n. a center part of something from which other parts can grow
The tree''s stem carries water and nutrients from the roots to the leaves.

n. an animal, plant, human, or any other living thing
Every living organism needs some kind of food to survive.

adj. easily damaged, broken, or harmed
His fragile body suffered many injuries, so he quit football.

n. an animal or plant that is related to another, similar animal or plant
Which animal is the closest relative of dinosaurs?

n. the weight or force that is produced when something presses or pushes against something else
They will use water pressure to clean the dirt off the roof.

v. to produce young plants,
These fish swim a long way up the river to reproduce.

n. a group of animals or plants of the same type that live together
It has been shown, that a larger bee colony will produce relatively more honey.

n. anything that is living, such as an animal, fish, or insect, but not a plant
Squirrels, rabbits, and other creatures live in the forest.

n. a sea animal with a round, transparent body
Be careful because a jellyfish can give a person a painful sting.

adj. strange or not known
UFOs are mysterious flying objects.