1.10.3 The Origin of Life: Life from Nonlife

Question 1

Sydney Fox

Answer 1

• polymerized small organic molecules by simulating conditions of primitive Earth.
• was able to create polymers of amino acids by placing the molecules in drying conditions.
• Clay was found to be an excellent substrate for this polymerization.

Question 2

Miller and Urey

Answer 2

• synthesized small organic molecules in an experiment that reproduced the proposed conditions of primitive Earth.
• simulated conditions by combining NH3, CH4, and water vapor, boiling the mixture, and then subjecting the mixture to simulated lightning.
• Small organic molecules were later collected.

Question 3

primitive earth

Answer 3

• thought to have had large amounts of energy and a reducing atmosphere.
• thought to have consisted primarily of hydrogen-rich
  molecules, such as ammonia (NH3), methane (CH4), and water vapor.

Question 4

Several factors are required to convert an abiotic world into a biotic world

Answer 4

• the synthesis of biological molecules, polymerization of these molecules, collection of the molecules into aggregates, and heredity.

Question 5

The Miller / Urey experiment showed that

Answer 5

• the hypothesized conditions on early Earth could generate organic molecules.

Question 6

Sidney Fox’s experiment showed that

Answer 6

• if the “thin soup” was subjected to drying conditions, dipeptides and polypeptides could form

Question 7

The first person to obtain indirect evidence that organic molecules could have formed on early Earth was

Answer 7

• Miller

Question 8

Many scientists believe that the formation of life from abiotic substances could not occur on modern Earth. The best explanation is that

Answer 8

• the oxidizing atmosphere present today is not conducive to the synthesis of complex organic molecules

Question 9

According to most ideas about the earliest atmosphere on Earth, all of the following gases were present except

Answer 9

• O2

Question 10

It is thought that life originated approximately

Answer 10

• 3.8 billion years ago

Question 11

To simulate the atmosphere that was thought to have been present in early Earth, Stanley Miller and Harold Urey used an apparatus with an atmosphere containing

Answer 11

• hydrogen, ammonia, methane, and water vapor.

Question 12

Which one of the following was not a characteristic of Earth approximately four billion years ago?

Answer 12

• shallow seas