Deck 3: Defining Life and Its Origins

Question 1

Which of the following describes the order of emergence of various organisms on Earth?

A)land plants, first prokaryotes, animals, first eukaryotes, humans
B)first prokaryotes, first eukaryotes, land plants, animals, humans
C)animals, first prokaryotes, first eukaryotes, land plants, humans
D)humans, animals, land plants, first eukaryotes, first prokaryotes

Answer 1

B

Question 2

Which of the following is in the correct sequence?

A)the origin of self-replicating molecules -> the abiotic synthesis of small molecules -> the abiotic synthesis of polymers -> packaging of molecules into protobionts
B)packaging of molecules into protobionts -> the abiotic synthesis of small molecules -> the abiotic synthesis of polymers -> the origin of self-replicating molecules
C)the abiotic synthesis of polymers -> the abiotic synthesis of small molecules -> packaging of molecules into protobionts -> the origin of self-replicating molecules
D)the abiotic synthesis of small molecules -> the abiotic synthesis of polymers -> packaging of molecules into protobionts -> the origin of self-replicating molecules

Answer 2

D

Question 3

What is the flow of information that the central dogma refers to?

A)DNA RNA protein
B)DNA protein RNA
C)RNA protein DNA
D)RNA DNA protein

Answer 3

A

Question 4

Which of the following would you take into account if you wanted to define viruses?

A)Viruses are between the biotic and abiotic worlds.
B)Viruses are able to live outside of a host organism.
C)Viruses are able to synthesize their own proteins.
D)Viruses are able to remain unchanged.

Question 5

Why was ATP a primary molecule in connecting energy-releasing and energy-requiring reactions in early cells?

A)because it was the only molecule available to transfer energy
B)because of its versatility and efficiency in transferring energy
C)because of its structure
D)because of its attraction to energy

Question 6

Why do living organisms have the potential for errors (mutations and/or variations) in their development?

A)so that organisms may contribute to evolution
B)so that organisms may live unchanged
C)so that organisms may die unchanged
D)so that organisms may contribute to reproduction

Question 7

Which property of RNA makes some RNA molecules able to act as catalysts?

A)They are single-stranded molecules that can fold into very specific shapes.
B)They are single-stranded molecules that cannot fold into very specific shapes.
C)They are double-stranded molecules.
D)They are double-stranded molecules that can fold into very specific shapes.

Question 8

Alexander Oparin and John Haldane postulated that the early atmosphere was a reducing atmosphere. Why was this prediction an important one?

A)because the molecules contain the maximum possible number of protons that can be easily donated in reactions that lead to synthesis of complex molecules
B)because the molecules contain the minimum possible number of electrons that can be easily donated in reactions that lead to synthesis of complex molecules
C)because the molecules contain the maximum possible number of protons that can be easily accepted in reactions that lead to synthesis of complex molecules
D)because the molecules contain the maximum possible number of electrons that can be easily donated in reactions that lead to synthesis of complex molecules

Question 9

Which of the following factors is the most important requirement in order for life to emerge?

A)the presence of liquid water
B)the presence of air
C)the presence of soil
D)the presence of sunlight

Question 10

Which of the following contribute to evolutionary change over time?

A)changes in RNA
B)changes in DNA
C)changes in proteins
D)changes in cells

Question 11

If a condenser is analogous to the Miller-Urey experiment, which of the following is analogous to primordial Earth?

A)a primeval sea
B)water vapour
C)cold temperature
D)lightning

Question 12

From which of the following processes did the first oxygen molecules come from?

A)aerobic respiration
B)anaerobic respiration
C)the oxidization of water
D)the reduction of water

Question 13

If an electrode is analogous to the Miller-Urey experiment, which of the following is analogous to primordial Earth?

A)water vapour
B)a strongly reducing atmosphere
C)lightning
D)a primeval sea

Question 14

If a warmed flask of water is analogous to the Miller-Urey experiment, which of the following is analogous to primordial Earth?

A)a strongly reducing atmosphere
B)lightning
C)a primeval sea
D)water vapour

Question 15

Which statement best describes the panspermia hypothesis?

A)Life on Earth could have started abiotically.
B)Life on Earth could have started biotically.
C)Different forms of life were present in outer space but these may not have seeded early Earth.
D)Very simple forms of life were present in outer space and these may have seeded early Earth.

Question 16

How old is Earth?

A)about 4.6 million years old
B)about 1 billion years old
C)about 3.6 billion years old
D)about 4.6 billion years old

Question 17

In the 1920s, Aleksander Oparin and John Haldane each made independent proposals about the formation of life on Earth. What did they say about essential organic molecules?

A)that these could not have been made in the absence of life in the conditions on primordial Earth
B)that these could have been made in the presence of life in the conditions on primordial Earth
C)that these could have been made in the absence of life in the conditions on primordial Earth
D)that these could have been made in the absence of life in the conditions on modern Earth

Question 18

What are protobionts?

A)a group of abiotically produced organic molecules surrounded by a membranelike structure
B)a group of biotically produced inorganic molecules surrounded by a membranelike structure
C)a group of biotically produced organic molecules surrounded by a membranelike structure
D)a group of abiotically produced inorganic molecules surrounded by a membranelike structure

Question 19

When were the oldest stromatolites formed?

A)about 2.1 billion years ago
B)about 3.5 billion years ago
C)about 3.9 billion years ago
D)about 4.2 billion years ago

Question 20

What is the importance of the Miller-Urey experiment?

A)It showed that molecules crucial to life could be produced biotically.
B)It showed that molecules crucial to life could be produced abiotically.
C)It showed that molecules not crucial to life could be produced biotically.
D)It showed that molecules not crucial to life could be produced abiotically.

Question 21

Besides the primordial atmosphere, highly reducing conditions would NOT have been found anywhere else.

Question 22

What is indicated by the fact that NOT all eukaryotic cells contain both mitochondria and chloroplasts?

A)Endosymbiosis did not occur at all.
B)Endosymbiosis occurred only in the evolution of mitochondria.
C)Endosymbiosis did not occur in stages.
D)Endosymbiosis occurred in stages.

Question 23

The evolution of multicellularity meant that cells no longer needed to be dependent.

Question 24

What is the name of the process by which mitochondria and chloroplasts probably evolved?

A)endocytosis
B)endosymbiosis
C)exocytosis
D)exosymbiosis

Question 25

The early atmosphere, as proposed by Aleksander Oparin and John Haldane, was an oxidizing atmosphere.

Question 26

Which statement characterizes mitochondria and chloroplasts?

A)Over 60% of the proteins required for mitochondrial or chloroplast function are encoded by genes that are found in the nucleus.
B)Both mitochondria and chloroplasts contain genetic material.
C)Over 80% of the proteins required for mitochondrial or chloroplast function are encoded by genes that are found in the nucleus.
D)Neither mitochondria nor chloroplasts contain genetic material.

Question 27

Which of the following statements does NOT describe eukaryotic cells?

A)Their cytoplasm consists of the cytosol and organelles.
B)They possess a selectively permeable membrane.
C)Their genetic material is localized in the cytoplasm.
D)Their DNA is organized into chromosomes.

Question 28

What does a cell of prokaryotic type lack that differentiates it from a cell of eukaryotic type?

A)a plasma membrane
B)a nucleus
C)DNA
D)chromosomes

Question 29

Which of the following statements does NOT describe prokaryotic cells?

A)They are ten times smaller than typical eukaryotic cells.
B)They vastly outnumber all other types of organisms.
C)They are less versatile biochemically than eukaryotes.
D)They have much less internal membrane organization than eukaryotes.

Question 30

Today's atmosphere is an oxidizing atmosphere. The presence of oxygen allows complex molecules to be formed because oxygen is a strong oxidizing molecule.

Question 31

Earth is approximately 4.6 million years old.

Question 32

Explain why viruses, which can reproduce, evolve over time, and possess genetic material, are still considered NOT alive.

Question 33

What are the major membrane components in a eukaryotic cell?

A)the nuclear envelope, the endoplasmic reticulum, and chloroplasts
B)the nuclear envelope, the endoplasmic reticulum, and mitochondria
C)the nuclear envelope, the endoplasmic reticulum, and the Golgi complex
D)the nuclear envelope, mitochondria, and chloroplasts

Question 34

Important molecules that were present in the reducing atmosphere of primordial Earth were oxygen (O₂), hydrogen (H₂), and methane (CH₃).

Question 35

The evolution of life on Earth was an inevitable outcome of the initial physical, chemical, and biological conditions established by Earth's origin.

Question 36

The energy for the synthesis of organic molecules on primordial Earth came from lightning and intense UV radiation.

Question 37

The energy for the synthesis of organic molecules on primordial Earth came only from lightning.

Question 38

Ribozymes are biological catalysts that are proteins.

Question 39

What is a key trait of a multicellular organism?

A)The organism has many cells.
B)All the organism's cells have the same function.
C)A division of labour exists among the organism's cells.
D)All the organism's cells are similar in shape.

Question 40

Scientists believe that hydrothermal vents could have produced a lot more organic material than generated by the Miller-Urey experiments.

Question 41

What is the difference between a unicellular organism and a multicellular organism (other than the actual number of cells)?

Question 42

Explain how we can be confident that stromatolites were formed by microbial activity.

Question 43

Explain two points that support the extraterrestrial origin of life on Earth.

Question 44

Describe and explain the Miller-Urey experiment.

Question 45

Explain why DNA was favoured by selection as a much better way to store information than RNA.

Question 46

Explain this statement: "Proteins are much more diverse than ribozymes."

Question 47

What is oxygenic photosynthesis, and what is the importance of the development of oxygenic photosynthesis?

Question 48

What does the fact that seven attributes are shared by all life on Earth suggest?

Question 49

Explain the seven characteristics shared by all life-forms.

Question 50

One of the seven emergent properties of life is that organisms exhibit homeostasis. Explain this emergent property.

Question 51

Briefly describe the conditions on primordial Earth and why these were important for the first life to be created.

Question 52

If you were to prove that the RNA molecule was a component of the first cells, how would you do that?

Question 53

Explain the theory of endosymbiosis.

Question 54

Explain how the discovery of ribozymes revolutionized our thinking about the origin of life.

Question 55

Compare contemporary cells and primitive cells with respect to oxidation-reduction reactions.

Question 56

Explain which properties of protobionts are associated with life.

Question 57

What was the importance of clay on early Earth?

Question 58

Explain the advantage of proteins acting as catalysts, and compare them with ribozymes.

Question 59

What are stromatolites?