Question 1

During the Carboniferous Period,

Accepted Answer

A)   the carbon dioxide cycle started to operate for the first time
B)   carbon-rich meteorites impacted the Earth
C)   the first carbon-based life appeared
D)   land was covered with dense forests with the appearance of the first insects and amphibians

Question 2

The "oxygen crisis" occurred around

Accepted Answer

A)   2 billion years ago
B)   3.5 billion years ago
C)   2.5 billion years ago
D)   4 billion years ago

Question 3

Why is the claim of the discovery of microfossils controversial?

Accepted Answer

A)   they are found in rocks from the Hadean Eon
B)   it is not clear whether they are of biological or mineral origin
C)   the rocks they are found in are probably contaminated by terrestrial bacteria
D)   they are too small to be of biological origin

Question 4

In the original Miller-Urey experiment it was assumed that carbon and nitrogen in the early atmosphere were present as

Accepted Answer

A)   carbon dioxide (CO₂)  and nitrogen (N₂) 
B)   carbonates (CO₃⁻)  and nitrates (NO₃⁻) 
C)   methane (CH₄)  and ammonia (NH₃) 
D)   carbon and nitrogen atoms

Question 5

The oldest hominid so far discovered dates back to

Accepted Answer

A)   540 million years ago
B)   65 million years ago
C)   a few thousand years ago
D)   6 to 7 million years ago

Question 6

One of the first large organisms to develop the means to live on land were probably

Accepted Answer

A)   plants
B)   insects
C)   reptiles
D)   mammals

Question 7

If a fossil were to be discovered which was 3.7 billion years old this would tell us that life on Earth must have arisen

Accepted Answer

A)   exactly 3.7 billion years ago
B)   at least 3.7 billion years ago
C)   less than 3.7 billion years ago
D)   much later than 3.7 billion years ago

Question 8

Chemical reactions which remove oxygen from the atmosphere are known as

Accepted Answer

A)   oxidation reactions
B)   hydrolysis reactions
C)   precipitation reactions
D)   acid-base reactions

Question 9

Microfossil evidence suggests that life

Accepted Answer

A)   originated when the Earth formed 4.6 billion years ago
B)   originated about 3.4 billion years ago
C)   existed 3.85 billion years ago
D)   existed and was well established by 3.4 to 3.5 billion years ago

Question 10

The "top-down" approach to creating artificial life starts

Accepted Answer

A)   in the laboratory with the raw ingredients of life, and seeks to reproduce life in much the same way that it presumably originated billions of years ago
B)   with a complex organism and then removes cells that are not absolutely necessary
C)   with existing organisms and genetically strips them down, then tries to rebuild them into new species
D)   with animal cells and attempts to clone them

Question 11

An explosion of genetic diversity similar to that which occurred during the Cambrian Period hasn't happened recently, most likely because

Accepted Answer

A)   evolution of life on Earth is no longer occurring
B)   such an explosion can occur only for simple organisms and not complex ones
C)   there are no more ecological niches available to allow this to happen
D)   of the widespread presence of efficient predators that make it much more difficult for entirely new organisms to appear

Question 12

What was one reason that RNA was eventually replaced by DNA as the molecule of choice for storing genetic information?

Accepted Answer

A)   the bases that make up DNA became much more common
B)   DNA is far more stable than RNA
C)   DNA can catalyze its own replication
D)   the double helix of DNA is better able to correct errors in replication

Question 13

One type of early protocell (pre-cells)  probably consisted of small droplets of

Accepted Answer

A)   water
B)   clay
C)   lipids
D)   nucleic acids

Question 14

Microfossils found in northwestern Australia in 2011 appear to have been

Accepted Answer

A)   photoheterotrophs
B)   chemoheterotrophs
C)   photoautotrophs
D)   chemoautotrophs

Question 15

Why are clay surfaces good at promoting the formation of biological polymers?

Accepted Answer

A)   they are the only types of material monomers will stick to
B)   they bring monomers close together, allowing them to react with each other
C)   they are very common on the Earth
D)   clays are made of biological polymers

Question 16

The Cambrian Explosion began approximately

Accepted Answer

A)   2.1 billion years ago
B)   542 million years ago
C)   1.2 billion years ago
D)   65 million years ago

Question 17

The first living organisms probably resembled

Accepted Answer

A)   single-celled eukaryotes
B)   multicellular eukaryotes
C)   single-celled prokaryotes
D)   multicellular prokaryotes

Question 18

Current evidence suggests that life on Earth

Accepted Answer

A)   originated in shallow ponds on land
B)   was delivered from elsewhere in meteorites
C)   was deliberately planted by an advanced civilization
D)   originated close to deep-sea volcanic vents or underground

Question 19

Impacts of large asteroids on the Earth's surface generally result in

Accepted Answer

A)   localized destruction close to the impact area
B)   the destruction of most but not all life on Earth
C)   the formation of Moons
D)   total destruction of all life on Earth

Question 20

Based on current scientific evidence, what is the likelihood that life on Earth was created by some omnipotent being?

Accepted Answer

A)   very unlikely but not impossible
B)   impossible
C)   certain
D)   very likely

Exam 6: The Origin and Evolution of Life on Earth

Based on current scientific evidence, what is the likelihood that life on Earth was created by some omnipotent being?

Correct AnswerverifiedShow Answer

One type of early protocell (pre-cells) probably consisted of small droplets of

Correct AnswerverifiedShow Answer

The oldest hominid so far discovered dates back to

Correct AnswerverifiedShow Answer

An explosion of genetic diversity similar to that which occurred during the Cambrian Period hasn't happened recently, most likely because

Correct AnswerverifiedShow Answer

What was one reason that RNA was eventually replaced by DNA as the molecule of choice for storing genetic information?

Correct AnswerverifiedShow Answer

Chemical reactions which remove oxygen from the atmosphere are known as

Correct AnswerverifiedShow Answer

If a fossil were to be discovered which was 3.7 billion years old this would tell us that life on Earth must have arisen

Correct AnswerverifiedShow Answer

Current evidence suggests that life on Earth

Correct AnswerverifiedShow Answer

In the original Miller-Urey experiment it was assumed that carbon and nitrogen in the early atmosphere were present as

Correct AnswerverifiedShow Answer

The first living organisms probably resembled

Correct AnswerverifiedShow Answer

Why is the claim of the discovery of microfossils controversial?

Correct AnswerverifiedShow Answer

Microfossils found in northwestern Australia in 2011 appear to have been

Correct AnswerverifiedShow Answer

The "top-down" approach to creating artificial life starts

Correct AnswerverifiedShow Answer

During the Carboniferous Period,

Correct AnswerverifiedShow Answer

Impacts of large asteroids on the Earth's surface generally result in

Correct AnswerverifiedShow Answer

Why are clay surfaces good at promoting the formation of biological polymers?

Correct AnswerverifiedShow Answer

The Cambrian Explosion began approximately

Correct AnswerverifiedShow Answer

The "oxygen crisis" occurred around

Correct AnswerverifiedShow Answer

One of the first large organisms to develop the means to live on land were probably

Correct AnswerverifiedShow Answer

Microfossil evidence suggests that life

Correct AnswerverifiedShow Answer

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