Chapter 25.1-25.3 Origin and Diversity of Life

Question 1

When was earth formed?

Answer 1

4500MYA

Question 2

The first 500-700 million years of earth’s history comprised what eon?

Answer 2

Hadean eon

Question 3

How was the atmosphere of hadean’s earth?

Answer 3

A dynamic environment, shifting from fiery and sometimes frozen earth

Question 4

What effect did low CO2 levels have on the temperature?

Answer 4

Earth cooled and became frozen for a period

Question 5

Rodinia

Answer 5

A single supercontinent existed in the Southern Hemisphere during the Proterozoic eon, and broke up into smaller continents in approx. 700 MYA

Question 6

Gondwana

Answer 6

Supercontinent made of all current southern hemisphere that contributed to Pangea

Question 7

Early organisms were thought to be autotrophs with the ability to synthesize complex ____ compounds from simple ______ compounds and later use them as an energy source

Answer 7

Organic, Inorganic

Question 8

The Hadean, Archean, and Proterozoic period makes up what

Answer 8

Precambrian

Question 9

The Phanerozoic eon makes up what percent of earth’s life?

Answer 9

12%

Question 10

What eon contains most of biological history of diversification of multicellular life?

Answer 10

Phanerozoic eon

Question 11

What are the basis of all living organisms?

Answer 11

Organic Molecules

Question 12

What is the most abundant amino acid?

Answer 12

Glycine

Question 13

Autotropic

Answer 13

An organism that can produce it’s own food using light, water, carbon dioxide, or other chemicals

Question 14

Heterotroph

Answer 14

An organism that consumes other organisms in a food chain

Question 15

All oxygen molecules are a result of what?

Answer 15

Photosynthetic oxidation of water

Question 16

What are issues with an the early RNA life theory?

Answer 16

No good source of ribose, challenge to form long chains of RNA nucleotide

Question 17

Microfossils

Answer 17

Fossilized forms of microscopic life

Question 18

The idea that RNA may have been the first nucleic acid to permit self-replication and the fact that ribosomes translate RNA into proteins support what?

Answer 18

RNA world hypothesis

Question 19

For most of the history of life on earth, the only form of living organisms were what?

Answer 19

Single-celled

Question 20

The Miller-Urey experiment demonstrated that

Answer 20

Organic molecules could have originated in the early atmosphere

Question 21

Fossil data indicated that

Answer 21

life may have originated in 3.5 BYA but definitely did so by 3.2 BYA

Question 22

Biomarkers

Answer 22

Organic molecules, which are clearly of biological origin

Question 23

Beginning with a single cell in the Archean eon, life has evolve into 3 monophyletic clades called domains including?

Answer 23

Eubacteria, Archaea, and Eukaryotes

Question 24

Endosymbiosis

Answer 24

Theory that proposes that eukaryotic cells evolved from a symbiosis between different species of prokaryotes

Question 25

The ancient fixation of carbon happens via two main pathways:

Answer 25

Calvin cycle and the Krebs cycle

Question 26

Living organisms incorporate ___ into their cell before any other carbon isotopes?

Answer 26

C12

Question 27

Cyanobacteria, algae, and modern land plants use which of the following pathways for carbon fixation

Answer 27

calvin cycle

Question 28

Which two of the following macromolecules may have composed a vesicle (or bubble) from which living cells arose?

Answer 28

Lipids and proteins

Question 29

Multiple lines of evidence indicates that the first cells were most likely

Answer 29

prokaryotic