CH.6-Origin of Life/Earth's Geological History

Question 1

Did Earth’s prebiotic atmosphere have oxygen?

Answer 1

No

Question 2

What was Earth’s prebiotic atmosphere composed of?

Answer 2

CO2
Water vapour
Nitrogen gas (N2)
Methane (CH4)
Ammonia (NH3)
Hydrogen gas (H2)
Carbon monoxide CO
Hydrogen sulfide (H2S)

Question 3

Did Earth’s prebiotic atmosphere have an ozone layer?

Answer 3

No

Question 4

T or F: Earth’s atmosphere today has ozone layer

Answer 4

True

Question 5

What are the steps that may have led to origin of first simple unicellular organisms?

Answer 5

1) Abiotic synthesis of small organic molecules (monomers) ==> Amino acids, nucleotides
2) Creation of macromolecules (polymers) from monomers ==> Proteins, nucleic acids
3) Packaging macromolecules into lipid membranes (protocells)
4) Self-replicating molecules within protocells

Question 6

What is the Primordial Soup Hypothesis and who made it? What were the requirements?

Answer 6

By Oparin and Haldane - Conditions on Earth were good for formation of small organic molecules IF AND ONLY IF:
1) No O2 available to create reducing environ. to promote addition of electrons to form larger molecules
2) Source of E
3) Chemical building blocks: water, ions, dissolved gases

Question 7

What experiment performed to test Primordial Soup? Successful? Why?

Answer 7

Miller and Urey - Yes, bc simple organic molecules were formed (amino acids)

Question 8

Since Oparin & Haldane:

Answer 8

1) Volcanic-atmosphere hypothesis
2) Meteors transporting organic molecules from space
3) Deep sea hydrothermal vents

Question 9

T or F: Polymers from Monomers - Polymers will form w/o help from enzymes if temp is high enough for rx

Answer 9

True

Question 10

Packaging organic polymers into protocells: What are vesicles

Answer 10

Simple lipid membranes

Question 11

Packaging organic polymers into protocells: Simple lipid membranes (___) may have formed around _____. This would have created the ____

Answer 11

vesicles - organic polymers - first intracellular environment

Question 12

T or F: Living organisms don’t need to be able to replicate themselves

Answer 12

False

Question 13

What was most likely encoded as RNA in first living organisms?

Answer 13

Genetic info

Question 14

RNA is key to synthesis of…

Answer 14

Proteins

Question 15

Can some RNA molecules perform enzymatic fcts?

Answer 15

Yes

Question 16

As RNA sequences become longer, they become less ___

Answer 16

Stable

Question 17

RNA is more stable than DNA?

Answer 17

No. DNA is more stable

Question 18

Order in chronological order:
a) First prokaryotes (single-celled)
b) First multicellular eukaryotes
c) Cambrian explosion (increase in diversity)
d) Colonization of land by fungi, plants, animals
e) First eukaryotes (single-celled)

Answer 18

a) First prokaryotes (single-celled)
b) First eukaryotes (single-celled)
c) First multicellular eukaryotes
d) Cambrian explosion (increase in diversity)
e) Colonization of land by fungi, plants, animals

Question 19

Name Energy source and carbon source for:
1) PhotoAUTOTROPH
2) ChemoAUTROTROPH
3) PhotoHETEROTROPH
4) ChemoHETEROTROPH

Answer 19

1) PhotoAUTOTROPH =
Light (energy), CO2 and HCO3- (carbon)
2) ChemoAUTROTROPH =
Inorganic chems (H2S, NH3), CO2 and HCO3-
3) PhotoHETEROTROPH =
Light, Organic compounds
4) ChemoHETEROTROPH =
Organic compounds, organic compounds

Question 20

Oldest known fossils of living organisms are: prokaryotic or eukaryotic

Answer 20

Prokaryotic

Question 21

What is the oldest known fossils of living organisms? Were they prokaryotic?

Answer 21

Stromatolites (formed by ancestor of cyanobateria) - prokaryotic

Question 22

What are the cause of modern-day stromatolites?

Answer 22

Cyanobacteria

Question 23

In the proposed biological timeline, what took up most of it? How does it compare to humans?

Answer 23

Prokaryotes - Humans were small portion

Question 24

First living organisms?

Answer 24

Prokaryotes

Question 25

T or F: The 1st prokaryotes were all autotrophic and their first source of carbon was organic

Answer 25

False, first source of carbon was INORGANIC

Question 26

Oxygen levels increased bc of:

Answer 26

Photoautotrophic prokaryotes

Question 27

The presence of ___ in the atmos allowed for evolution of single celled aquatic ____

Answer 27

Oxygen - eukaryotes

Question 28

Single celled eukaryotes evolved from ___

Answer 28

prokaryotic ancestor

Question 29

Mitochondria are found in all ___ cells

Answer 29

eukaryotic

Question 30

Mitochondria have double membrane: name them

Answer 30

Smooth outer Complex inner

Question 31

T or F: Mitochondria don't have their own DNA and ribosomes

Answer 31

False

Question 32

Function of mitochondria

Answer 32

Cellular respiration

Question 33

How does mitochondria perform cellular respiration?

Answer 33

1) Use E from glucose, fatty acids, amino acids 2) Make adenosine triphosphate ATP

Question 34

Are chloroplasts in all eukaryotic cells?

Answer 34

No, in plants and some protists (algae)

Question 35

T or F: Like mitochondria, chloroplasts have 2x membrane and own DNA and ribosomes

Answer 35

True

Question 36

What pigment is chloroplast? Where is it found?

Answer 36

Chlorophyll found in internal structures "Thylakoids"

Question 37

Function of chloroplast and how

Answer 37

Photosynthesis - Transform light E into bond E forming glucose molecules

Question 38

What is Endosymbiont Theory? What does it prove?

Answer 38

Cell living withing another cell - Proves that Mitochondria & Chloroplasts (organelles in euk cells) have OWN DNA AND RIBOSOMES different from ones in cytoplasm

Question 39

Endosymbiont Theory proved that it occured 2 times: what are they?

Answer 39

1) Bacterium that could perform aerobic cellular respiration (became euk mitochondria) 2) Bacterium could perform photosynthesis (became euk chloroplasts)

Question 40

The additions in mitochondria and chloroplasts are 2 distinct ___ gene transfer

Answer 40

Horizontal

Question 41

What is the oldest known fossil of multicellular eukaryotes?

Answer 41

Red algae

Question 42

Choose and fill in blank: The first animals were aquatic/inaquatic invertebrates similar to ___ modern day ___

Answer 42

Aquatic - sponges

Question 43

What made the diversity of aquatic animals increase?

Answer 43

Cambrian explosion

Question 44

Majority of life was in ___ habitats

Answer 44

water/moist

Question 45

What helped liv. orgs. colonize land?

Answer 45

1) Formation of ozone layer (reduce UV radiation) 2) Evolution of traits to reduce reliance of water

Question 46

What is the sequence of events?

Answer 46

1) Prokaryotes 2) Atmospheric oxygen 3) Single-celled eukaryotes 4) Multicellular eukaryotes 5) Animals 6) Land plants 7) Paleozoic 8) Mesozoic 9) Cenozoic 10) Humans

Question 47

Land plants are before animals. T or F

Answer 47

False - animals then plants

Question 48

Order: Cenozoic, Paleozoic, Mesozoic

Answer 48

1) Paleozoic 2) Mesozoic 3) Cenozoic

Question 49

We can examine genetic diversity at many levels: Population, ___, and 3 domains: __, __, ___

Answer 49

species - Archaea, bacteria, eukarya

Question 50

Which are autotrophic organisms: Producers, consumers or decomposers

Answer 50

producers

Question 51

Which are heterotrophic organisms: Producers, consumers or decomposers

Answer 51

Consumers & decomposers

Question 52

Producers, consumers or decomposers: Make up the base of a food web by synthesizing organic molecules from which all other organisms will depend upon (O2 and organic mutriends for consumers AND organic nutrients for decomposers)

Answer 52

Producers

Question 53

Producers, consumers or decomposers: Must ingest producers/consumers to acquire carbon and energy

Answer 53

Consumers

Question 54

Producers, consumers or decomposers: Digest organic molecules left by living organisms and absorb the breakdown products to acquire carbon and energy

Answer 54

Decomposers