Chapter 18

Question 1

LUCA

Answer 1

Last Universal Common Ancestor

Question 2

What is LUCA?

Answer 2

“life only comes from life.”

Question 3

Biomolecules

Answer 3

molecules of living organisms organic molecules.
first cells had to arise from nonliving chemicals, inorganic substances. From carbon

Question 4

Primitive Earth’s atmosphere most likely consisted of:

Answer 4

From volcanic eruptions
* Water vapor
* Nitrogen
* Carbon dioxide
* Small amounts of hydrogen, methane, ammonia, hydrogen sulfide, and carbon monoxide
* Little free oxygen

Question 5

Four Stages of Origin of Life

Answer 5

1. Stage 1:
   inorganic -> Organic Molecules “Big life”
2. Stage 2:
   *Organic (Monomer) Molecule -> Organic Polymers
3. Stage 3:
   *(organic polymers) <- Protocell/protobiont/ cell or Plasma membrane
4. Stage 4:
   *Protobont -> Replicas

Question 6

Stage 1: Evolution of Monomers HOW?

Answer 6

1. Outer Space
2. Atmosphere (Oparin-Haldane Hypothesis (1920s))- Outside energy using atmospheric gases.
3. Hydothermal vents

Question 7

Stage 1: Evolution of Monomers Hypothesis

Answer 7

1. Stanley Miller & Harold Urey
2. Miller-Urey Experiment
3. Chemical Evolution at Hydrothermal vents

Question 8

Stanley Miller & Harold Urey

Answer 8

1. gases can react with one another to produce small organic molecules.
2. abiotic (non-living) synthesis (creation) of organic molecules is possible
3. possibly from lightening and UV radiation

ORGANIC SOUP

Question 9

Miller-urey Experiment

Answer 9

Liquid contained small organic modules, which could serve as a monomer can combine and create polymers.

Question 10

Chemical Evolution at Hydrothermal Vents

Answer 10

Minerals that form at deep-sea hydrothermal vents can catalyze the formation of ammonia and even monomers

Question 11

Stage 2: Evolution of Polymers Hypotheses

Answer 11

1.Iron-Sulfur World Hypothesis
2.Protein-First Hypothesis
3.RNA-First Hypothesis

Question 12

Iron-Sulfur World Hypothesis

Answer 12

organic molecules reacted with amino acids to form peptides in the presence of iron-nickel sulfides.

Question 13

Protein-First Hypothesis

Answer 13

It assumes that protein enzymes arose first.
DNA genes came afterwards

Question 14

RNA-First Hypothesis

Answer 14

only RNA to progress toward formation of the first cell or cells.

Question 15

Stage 3: Evolution of Protocells

Answer 15

protocell or protobiont, the hypothesized precursor to the first true cells

A protocell would have an outer membrane and carry on energy metabolism.
Proteinoids are small polypeptides that form microspheres when placed in water.

Question 16

Stage 3: evolution of protocols Hypothesis

Answer 16

Protocell Nutrition
The process would have had to carry on nutrition in order to grow.
Organic molecules formed in the atmosphere and carried into the ocean by rain, simple organic molecules could have served as food.
heterotroph, an organism that consumes preformed organic molecules