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Flashcards in Development of Life on Earth Deck (86)
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1

Earths current atmosphere is rich in...

nitrogen, oxygen, argon, and carbon dioxide.

2

what was Earth's early atmosphere composed of?

gases that came from volcanic eruptions

3

What gases are emitted from volcanic eruptions?

water vapor, nitrogen, and carbon dioxide, almost no oxygen

4

As the water vapor in the air _____ it formed the Earth's early oceans

condensed

5

What formed as water vapor in the air started condensed?

Earth's early oceans

6

about 2.5 billion years ago what increased in the atmosphere?

oxygen

7

Why did oxygen increase in the atmosphere 2.5 billion years ago?

the development of a single-celled bacteria called cyanobacteria (algae)

8

Another name for cyanobacteria is...

algae

9

Cyanobacteria were some of the first species to undergo...

photosynthesis

10

Oxygen levels in the atmosphere _______ as soon as cyanobacteria developed and started to undergo photosynthesis

increased

11

As oxygen levels rose, did carbon dioxide levels drop or rise along with it?

drop

12

What is photosynthesis?

the process by which plants use carbon dioxide, water and energy from the sun to create oxygen as well a carbohydrates that are used to make the plants structure

13

_______ is the process by which _____ use carbon dioxide, water, and energy from the sun to create oxygen

photosynthesis, plants

14

In photosynthesis, what do plants use to create oxygen?

carbon dioxide, water, and energy from the sun

15

Oxygen has been steadily _____ since the development of photosynthesis 2.5 billion years ago

rising/increasing

16

In the beginning of the Cenozoic Era there is a sharp increase of oxygen content that corresponds to the...

number and diversity and size of mammals.

17

In the beginning of the Cenozoic Era there is a sharp _____ of _____ content that corresponds to the ____ and ______ and ____ of mammals

sharp, increase, number, diversity, size

18

There seems to be a link between the amount of ______ in the atmosphere and how may _______ are developing on the Earth.

oxygen, mammals

19

For most of Earth' history we don't find any evidence of _____ or ______

life, bacteria

20

In order for life to survive it must have the ability to ______ itself

replicate

21

What do all forms of reproduction require?

DNA

22

A living thing must be able to...

metabolize

23

what does metabolize mean?

to make energy for oneself

24

What does metabolism require?

some sort of cellular structure that allows food and energy to be exchanged

25

Metabolism requires some sort of cellular structure that allows ____ and _____ to be exchanged

food, energy

26

What are the earliest signs of bacterial life on Earth?

stromatolites

27

stromatolites are...

calcium carbonate deposits formed by cyanobacteria

28

Stromatolites are _______ ______ deposits formed by cyanobacteria

calcium carbonate

29

Cyanobacteria are bacteria that underwent ________, and as they developed what?

photosynthesis

- shells of calcium carbonate from secretions of calcium carbonate (kind of how coral is formed) and the calcium carbonate builds up over years and years so we see a fossilized remnant of cyanobacteria

30

all bacteria are ______ celled organisms

single