Cypress College ASTR 116 Homework
Astronomy 116, Homework CHAPTER 18 (A) Life in the Universe.
Due:
Print Last, First Name and date on the Scantron in INK. Print your
last name in BLOCK letters on the back of the small Scantron.
Use a No. 2 pencil to fill out the Scantron. Read the chapter.
Look at the videos and simulations in the CD-ROM. Answer all end of chapter
True/False and Fill in the Blank questions. Then answer the following
questions and turn in your Scantron only. Choose the best answer.
1. For how many years did life on Earth consist of only single-celled
life forms?
- a) 100 million years.
- b) 2.5 billion years.
- c) 1 million years.
- d) 30,000 years.
- e) 1 billion years.
2. What important molecules for life were found in the first Miller-Urey
experiment?
- a) Simple DNA.
- b) Fatty acids.
- c) Proteins.
- d) Simple RNA.
- e) Amino acids.
3. What is the approximate rate of star formation in the Galaxy?
- a) 10 stars per month.
- b) 10 stars per year.
- c) 1 star per century.
- d) 1 star per thousand years.
- e) 10 stars per million years.
4. Of the planetary systems that may exist in our galaxy, the text assumed
what fraction may contain a habitable planet?
- a) 1.
- b) 1/10.
- c) 1/50.
- d) 1/100.
- e) 1/1000.
5. Which of the following factors from the Drake equation has a value
that is most difficult to estimate?
- a) Rate of star formation.
- b) Average lifetime of a civilization.
- c) Fraction of stars having a planetary system.
- d) Fraction of life-bearing planets on which intelligence evolves.
- e) Fraction of intelligent-life planets that develop technology.
6. How is a technical civilization defined?
- a) A civilization that can communicate over interstellar distances.
- b) A civilization that has the ability to store information.
- c) A civilization that has developed interplanetary space travel.
- d) A civilization that can construct tools out of raw materials.
7. The Drake equation calculates N. What is N?
- a) The number of planets in our galaxy.
- b) The number of planets with life in the universe.
- c) The number of civilizations in the universe.
- d) The number of technical civilizations in our galaxy.
- e) The number of intelligent life forms in the galaxy.
8. Which of the following appears to be a necessary ingredient for the
development of life, intelligence, and civilization?
- a) Carbon atoms.
- b) An earth-like atmosphere and ocean.
- c) A sun-like star.
- d) Time.
- e) all of the above
9. Around which type of star is there the greatest chance of finding planets
inhabited by intelligent beings?
- a) A main-sequence O star.
- b) A main-sequence K star.
- c) A K-type supergiant.
- d) A white dwarf.
10. Assuming that conditions ripe for life and intelligence abound in
the galaxy, what factor limits the number of Galactic civilizations?
- a) The average survival time for civilizations.
- b) The distance between civilizations.
- c) The distance of civilization from the center of the Galaxy.
- d) The development of electronics.
11. (True/False) Some believe that the organic molecules which led to
life rained down on Earth from space.
12. (True/False) We can say with high confidence that life exists
outside the Earth.
13. When we make contact with extraterrestrials, it is very likely
that
- a. they will look similar to us
- b. they will be wiser than us
- c. conversations by radio will take a long time
- d. they will conquer Earth and put humans in a zoo
- e. they will teach us how to travel faster than light.
14. Earth is an ideal planet for life because
- a. it is the right size
- b. it is in the disk of the galaxy
- c. it has a Moon
- d. it has liquid water on its surface
- e. it’s axis is tilted which causes seasons.
15. One billion years after the big bang, life was not likely to
evolve because
- a. the universe was too hot
- b. the universe was too cold
- c. the universe had not enough heavy elements
- d. not enough time had elapsed for life to evolve
- e. no sunlike stars existed then.