165 aquatic ecosystem test

Question 1

In a lake experiencing thermal stratification during the summer, the layer with the most extreme temperature gradient is called the:

Answer 1

B) Thermocline (metalimnion)

Question 2

The two main causes of stratification are

Answer 2

C. density and temperature

Question 3

The term “stratification” means

Answer 3

B. to form layers

Question 4

Density of water depends on its

Answer 4

Density of water depends on its

Question 5

Water is its least dense at this temperature:

Answer 5

B. 0°C

Question 6

As water cools below 39°F (4⁰C), it becomes

Answer 6

B. less dense

Question 7

Water is most dense at this temperature

Answer 7

A. 39°F or C. 4°C

Question 8

Winter stratification of lakes remains stable because

Answer 8

C. the ice cover prevents it from mixing

Question 9

Lakes that turnover do so during

Answer 9

D. the spring and fall

Question 10

A lake is most stratified during

Answer 10

C. the summer

Question 11

The zone in a lake that is shallow with rooted plants is called the

Answer 11

B. the littoral zone

Question 12

An example of an emergent plant is

Answer 12

B. cattail

Question 13

The zone of a lake where there is the highest temperature gradient is

Answer 13

C. thermocline/metalimnion

Question 14

The term “anoxic” means

Answer 14

D. without oxygen

Question 15

The open water area of a lake is known as the

Answer 15

D. limnetic

Question 16

The depth at which sunlight is first limited is called the

Answer 16

B. compensation depth

Question 17

Which water type holds the most dissolved oxygen?

Answer 17

C. cold water

Question 18

Which is true about the compensation depth?

Answer 18

B. the rate of respiration exceeds the rate of photosynthesis

Question 19

Which of the following statements about water is true?

Answer 19

B. warm water floats on top of cold water

Question 20

Which lake layer is most likely to become anoxic?

Answer 20

B. the profundal

Question 21

The type of flood control measure that regulates development in the floodplain is

Answer 21

D. zoning

Question 22

Which of the following does NOT cause an increase in flooding?

Answer 22

B. watershed protection

Question 23

Dredging is the responsibility of the

Answer 23

A. USACE

Question 24

One reason wetland delineation is difficult to define is

Answer 24

C. the boundaries are not clear and abrupt, instead they are gradual

Question 25

Delta

Answer 25

F. the mouth of a river where it deposits sediment in a pattern

Question 26

Estuary

Answer 26

H. an area where freshwater and saltwater mix

Question 27

Peat

Answer 27

a type of soil along wetlands that is rich in carbon

Question 28

Ecotone

Answer 28

a transitional area between aquatic and land ecosystems

Question 29

Floodplain

Answer 29

J. the level areas along a river that receives overflow during high water

Question 30

Watershed

Answer 30

A. all of the land whose runoff drains into a river

Question 31

Levee

Answer 31

I. a mound of earth and/or cement used to control flooding

Question 32

Run

Answer 32

an area of river where the flow remains constant

Question 33

Riffle

Answer 33

K. a length of river with small waves from rocks and/or logs

Question 34

Pool

Answer 34

L. an area of river with little to no flow, deeper than rest

Question 35

Scarp

Answer 35

E. the sloped bank of a stream or river

Question 36

Thalweg

Answer 36

C. the lowest point of a river’s channel