I Have Branches

What five-letter word becomes shorter if you add two letters to it?

I am the fifth planet from the sun.

I am the fastest spinning planet in the solar system.

Who am I?

I eat other animals. I have a big mouth.

I am green. I live in water.

Who I am?

I am sweet. I come in different flavours.

I usually have icing on top. I am served at birthday parties.

What am I?

It is white. It has a brown thin skin. 

It grows in the ground. It is a root Vegetable. 

When cutting it make you cry.

What is it?