Multiple Choice Questions (1 Point Each; Total 15 Points)
Astriobiology 1st Exam - 1
Name: Short Answers
HNRS 228 Spring 2002
Examination #1
Multiple Choice Questions (1 point each; total 15 points):
- You have 4 grams of a radioactive element with a half-life of two years. How
many grams of the original element remain after four years.
A4 grams
B3 grams
C2 grams
D1 grams
E0.5 grams
2.How would you estimate the distance in a light year?
AMultiply the speed of light in meters per second by 60
BMultiply the speed of light in meters per second by 3600
CMultiply the speed of light in meters per second by 24
DMultiply the speed of light in meters per second times the number of
seconds in a year to get the number of meters in a light year
EThis is a trick question, a light year isn't a measure of distance
3.What is an Astronomical Unit?
AThe distance to the nearest star
BThe average distance from the Earth to the Moon
CThe average distance from the Earth to the Sun
DA measure of time that light travels
EA generic term for any large distance
4.The center of the universe, the site of the big bang,
ACould be located if we could find a galaxy which is not moving
BIs located in the direction of the constellation Sagittarius
CIs not at any one location
DIs the one point in the universe everything is moving away from
EWas destroyed by the original explosion
5. The Miller-Urey experiment demonstrated that
ALife did not evolve on Earth, rather it came from somewhere else
BPrimordial soup plus energy can produce organic compounds
CLife must have originated in deep ocean vents
DPrimordial atmosphere had the constituents as the current atmosphere
ELife can be produced in a test tube.
6.What happens when a solar nebula collapses?
AIt flattens out
BIt spins faster
CIt heats up
DAll of the above
ENone of the above
7.Using the proper phase diagram from those provided, what phase would carbon
dioxide be at a temperature of -56.4oC and an atmospheric pressure equivalent to that of Earth's at sea level?
AThe carbon dioxide would exist as a liquid
BThe carbon dioxide would exist as a gas
CThe carbon dioxide would exist as a solid
DThe carbon dioxide could be in any phase, solid, liquid or gas
EThe carbon dioxide could be either in a gas or solid phase
8.Earth possesses few visible craters and the moon possesses many. This is because
AEarth formed later than the moon and, therefore hasn't encountered as many meteoroids
BThe Moon doesn't have an atmosphere that could burn up meteorites before impacting
CErosion and plate tectonics have slowly removed evidence of past cratering on Earth
DA, B and C
EOnly B and C above
9.Which of the following concepts are hallmarks of science (i.e. part of the
scientific method)?
AScience is driven by observations and a belief that the world is inherently understandable
BScience progresses through the creation and testing of models designed to explain our observations
CA scientific model is testable
DAll of the above are hallmarks of science
ENone of the above is a valid hallmark of science.
10. Extinction events in geological history are characterized by several common features. Which of the following is NOT common to major extinction events?
ARecovery of species number and diversity
BLarge number of taxa or species lost
CGeological time period for extinction event measured in fewer than a
million years
DNone of the above
11.Protons and neutrons, both known as nucleons are made up of what particles?
AMuons
BPositrons
CElectrons
DQuarks
ENeutrinos
- At which layer of the Earth (using the diagram below) do you find plate tectonics?
A
B
C
D
ENone of the above
13.The following is a definition of life: “Systems possessing the ability of maintaining form and function through ______processes in the face of a changing environment, resulting in homeostasis.” The missing term is which of the following?
ADeregulatory
BPositive Feedback
CNegative Feedback
DOverarching
ENone of the above.
14.The production of ATP via aerobic and anaerobic respiration involves the chemical breakdown of the following?
ACatabolic enzymes
BAnabolic enzymes
CCarbohydrates
DEsters
EAll of the above
15.The valence electrons of the carbon atom are ______?
A6
B5
C2
D3
E4
Short Answer Questions (1 point each; total of 10 points):
16.Rocks that are formed from the cooled magma or lava from a volcano are called igneous rocks.
17.Microbes that inhabit unusually “hostile” environments due to either chemical or physical features are called extremophiles.
18.Rocks that are a changing combination of the other two kinds of rocks and are changed due to pressures, physical and chemical are called metamorphic rocks.
19.There are a number of significant revolutions in the sciences. One of the most important was the Copernican revolution which proposed that the sun was the center of our solar system.
20.Radioactive dating is a type of absolute dating.
21.The different layers of the sedimentary rock provide a type of relative dating.
22.The group of organisms that have cellular structure characterized by nuclei and multiple organelles are called eukaryotes.
23. Water dissociates to produce ions that are either positively charged (H+) or negatively charged (OH-). The resulting concentration of H+ and OH- in solution is extremely important in the biochemistry of cells and the evolution of life on Earth. The scale to describe this concentration of H+ and OH- in solution is called the pH scale.
24. At standard temperature and pressure on the surface of the Earth, water is a liquid in the range of 0 to 1000C.
25.The hypothesis that life came to earth by a process of interplanetary transport via meteors is called panspermia.
Three Short Essay Questions (10 points each; 30 points total; half page response):
26.Select one of the following and develop your response.
A.Define, describe and discuss the theory about the origins of our universe from the Big Bang.
- Define, describe and discuss the theory about the origins of our sun and
planetary system from a gaseous nebula.
27.Select one of the following and develop your response.
A.Describe at least three different ways that scientists can search for life on planets in our solar system.
B.Describe at least three different chemical techniques used in searching for indicators of possible life on a planet in our solar system.
28.Select one of the following and develop your response.
- Describe the Miller-Urey experiment and explain the significance of the
investigation in our understanding of astrobiology.
- Explain the mechanism underlying how enzymes operate in living
systems.
Three Longer Essay Questions (20 points each, total of 60 points; full page response):
29.Select one of the following and develop your response.
A.Define and describe the science of astrobiology. Discuss its goals and its methods.
B.Describe why scientists believe that life could exist on other worlds in our solar system, while also believing that we are unlikely to find intelligent life in our solar system.
30.Select one of the following and develop your response.
- Describe the role of water as a medium in which life might have evolved.
- Explain how major “quantum” changes have affected the evolution of life
on Earth.
31.Select one of the following and develop your response.
A.Discuss the processes by which evolution explains the early origin of life on Earth. This question calls for a discussion of the processes not the evidence in support of the early evolution of life on Earth.
B.Explain the hypothesis that early forms of life existed in an “RNA World”.