Which of the following is responsible for the differences in summer and winter temperature stratification of deep temperate zone lakes?

Which of the following is responsible for the differences in summer and winter temperature stratification of deep temperate zone lakes? 

A) Water is densest at 4°C.
B) Oxygen is most abundant in deeper waters.
C) Winter ice sinks in the summer.
D) Stratification is caused by a thermocline.
E) Stratification always follows the fall and spring turnovers.






Answer: A

In temperate lakes, the surface water is replenished with nutrients during turnovers that occur in the

In temperate lakes, the surface water is replenished with nutrients during turnovers that occur in the 

A) autumn and spring.
B) autumn and winter.
C) spring and summer.
D) summer and winter.
E) summer and autumn.






Answer: A

Turnover of water in temperate lakes during the spring and fall is made possible by which of the following?

Turnover of water in temperate lakes during the spring and fall is made possible by which of the following? 

A) warm, less dense water layered at the top
B) cold, more dense water layered at the bottom
C) a distinct thermocline between less dense warm water and cold, dense water
D) the changes in the density of water as seasonal temperatures change
E) currents generated by nektonic animals





Answer: D

Generally speaking, deserts are located in places where air masses are usually

Generally speaking, deserts are located in places where air masses are usually 

A) tropical.
B) humid.
C) rising.
D) descending.
E) expanding.






Answer: D