Lesson 3.1: Eras

Question 1

When does the first life started?

Answer 1

4.6 BYA

Question 2

Scientists use the ____________________ to describe major events in the history of life.

Answer 2

geologic timescale

Question 3

Earth’s crust formed about_______

Answer 3

4.2 BYA

Question 4

First prokaryotic life was evident on what year________

Answer 4

4.2 - 3. 8 B.Y.A.

Question 5

Occurence of photosynthesis ______

Answer 5

3.7 B.Y.A

Question 6

Eon is about ____
Supereon are consists of ____ eons hence ____

Answer 6

1 BYA
3
3 BYA

Question 7

what are the 3 eons of Precambrian supereon

Answer 7

Hadean eon
Archean eon
Proterozoic eon

Question 8

3 eras of Phanerozoic eon

Answer 8

Paleozoic, Mesozoic, Cenozoic

Question 9

Phanerozoic eon highlights

Answer 9

-plants
-vertebrates
-dinosaurs
-homosapiens

Question 10

What are the 5 precursors of life

Answer 10

-carbon dioxide
water
hydrogen
methane
ammonia

Question 11

Four major macromolecules

Answer 11

lipids, carbohydrates, nucleic acid, and proteins.

Question 12

Organic Molecules Formed from Simple Precursors what theory is this

Answer 12

Primordial Soup Theory

Question 13

Miller-Urey experiment was performed by _____ and _____ during the year ________

Answer 13

Stanley Miller with the supervision of Harold Urey

1952

Question 14

Explain the setup of miller-urey experiment

Answer 14

*5 L flask
-tungsten electrode (represents lightning)
-Gases ( water, ammonia, methane, hydrogen)

*condenser
-hot and cold water

• sampling and long tube
• synthesized organic molecules
• 500 mL flask boling water (representing the ocean)
• sampling port

*vacuum

Question 15

Result of Miller-Urey experiment

Answer 15

after a week, 10-15% of carbon formed organic compounds

20 amino acids

Question 16

first RNA are formed on _______
characteristic of RNA

Answer 16

clay surfaces

self-replicating molecule
Upon replication, natural selection takes place

Question 17

Adenines can ______ uracil

Explain the bonds between adenine and uracil

Answer 17

Attract
Adenines - sugar phosphate bond
Uracils - sugar phosphate bond

Adenin and uracil - hydrogen bond

Question 18

Once adenine and uracil are linked together ____ forms

This mineral is found in the earth’ crust

Answer 18

RNA
Iron pyrite

Question 19

____ is the origin of life

Answer 19

RNA world

Question 20

If the first cell lived without oxygen, how did they survive?

What type of organism were these?

Answer 20

-they used carbon and energy from organic molecules

-non photosynthetic bacteria and prokaryote

Question 21

About ____BYA there’s a large presence of _____ but upon the presence of _______ and other _______ organism ____ BYA ago

It resulted to

Answer 21

-2- 4.5 BYA
-carbon dioxide
-Cyanobacteria

• the concentration of carbon dioxide decreases, and the concentration of oxygen increases.

Question 22

______ photosynthesis occurs. then diversity and complexity among organisms occur

Answer 22

2 BYA

Question 23

according to the microfossils the first record of prokaryotes are from _______

Answer 23

3.5 BYA

Question 24

Fossil evidence of eukaryotes around ________

Answer 24

1.9-1.4 BYA

Question 25

Highlights in hadean eon provide dates

Answer 25

-formation of earth’s crust (4.2 BYA)
-first prokaryotic life (4.2- 3.8 BYA)

Question 26

Highlights in archean eon

Answer 26

-occurence of photosynthesis (3.7 BYA)

Question 27

Highlights in Proterozoic eon

Answer 27

• O2 accumulation (2.4 BYA)
• oldest eukaryotic fossil (1.5 BYA)
• first multicelluar organism (1.2 BYA)
  -animal inhabit the ocean (517 MYA)