About 25 of the 92 natural elements are known to be essential to life. Which 4 of these 25 elements make up approximately 96% of living organisms?
- carbon, sodium, hydrogen, nitrogen
- carbon, hydrogen, nitrogen, oxygen
- oxygen, hydrogen, calcium, nitrogen
- carbon, oxygen, phosphorus, hydrogen
Which of the following are qualities of any good scientific hypothesis?
- It is testable
- It is falsifiable
- It produces quantitative data
- It produces results that can be replicated
I and II
Plants convert ____
- sunlight to chemical energy
- chemical energy to mechanical energy
- sunlight to mechanical energy
- mechanical energy to chemical energy
If an atom has a charge of +1, which of the following must be true?
- It has the same number of protons as electrons
- It has one more electron than it does protons
- It has one more proton than it does electrons
- It has two more protons than neutrons
Atoms have no electric charge because they have ______
- an equal number of protons and electrons
- an equal number of charged and uncharged subatomic particles
- uncharged neutrons in their nuclei
- an equal number of protons and neurons
A localized group of organisms that belong to the same species is called a ____
What makes lipids/fats hydrophobic?
- the carboxyl group at one end of the molecule
- presence of relatively nonpolar C-H bonds
- the glycerol moiety
- their long carbon skeleton
Which of the following categories includes all others in the list?