Question

1. which element is found in all living cells on earth?

a. carbon
b. potassium
c. helium
d. oxygen

1. which of the following organisms formed the oldest fossils?

a. trilobites
b. hominids
c. cyanobacteria
d. dinosaurs
use the diagram below for questions 3 - 4.

1. what do the five steepest peaks in the diagram above represent?

a. predator - prey relationships
b. the five mass extinctions in fossil records
c. large speciation events
d. population density

1. what can cause mass extinctions?

a. volcanic eruptions & climate change
b. rising sea levels & habitat destruction
c. illegal hunting & overfishing
d. a & b are correct
e. all of the above

1. the first multicellular organisms appeared during which era?

a. precambrian era
b. mesozoic era
c. paleozoic era
d. cenozoic era

Explanation:

1. Carbon is a fundamental element in organic compounds, which are essential for all living cells.
2. Cyanobacteria are among the oldest organisms, with fossil evidence dating back billions of years.
3. The steepest peaks in extinction - rate graphs typically represent mass extinctions.
4. Volcanic eruptions and climate change (a) can cause mass extinctions. Rising sea levels and habitat destruction (b) can also contribute. Illegal hunting and overfishing (c) mainly affect specific species rather than cause mass extinctions.
5. The first multicellular organisms appeared in the Precambrian era.

Answer:

1. a. Carbon
2. c. Cyanobacteria
3. b. The five mass extinctions in fossil records
4. d. A & B are correct
5. a. Precambrian era