exam 3 ch 18.1

Question 1

the longest eon transition to an oxygenated atmosphere and multicellular eukaryotes evolve

Answer 1

proterozoic eon

Question 2

Atmospheric free oxygen (as a byproduct of photosynthetic
cyanobacteria) levels increased permanently

Answer 2

2.4-2.0 GA the great oxygenation event

Question 3

Oxygen combined with dissolved iron in oceans to form iron oxides, that
precipitated out, forming alternating layers of iron oxides and chert.

Answer 3

banded iron formations (BIF’s )

Question 4

First fossil evidence that fungi may have diverged from other life.
-Evidence from basalt from South Africa contains filamentous fossils, that form mycelium-like structures

Answer 4

2.4 Ga Paleoproterozoic Fungi:

Question 5

-Free oxygen (as a byproduct of photosynthesis) reacted with the methane in the atmosphere
(converting it to CO2) causing a global glaciation

Answer 5

2.3–2.2 Ga Proterozoic snowball Earth event:

Question 6

-The first known major extinction wiped out 99% of life on Earth

Answer 6

2.4–2.0 Ga The Oxygen Catastrophe:

Question 7

Enzyme that reduces molecular oxygen into water

Answer 7

Cytochrome oxidase:

Question 8

8,000 mi from north to south landmass consisting of
major parts of all current continents resulting in major mountain building events

Answer 8

2.1 to 1.8 Ga Columbia (Nuna) Supercontinent:

Question 9

First possible fossil evidence of multicellular eukaryotic
life

Answer 9

2.1 Ga Multicellular eukaryotes:

Question 10

First definitive fossil thylakoids

Answer 10

1.75Ga

Question 11

Membrane-bound compartments found in chloroplasts and cyanobacteria that are responsible for the light-
dependent reactions of photosynthesis

Answer 11

Thylakoids:

Question 12

Definitive multicellular eukaryote fossils.

Answer 12

1.63 Ga:

Question 13

The stromatolites reach their peak ~1.2 Ga, evidence for eukaryotes with plastids

Answer 13

1.6-1.0 Ga Mesoproterozoic:

Question 14

Organelles found in plant and algae cells that are responsible for photosynthesis.

Answer 14

Plastids:

Question 15

Cyanobacteria evolved into

Answer 15

Plastids.

Question 16

The supercontinent that formed from fragments produced by breakup of Columbia (Nuna).

Answer 16

1.26–0.9Ga Rodinia Supercontinent:

Question 17

Mountain building process that occurs when continents collide.

Answer 17

Orogeny:

Question 18

A permanent primary endosymbiosis event in the ancestor of land
plants, red algae, green algae (Archaeplastida clade) via endosymbiosis with a cyanobacteria

Answer 18

1.5Ga Last Plastid-containing Common Ancestor (LPCA):

Question 19

First incorporation of photosynthetic bacteria into another cell

Answer 19

Primary endosymbiosis event:

Question 20

Photosynthetic eukaryotes (unicellular algae) that contain plastids reminiscent of Cyanobacteria

Answer 20

Glaucophytes:

Question 21

”We design and engineer artificial photosynthetic endosymbiosis
between photosynthetic cyanobacteria and budding yeasts.”

Answer 21

Artificial photosynthetic endosymbiosis:

Question 22

First fossils containing sexual spores

Answer 22

1.0Ga First fossils for sexual reproduction:

Question 23

Multicellular Eukaryotic fossils indicate they colonized freshwater.

Answer 23

1.0 Ga Eukaryotes colonize freshwater:

Question 24

First fossils of green seaweed.

Answer 24

1.04 Ga Chlorophyte fossils: