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13 Cards in this Set

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What are the criteria for life?

1) Cellular organisms that are carbon- and water-based


2) that contain genetic information sufficient to reproduce


3) that possess the abilities to undergo metabolism


4) that respond to stimuli, and that adapt (through natural selection) to their environment in successive generations.

What did the Miller experiment do?

It created the building blocks of life i.e. amino acids.


What is the name given to a mixture of organic compounds likely to be found in Earth's early evolution?

Primordial Soup

Define prokaryote.

single-celled organism with no membrane bound organelles

A little over a half-billion years ago something happened, perhaps a change in Earth's climate, and life exploded into a wide diversity of complex forms. This began what period?

Cambrian period aka explosion

If life could originate on Earth and develop into intelligent creatures, perhaps the same thing could have happened on other planets. This raises three questions, what are they?

1) Could life originate on another world if conditions were suitable?


2) Will life always evolve toward intelligence?


3) Are suitable conditions so rare that life almost never gets started?

The main requirement for life is the presence of liquid water. What planets does this eliminate?

Moon, Mercury, Venus, the former two are too airless and the latter is too hot to sustain liquid water.

Among Mars, the list of potential habitats in the Solar System now includes at least four other sites: two satellites of Jupiter (Europa and Ganymede) and two of Saturn (Enceladus and Titan)

yup

T/F liquid water could have existed on Mars for a longer period of time than it took for life to evolve on Earth

True. So it is not unlikely that some remains under ice somewhere and that there are microorganisms there.

What does SETI stand for?

Search for Extraterrestrial Intelligence

What extrasolar planets could host life?

1) Kepler-186f has a similar radius to Earth and sits within its habitable zone.


2) Kepler-452b is in the habitable zone and has a Sun-like star but the star is 6 billion years old meaning its brighter than the Sun. Therefore it might be too hot and thus more like Venus.


3) Tau Ceti e is unconfirmed but could be an Earth-like exoplanet orbiting a G-class (i.e., Sun-like) star. Also it is only 11.9 light years from the Sun so thats exciting.

If we ask a question to someone 10 light-years away by radio how long will we have to wait for a reply?

we will have to wait 20 years for a reply

What is the water hole?

Uses radio signals between those absorbed by hydrogen and OH because these make water and we need water for life.