Lecture 19

Question 1

How old is the Earth?

Answer 1

4.6 billion years old

Question 2

Where did the oxygen in are atmosphere come from?

Answer 2

Organisms doing photosynthesis

Question 3

Cenozoic
Characteristics:
Types of organisms:

Answer 3

Age of mammals

Question 4

Mesozoic
Characteristics:
Types of organisms:

Answer 4

Age of Dinosaurs

Question 5

Paleozoic
Characteristics:
Types of organisms:

Answer 5

Age of visible fossils
Hard shells and bones preserved
Life well documented
Climate changes can be seen

Question 6

Hadean
Characteristics:
Types of organisms:

Answer 6

Lots of volcanic eruptions
No liquid water
Primitive Bacteria

Question 7

Archaeon
Characteristics:
Types of organisms:

Answer 7

Age of Primitive cells
Few rocks or fossils survive
No oxygen in air/no ozone
Cells disorganized because of solar radiation

Question 8

Proterozoic
Characteristics:
Types of organisms:

Answer 8

Air chemistry is 100%
Oxygen build up=ozone
Cells become complex and specialized in larger bodies

Question 9

Early Earth:

Answer 9

Dim Sun
Hotter Earth
No Oceans
No oxygen in air
NO LIFE

Question 10

Earth Now:

Answer 10

Hotter sun
Cooler Earth
Vast Oceans
Lots of oxygen
LIFE

Question 11

Volcanic steam + comets =

Answer 11

water

Question 12

Life =

Answer 12

Ability to reproduce

Question 13

Organic Molecule that unzips and copies itself, to transfer cell info ________

Answer 13

DNA

Question 14

Early cells ate chemicals ______ and each others (animals) before learning to use sunlight _________.

Answer 14

Chemosynthesis

Photosynthesis

Question 15

First photosynthesis took place _______ years ago

Answer 15

3.8 billion