Ch. 6

Question 1

3 lines of evidence to consider for evolution

Answer 1

Stromatolites, microfossils, isotopic evidence

Question 2

Stromatolites are?

Answer 2

Distinctively layered rocks with living microbes interweaved with sediments

Question 3

Stromatolites date life to how many years ago

Answer 3

3.5 billion

Question 4

What suggests that a form of life must predate stromatolites

Answer 4

Photosynthesis

Question 5

Microfossils are?

Answer 5

Very tiny fossils

Question 6

Microfossils give evidence dating back to how many years ago?

Answer 6

3.0 billion

Question 7

Isotopic evidence is?

Answer 7

Life tends to assimilate carbon-12 atoms more easily than carbon-13

Question 8

Isotopic evidence gives evidence dating back how many years ago?

Answer 8

3.85 billion

Question 9

Why is it likely that life originated in water?

Answer 9

No oxygen in the early atmosphere allowed for harsh ultraviolet radiation

Question 10

What are the three possible ways simple organic chemicals manifested?

Answer 10

From space, near the surface of the earth, deep in the ocean

Question 11

The Miller-Urey experiment?

Answer 11

Mimicking the water cycle with lightening. Created amino acids and other organic compounds were found to exist.

Question 12

How did life come from outer space?

Answer 12

Asteroids and comets contained amino acids and chemicals that can survive to the surface

Question 13

What is Panspermia

Answer 13

The relocation of life from elsewhere in the universe to Earth

Question 14

What must life survive to meet the criteria for Panspermia

Answer 14

Initial impact on other planet, harsh space, impact on earth

Question 15

Abiogenesis

Answer 15

How life starts from the basic organic chemicals

Question 16

RNA World hypothesis

Answer 16

RNA came before DNA

Question 17

Organic molecules formed from

Answer 17

RNA forming on clays, RNA replicates in pre-cells, complexity increases to form life, DNA evolves

Question 18

Anaerobic

Answer 18

Organisms that don’t need oxygen

Question 19

The history of evolution starting on earth

Answer 19

Simple anaerobic organisms that developed rapidly in complexity shorty after the earth formed, diversification lead to RNA. Photosynthesis generated oxygen in the atmosphere. Oxygen based life forms dominated

Question 20

Bacteria

Answer 20

single cell organisms that have no cell nucleus

Question 21

Early life was in the form of?

Answer 21

Single cell organisms that reproduced only by cell division

Question 22

Two superkingdoms began before one

Answer 22

Archea and Bacteria came before Eukarya

Question 23

Eukarya are different from bacteria and archea

Answer 23

Only cells with a nucleus and are capable of more complex reproductive strategies

Question 24

Sexual reproduction led to

Answer 24

A huge increase in the diversity of life and the rate of evolution due to genetic mixing

Question 25

Animal life began prolific when

Answer 25

1.2 billion years ago

Question 26

Reasons for explosion in Cambrian era?

Answer 26

oxygen level reached current levels, climate change, genetic diversification, predator efficiency was lacking

Question 27

Plants appear in fossils how many years ago

Answer 27

475 million

Question 28

What is essential for the development of atmospheric ozone

Answer 28

O3

Question 29

When did the “Great Oxidation Event” occur

Answer 29

2.35 billion years ago

Question 30

What is the evidence for the asteroidal extinction of dinosaurs

Answer 30

Large 10km diameter wide asteroid hitting the earth depositing iridium

Question 31

Where did the asteroid hit?

Answer 31

Yacatan Peninsula

Question 32

What were the ramifications of the impact of the asteroid that killed the dinosaur

Answer 32

Pushed material into the atmosphere causing global winter, tsunami, global fires, intense heat, reduced sunlight, mammals rose to dominance

Question 33

Causes for extinction

Answer 33

Volcanic eruption, climate change, mutation, magnetic pole reversal, proximity to a supernova explosion, impact of gamma ray bursts