a thin layer of skin or TISSUE in the body of an animal or human
The cornea is a membrane that covers the human eyes.

a living thing, often one that is small
Forests are home to loads of plant life and millions of organisms.

a particle having energy but no mass or electric charge
Plants use light photons to convert it to energy.

the natural coloring of a plant or animal
The dog's fur has a naturally pink pigment.

to think about something and guess what is possible or likely
Since she never talks, we can only speculate what she is thinking.

a substance that is found in some foods, such as bread and potatoes, that your body changes to energy
Most people get the necessary starch for their diet from potatoes, rice, or bread.

to start a process
Watching the film triggered a childhood memory.