Biology questions.

I am trying to fill out a study guide for my Environmental Life Science final coming up. Here are a few questions I am having trouble with I hope someone can help me

1. What three chemical elements are present in all living organisms?

2. What is the additional chemical element in proteins?

3. What is the major cause of carbon monoxide?

4. How are bacteria classified?

5. How are protozoans classified?

6. How are algae classified?

7. On a daily basis, which biological clock dictates your activity?

8. What is S.A.D.?


Ok thats all if you can't answer them all thats ok I just am stuck on these and need help. Much thanks!

SAD

1. Hydrogen, Carbon, Oxygen.

3. Combustion.

8. Seasonal Affective Disorder.

At a guess like!

the opposite of being happy

sorry, to actually help, the first question one of them is water.

Water's not a chemical element.

Very true! Thank you all for the help. Keep the answers coming.

Circadian Rhythm/Clock

Volcanoes

1. What three chemical elements are present in all living organisms? oxygen, carbon, hydrogen

3. What is the major cause of carbon monoxide?
incomplete combustion


8. What is S.A.D.?
seasonal affective disorder (see www.sada.org.uk/whatis.htm)

2. nitrogen i think...