A2.1 Origin of Cells

Evidence suggests Earth's prebiotic atmosphere was primarily composed of _____, ________, and _______ with smaller amounts of ________ and _________.

Evidence suggests Earth's prebiotic atmosphere was primarily composed of nitrogen, carbon dioxide, and water vapor with smaller amounts of methane and hydrogen.

______ compounds are carbon-containing molecules excluding oxides and carbonates

Organic compounds are carbon-containing molecules excluding oxides and carbonates

_______ compounds are all the other compounds that are not organic

Inorganic compounds are all the other compounds that are not organic

There was no oxygen gas or ozone present in prebiotic Earth's atmosphere because oxygen gas was first released into the atmosphere by ________

There was no oxygen gas or ozone present in prebiotic Earth's atmosphere because oxygen gas was first released into the atmosphere by photosynthesis.

In prebiotic Earth, the lack of an ______ _______ resulted in high levels of ultraviolet light entering the atmosphere.

In prebiotic Earth, the lack of an ozone layer resulted in high levels of ultraviolet light entering the atmosphere.

The high concentrations of carbon dioxide resulted in higher temperatures due to the _______ effect.

The high concentrations of carbon dioxide resulted in higher temperatures due to the greenhouse effect.

Oparin and Haldane proposed that _____ generation of organic compounds occurred on early Earth due to energy from uv light, higher temperatures, lightning and volcanic activity.

Oparin and Haldane proposed that spontaneous generation of organic compounds occurred on early Earth due to energy from uv light, higher temperatures, lightning and volcanic activity.

Cell theory states that:

1.

2.

3.

Cell theory states that:

1. Cells are the basic unit of life

2. All organisms are composed of at least one cell

3. All cells come from pre-existing cells

The following were required for the development of the first cells:

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-

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The following were required for the development of the first cells:

- Catalysis

- Self-replication of molecules

- Self-assembly

- The emergence of compartmentalism

Miller Urey attempted to stimulate the conditions of _________ in a laboratory setting

Miller Urey attempted to stimulate the conditions of prebiotic Earth in a laboratory setting

Draw the miller urey experiment. Label all components.

The miller urey experiment showed that _______________________________ by producing ___________

The miller urey experiment showed that at least some of the organic molecules required for life could be spontaneously generated under certain conditions by producing many complex organic molecules, including amino acids

Limitations of the Miller Urey Experiment:

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-

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Limitations of the Miller Urey Experiment:

- Unsure of actual atmosphere of prebiotic Earth

- Did not produce all of the organic molecules required for life

- simulation could not account for all conditions on prebiotic Earth

Cell membranes are formed of ______ bilayers

Cell membranes are formed of phospholipid bilayers

The cell membrane has _____ heads that are _____ (hydrophilic/hydrophobic) and _____ tails that are ______ (hydrophilic/hydrophobic)

The cell membrane has phosphate heads that are hydrophilic and fatty acid tails that are hydrophobic

It has been hypothesized that the first genetic material was trapped within a phospholipid ____ forming a protocell.

It has been hypothesized that the first genetic material was trapped within a phospholipid vesicle forming a protocell.

____ is presumed to be the first genetic material because it can....

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-

-

RNA is presumed to be the first genetic material because it can....

- store genetic material

- self-replicate

- catalyze reactions (ribozymes)

____ is the most recent common ancestor for all organisms on Earth.

Last Universal Common Ancestor (LUCA) is the most recent common ancestor for all organisms on Earth.

The fact that all organisms share the same _____ ______ strongly suggests that all organisms have evolved from LUCA

The fact that all organisms share the same genetic code strongly suggests that all organisms have evolved from LUCA

Evidence suggests that LUCA evolved in the vicinity of hydrothermal vents. List 3 pieces of evidence for this theory:

1. Hydrothermal vents are rich in...

2. Experiments similar to....

3. Some highly conserved genes are involved in...

Evidence suggests that LUCA evolved in the vicinity of hydrothermal vents. List 3 pieces of evidence for this theory:

1. Hydrothermal vents are rich in organic compounds

2. Experiments similar to Miller and Urey's show that the building blocks of life can form from chemicals in the vents

3. Some highly conserved genes are involved in thermophilic metabolism

The minerals and rocks around the earliest fossils have been dated using ______ _______ of uranium, which decays at a steady rate.

The minerals and rocks around the earliest fossils have been dated using radioactive dating of uranium, which decays at a steady rate.

Comparing the number of mutations in genes between species allows scientists to estimate when the two species diverged into separate species. This technique is called _____ _____

Comparing the number of mutations in genes between species allows scientists to estimate when the two species diverged into separate species. This technique is called molecular clocks

Evidence suggests Earth's prebiotic atmosphere was primarily composed of _____, ________, and _______ with smaller amounts of ________ and _________.

Evidence suggests Earth's prebiotic atmosphere was primarily composed of nitrogen, carbon dioxide, and water vapor with smaller amounts of methane and hydrogen.