Chapter 22-24: Geologic Time

Question 1

describe the general theory of how the Earth was created

Answer 1

That it was formed at the same time as the rest of the solar system 4.6 billion years ago

Question 2

How old is the Earth? How is this age determined?

Answer 2

4.2+ billion years ago, geologist have used radiometric dating on zicron traces (a mineral in granite) in Australia

Question 3

prokaryotes vs. eukaryotes

Answer 3

• single cell

- multiple cells containing a nuleus

Question 4

How did the Earth’s crust form

Answer 4

cooling of the uppermost mantle,

Question 5

Describe the Precambrian atmosphere and how oxygen got into the atmosphere

Answer 5

hydrogen and helium likely dominated the atmosphere but being so light, they could not stay in the atmosphere because earth’s gravity is not strong enough. Some of the earliest organisms, cynobacteria, used photosynthesis to create food and therefore let off oxygen as as byproduct. billions of this bacteria produced the oxygen in the atmosphere

Question 6

How did early life come to be

Answer 6

3.9-2.5 billion years ago life likely started to form. The Earth’s atmosphere likely contained carbon dioxide, nitrogen, water vapor, methane and ammonia. Around this time as well, earth had may lightning storms making it very warm. making the perfect environment for primordial soup. in which the life may have begun. This environment would have created the amino acids necessary for life to begin

Question 7

transgression

Answer 7

sea level rises and shoreline moves further inland

Question 8

regression

Answer 8

sea level falls and coastline moves seaward

Question 9

what was life like in the middle to late Paleozoic

Answer 9

MIDDLE PALEOZOIC

• predominately dominated by sea creatures
• plants emerged on land
• vascular tissue spreading water allowed earth planets
• seed ferns allowed a more thorough colonization

LATE PALEOZOIC

• fish and sharks
• plants invaded the land
• swampy lands were breeding ground for insects

Question 10

How did life move to land

Answer 10

the development of vascular tissue in plants allowed water and nutrients to circulate through the plant so it could survive outside the water. Seed ferns developed and allowed plants to make their own food and truly live on the land, they reproduced off of seeds so they could spread out on the land colonizing it

Question 11

Major events during the Mesozoic

Answer 11

• break up of Pangaea
• active tectonics in West North America
• sand covered america, then a shallow sea
• mammals and bugs evolve
• cycad plants
• dinosaurs
• flying creatures
• Permian mass extinction

Question 12

Major events in the Cenozoic Era

Answer 12

• ice ages
• volcanic in west north america
• India and Asia collided
• primates
• homo sapiens