Evolution Of Living Organisms

Question 1

What is the definition of life?

Answer 1

Life is a process capable of self-sustenance, replication, and self-mutation.

Question 2

What is the simplest structure that life is invested in?

Answer 2

A cell.

Question 3

Does life exist on all planets?

Answer 3

No, life does not occur on all planets.

Question 4

Which planets are considered too hot for life to exist?

Answer 4

• Mercury
• Venus

Question 5

Which planets are considered too cold for life to exist?

Answer 5

• Uranus
• Neptune
• Pluto

Question 6

What are the required conditions for the existence of life on Earth?

Answer 6

• Temperatures
• Moisture
• Air
• Suitable conditions

Question 7

What view asserts that life was generated by a supernatural force?

Answer 7

Special Creation.

Question 8

What is the Colonization Theory also known as?

Answer 8

The theory of panspermia.

Question 9

Who was an early proponent of the Colonization Theory?

Answer 9

Svante Arrhenius.

Question 10

What does the Colonization Theory suggest about the origin of life?

Answer 10

Life might have arisen from life forms that came from elsewhere in the universe.

Question 11

What is the Spontaneous Generation Theory?

Answer 11

The theory that life arose abiogenically from non-living matter.

Question 12

Who suggested that living organisms could emerge from soil, straw, or refuse?

Answer 12

Aristotle.

Question 13

What experiment did Francesco Redi conduct?

Answer 13

He proved that maggots on meat arose from eggs deposited by flies.

Question 14

Who disproved the spontaneous generation idea with his experiments?

Answer 14

Louis Pasteur.

Question 15

What did Pasteur show regarding sterile broths and microbial growth?

Answer 15

If sterile air is introduced into a sterile broth, no microbial growth occurs.

Question 16

What is the significance of the period between the formation of Earth and the first life forms?

Answer 16

It was a period for chemical evolution.

Question 17

What was the major source of energy for organic synthesis on primitive Earth?

Answer 17

Sunlight.

Question 18

What were the simple molecules present in the primitive atmosphere?

Answer 18

• Hydrogen
• Methane
• Water vapour
• Ammonia
• Hydrogen sulphide

Question 19

What is chemical evolution?

Answer 19

The formation of complex organic molecules from simple molecules.

Question 20

What is biological evolution?

Answer 20

The formation of a self-sustaining, self-replicating system from complex organic molecules.

Question 21

What are the steps in chemical and biological evolution?

Answer 21

• Formation of monomers
• Polymerisation into biopolymers
• Aggregation into cell prototypes
• Development of reproductive machinery

Question 22

What did Miller’s experiment demonstrate?

Answer 22

Biologically useful molecules could be synthesized from simple molecules using energy sources available in primitive times.

Question 23

What is the formose reaction?

Answer 23

A reaction where two formaldehyde molecules react to form glycoaldehyde.

Question 24

What is the Strecker synthesis?

Answer 24

A process where an aldehyde reacts with HCN to form amino acids.

Question 25

What are purines and pyrimidines synthesized from?

Answer 25

They are synthesized from HCN as a key intermediate.

Question 26

What factors indicate that the primitive atmosphere was reducing?

Answer 26

* Little or no oxygen * Predominantly hydrogen * Presence of iron and carbon

Question 27

What is the prebiotic soup?

Answer 27

The accumulation of biologically important compounds in the absence of oxygen.

Question 28

What is polymerization?

Answer 28

The coming together of several monomers to form complex molecules.

Question 29

What happens during a condensation reaction?

Answer 29

Monomeric units join together, and water is removed.

Question 30

What is the result of a hydrolytic reaction?

Answer 30

The breakdown of a disaccharide into its monomeric units.

Question 31

What is the reaction type when glucose reacts to form a disaccharide?

Answer 31

Condensation reaction ## Footnote This reaction involves the release of water.

Question 32

What kind of reaction breaks down a disaccharide into its monomeric units?

Answer 32

Hydrolytic reaction ## Footnote This reaction requires the addition of water.

Question 33

What condition favors the condensation reaction in a prebiotic soup?

Answer 33

Removal of water by evaporation ## Footnote This helps shift the equilibrium towards the formation of the disaccharide.

Question 34

What are condensing agents used for in chemical reactions?

Answer 34

To enhance reaction efficiency and form high-energy intermediates ## Footnote They help to shift equilibrium in favor of condensation.

Question 35

What is a common example of a condensing agent?

Answer 35

Carbodiimide ## Footnote A specific example is dicyclohexyl carbodiimide used in peptide synthesis.

Question 36

Name two other examples of condensing agents that could have been present in prebiotic conditions.

Answer 36

* Cyanogen (N≡C-C≡N) * Cyanamide (N≡CNH2) * Cyanoacetylene (N≡C-C≡CH) * Diaminomaleonitrile ## Footnote These compounds contain high-energy triple bonds.

Question 37

What role do polyphosphates, like ATP, play in biological systems?

Answer 37

They serve as energy sources and condensing agents ## Footnote ATP is crucial for various biochemical processes.

Question 38

What is the main issue with polymerization processes in the presence of water?

Answer 38

Competition by water molecules ## Footnote Water interferes with the coupling process of monomers.

Question 39

How can the concentration of prebiotic molecules be achieved?

Answer 39

* Evaporation to remove H2O * Heating to dryness * Adsorption on mineral surfaces ## Footnote Each method has its advantages and limitations.

Question 40

What are thermal proteinoids?

Answer 40

Copolymers of amino acids synthesized at high temperatures ## Footnote These were produced by researchers like Sidney Fox.

Question 41

What is a significant limitation of using high temperatures in polymer synthesis?

Answer 41

Potential decomposition of peptides ## Footnote Critics argue that such temperatures may not have been present in the early Earth environment.

Question 42

What is coacervation as proposed by Oparin?

Answer 42

Spontaneous separation of aqueous solutions of polymers into droplets ## Footnote This process leads to the formation of protobionts.

Question 43

What are protobionts according to Oparin?

Answer 43

Droplets with a membrane that encapsulate catalytic molecules ## Footnote These are considered precursors to living cells.

Question 44

What is the outcome when protobionts reach a certain size?

Answer 44

They break into smaller droplets ## Footnote This allows for the potential replication of catalytic functions.

Question 45

What is the significance of ribozymes in the debate of protein vs. nucleic acid evolution?

Answer 45

They suggest that RNA enzymes may have predated protein enzymes ## Footnote This adds complexity to understanding the origin of life.

Question 46

What is the role of the ozone layer in Earth's history?

Answer 46

It serves as a shield against UV rays ## Footnote The ozone layer formed after significant oxygen production by photosynthetic organisms.

Question 47

What was the initial reducing agent used in early photosynthesis?

Answer 47

H2S ## Footnote This was later replaced by water as a more abundant reducing agent.

Question 48

How did organisms adapt to the scarcity of essential nutrients?

Answer 48

By developing enzymatic systems to synthesize substances from simpler precursors ## Footnote This led to the evolution of energy-producing metabolic pathways.