What is something cells cannot survive without?
Options:
- (A) gas
- (B) Air
- (C) O2
- (D) CO2
- (E) Ca
- (F) O3
- (G) Fe
- (H) He
--
Let's think first: Cells cannot survive without oxygen. And oxygen, O2, is the molecule to do it. Cells cannot survive without O2.... So the answer is [(C)]

What might be stored in limestone?
Options:
- (A) carbonated water
- (B) chemicals
- (C) cigars
- (D) candles
- (E) Energy.
- (F) carbon
- (G) Energy
- (H) fossils
--
Let's think first: Carbon may be stored in sedimentary rock for millions of years. Limestone is a type of sedimentary rock. Carbon might be stored in limestone.... So the answer is [(F)]

Are there organisms simpler than cells.
Options:
- (A) DNA
- (B) plankton
- (C) tiny
- (D) algae
- (E) amoeba
- (F) RNA
- (G) yes
- (H) food
--
Let's think first: Viruses are not cells. Viruses Viruses are the simplest organisms known. Cells are not the simplest organisms.... So the answer is [(G)]

Cells cannot live without what commonly occuring element found on earth?
Options:
- (A) Air
- (B) matter
- (C) Light
- (D) fossil fuel
- (E) oxygen
- (F) carbon
- (G) sunlight
- (H) water
--
Let's think first: Cells cannot survive without oxygen. Survival is to live, to live means hope. Cells cannot live without oxygen.... So the answer is [(E)]

What does not normally lay eggs?
Options:
- (A) swea
- (B) insects
- (C) Mammal
- (D) chickens
- (E) cows
- (F) animals
- (G) parasites
- (H) ducks
--
Let's think first: Platypus females lay their eggs in a burrow. Although the platypus is a mammal, it is bizarre and lays eggs . Mammals do not usually lay eggs.... So the answer is [(C)]

A platypus is an example of _.
Options:
- (A) Marsupial.
- (B) Monotremes.
- (C) insects
- (D) animals
- (E) killing insects
- (F) Amphibian.
- (G) Placental mammal.
- (H) matter vibrating
--
Let's think first: Monotremes are mammals that reproduce by laying eggs. Well, platypuses are mammals, and they lay eggs. Platypuses are monotremes.... So the answer is [(B)]