Short-term climatic changes like the Little Ice Age are poorly understood. One hypothesis for why short-term climatic events occur is ____.
A)plate tectonic activity
B)orbital eccentricity
C)axial tilt
D)precession of the equinoxes
E)variations in solar radiation
Question 2An overall average rate of soil formation might be about ____ per century.
A)2.5 cm
B)25 cm
C)2.5 m
D)25 m
E)250 m
Question 3Eurypterids are a subclass of the cephalopods that are excellent guide fossils.
Indicate whether the statement is true or false
Question 4Orbital eccentricity refers to ____.
A)the need to add a leap day every four years
B)variation in the timing of Earth's equinoxes
C)how much Earth is tilted on it's axis
D)how close Earth is to the Sun
E)how circular or elliptical Earth's orbit is
Question 5Humus ____.
A)is the material always comprising the topmost soil horizon
B)is the dark, organic-rich material formed by bacterial decay
C)is also known as organic litter
D)always includes large amounts of sediments
E)forms from the chemical weathering of the parent rock
Question 6Organisms with endo- or exoskeletons usually have decreased locomotor functions because muscles are restricted.
Indicate whether the statement is true or false
Question 7Which type of glacial deposit was formed by running water?
A)eskers
B)drumlins
C)roche moutones
D)varves
E)erratics
Question 8Clay particles in soil are important in soil development because they ____.
A)hold soil particles apart
B)allow water and gases to enter soil
C)retain water and supply nutrients
D)allow the flow of groundwater
E)they form horizon O in the soil profile