Chapter 23

Question 1

During the Hadeon Eon there was __ biological life present

Answer 1

-no

Question 2

conditions of the Hadeon Eon

Answer 2

4.6 billion years ago.
-formation of earth
-cooling of surface
-no O2
-oceans forming
-metorites

Question 3

life originated during the _____

Answer 3

archean eon (3.8bya)

Question 4

during the ___, meteorites reduced, and the atmosphere began to accumulate. no O2

Answer 4

archean eon

Question 5

conditions of the Proterozoic eon (2.5 bya)

Answer 5

-origin of photosynthesis
-oxygen present

Question 6

bio life of the proterozoic eon ___

Answer 6

-eukaryotes and multicellular organisms
-photosynthesis-> prokaryotes->O2-> aerobic respiration (multi arise) -> ozone (protects).

Question 7

phanerzoic eon (542 mya) is divided into eras and periods and contains many ____ events

Answer 7

mass extinction events

Question 8

during the phanerzoic eon bio life included

Answer 8

-diverse eukaryotes
-diversity rebounded gradually after mass extinctions

Question 9

causes of mass extinctions

Answer 9

plate tectonic processes (sea levels), increased glaciation, climate change, volcanoes, meteorites.

Question 10

consequences of climate change

Answer 10

-increases earths temp
-melts glaciers
-raises sea levels

Question 11

glaciation drops ___ and makes the Earth temperature ___

Answer 11

-sea levels
-cold

Question 12

volcanoes release ash and sulfur which ___ temperature and weather patterns change

Answer 12

decrease