plant cells are alike in some ways.  They are both small and both have a cell membrane.  These are similarities.  A similarity is when two different things have parts that are almost the same.  You may have similarities with people in your family.  Perhaps you and your parents have the same color hair, or you all like to eat ice cream.

No, he's Adam

What are some other ways that you and your family members are similar?  Maybe you laugh at the same jokes, or have the same eye color.  How are you and your family members different?  Does someone in your family have a different hair color from you?  Does one person like to eat green beans while you can't stand them?  A characteristic is a part of something that helps you describe what it is like.  When we want to describe a person we will talk about their characteristics, or how they look and act.  We can also describe the characteristics of a cell by talking about its shape, size, and its job in your body.

What did we learn today?  We learned that animal cells are round, and plant cells are square.  There are many similarities between the cells in that they both are very small, and have a cell membrane, nucleus, and mitochondria.  Plants have a few extra pieces in their cells because they cannot get up and walk to get food or water.  The plants soak up sunlight to make sugar, which they use as food.  Would you like to eat sugar just like a plant for all of your meals?  I bet you would!