Chapter 18

Question 1

Cosmic evolution

Answer 1

The collection of the seven major phases of the history of the universe, namely particulate, galactic, stellar, planetary, chemical, biological, and cultural evolution.

Question 2

Amino acids

Answer 2

Organic molecules that form the basis for building the proteins that direct metabolism in living creatures.

Question 3

Nucleotide bases

Answer 3

An organic molecule, the building block of genes that pass on hereditary characteristics from one generation of living creatures to the next.

Question 4

Extremophiles

Answer 4

Adjective describing organisms that can survive in very harsh environments.

Example: Mars, Europa, or Titan.

Question 5

Drake equation

Answer 5

Expression that gives an estimate of the probability that intelligence exists elsewhere in the Galaxy, based on a number of supposedly necessary conditions for intelligent life to develop.

Question 6

Water hole

Answer 6

The radio interval between 18 cm and 21 cm the respective wavelengths at which hydroxyl (OH) and hydrogen (H) radiate, in which intelligent civilizations might conceivably send their communication signals.