Module 5 & 6

Question 1

Earth was formed ____ billion years ago

Answer 1

4.55

Question 2

The ‘big bang’ took place ___ bya.

Answer 2

4.6

Question 3

How was Earth’s outer crust formed?

Answer 3

Earth cooling

Question 4

How did oceans form on primitive Earth?

Answer 4

oceans accumulated from water vapour in depressions on Earth’s surface

Question 5

True or false? Ancient Earth had minimal oxygen.

Answer 5

False. Ancient Earth has NO oxygen

Question 6

What important changes took place in Earth’s second atmosphere?

Answer 6

CO2, nitrogen, probably methane and ammonia emitted from volcanic vents

Question 7

What were the four major milestones in the formation of the building blocks of life?

Answer 7

(1) Formation of organic nucleotides and amino acids
(2) Monomers ^^ became polymers
(3) Polymers become enclosed in a membrane
(4) Membrane bound polymers acquire key cell properties (nucleus and organelles to function on its own)

Question 8

Summarize the theory proposed independently by Oparin and Haldene.
Hint: soup

Answer 8

Organic molecules formed spontaneously from inorganic compounds in a primordial soup ( the aqueous solution of organic compounds that accumulated in primitive water bodies of the early Earth).

Question 9

Describe the Reducing hypothesis and the Miller and Urey Experiment.

Answer 9

An apparatus was used to simulate the water cycle, boiling water to mimic evaporation. Water vapour combines with methane, hydrogen, and ammonia to imitate the atmosphere. A condensor cools the atmosphere and produces condensation to imitate rain. Sparks were added to stimulate lightning.
Amino acids and other compounds were produced.

Question 10

What is the Extraterrestrial Hypothesis?

Answer 10

Theory for the origin of the first organic molecules stating they came on a meteorite

Question 11

Describe Wachtershauser’s Deep Sea Vent Hypothesis for the origin of organic molecules.

Answer 11

Hot vents in the bottom of the ocean created perfect conditions for water, metals, methane gas, and hydrogen sulphide to spontaneously form organic compounds, using energy from the vents

Question 12

What substrate did the transformation of monomers to polymers take place?

Answer 12

clay surfaces or tidal ephemeral pools

Question 13

What is a protobiont?

Answer 13

First nonliving enclosed boundary structures (looks like a cell but does not have cellular properties, abiotic, contains cellular molecules)

Question 14

_____ (lipid spheres) may have led to the development of true cells

Answer 14

Liposomes

Question 15

What cellular properties did membrane bound polymers aquire?

Answer 15

Formation of RNA/DNA and metabolism

Question 16

What was the first life on Earth like?

Answer 16

Sulfur bacteria living in an oxygen-less atmosphere and hot ocean with few small landmasses

Question 17

Compare aerobic and anaerobic metabolism.

Answer 17

Aerobic (with oxygen) metabolism

Anaerobic (without oxygen) metabolism

Question 18

When do we see a rise in oxygen levels and why?

Answer 18

2.5 bya; cyanobacteria with photosynthetic abilities began producing oxygen 3.5 bya

Question 19

What is the reason for the delay in the rise of oxygen levels

Answer 19

Banded iron formations; oxidation of ferrous iron produced ferric iron and sediments that contained the oxygen and settled

Question 20

When did the first Eukaryotic cells come into existence and what era was this?

Answer 20

2.0-2.5 bya; Archaean era

Question 21

What ensures that cells are clones and do not compete with each other in a multicellular organism?

Answer 21

Zygotes

Question 22

What is endosymbiosis theory?

Answer 22

The nucleus, chloroplasts, and mitochondria were consumed and later evolved into organelles

Question 23

What are seven types of evidence for Endosymbiosis theory?

Answer 23

Mitochondria and chloroplasts…
Morphology similar to bacteria and archaea; functions similar to aerobic and photosynthetic bacteria; divide by binary fission; contain their own DNA; contain compete transcription and translational machinery (RNA); have electron transport chains; and RNA sequences belong on bacterial branch of tree of life

Question 24

True or false?

Cyanobacteria occur as endosymbionts in the cells of modern organisms.

Answer 24

True

Question 25

Endosymbiosis resulted in a _______ of eukaryotic life

Answer 25

diversity

Question 26

What are the two possible origins of multicellular animals?

Answer 26

Individuals form a colony and single cell divides and stays stuck together

Question 27

What are the three possible reasons for the diversification of eukaryotes?

Answer 27

Genetic changes and environmental changes or predation influencing evolution

Question 28

When did multicellular eukaryotes arise?

Answer 28

1.5 bya in the Proterozoic Eon

Question 29

Multicellularity is associated with the increase in what three things?

Answer 29

size, complexity, and specialization

Question 30

What is the Cambrian explosion and its significance?

Answer 30

The biological big bang characterized by warm, wet climate and oxygen levels above key threshold that gave rise to the evolution of most major invertebrate body forms

Question 31

What are three potential reasons for the large increase in animal diversity in the Cambrian period?

Answer 31

(1) Rising oxygen levels in the atmosphere
(2) evolutionary advances just prior that gave rise to subsequent animals
(3) Predators a key driver of evolutionary biodiversity

Question 32

In what era and period did ancestral plants and arthropods invade land?

Answer 32

Paleozoic era; Ordovician period

Question 33

What was the first terrestrial invertebrate?

Answer 33

myriapods (similar to centipedes) with spiracles for air breathing

Question 34

What was the first land plant?

Answer 34

Bryophytes (liverworts, hornworts, and mosses)

Question 35

What are the 5 key adaptations for living on land?

Answer 35

Obtaining water, preventing water loss, obtaining sufficient energy, coping with variable temperatures, and the ability to support their own weight

Question 36

Plants have changed what four things in Earth’s history?

Answer 36

Atmospheric chemistry, climate, production of soils, and evolution of other consumer organisms

Question 37

What seven major environmental changes drive evolution?

Answer 37

climate/temperature, atmosphere, flooding/weather events, volcanic eruptions, meteor impacts, shifting land masses, and glaciation

Question 38

What is functional extinction?

Answer 38

only a small number of individuals are left and the population is no longer viable

Question 39

What is the natural average extinction rate?

Answer 39

species typically survive 1-10 million years; 9% of species per million years

Question 40

What was the impact of the meteor of the Alvarez Asteroid Theory?

Answer 40

180 km crater, volcanic activity and chemical reactions, tsunamis, rapid increase in temperature, fires, acid rain, dust in atmosphere, and reduced photosynthesis