ENVS1401L Exam 2 Review

Match the type of stream habitat with its description

• Relatively deep, fast moving water

• Run

• Deep water that barely moves

• Riffle

• Shallow fast moving water with rocks

• Pool

You collect 10 mL of stream water and make the following dilutions. Arrange the boxes below in order of which you'd expect to have the lowest # of bacteria (1), to the highest # of bacteria (4)

• 1 mL of a 1:10 dilution

• 1 mL of the original, undiluted sample

• 1 mL of a 1:100 dilution

• 1 mL of a 1:1000 dilution

Tags

NGSS.MS-LS2-1

Characterize the following terms or phrases as associated with "Highly eroded" or "low erosion" streams

Groups:

(a) High erosion

,

(b) Low erosion

• Prone to large fluctuations in stream flow (very high rates after rains)

• water with low turbidity

• Highly sloped banks

• Water with high turbidity

• healthy plant life lining banks

• Relatively constant rates of stream flow, even after heavy rain

• Many exposed roots or lack of plants along banks

• Near highly paved areas

• Surrounded by habitat that is relatively unimpacted by pavement

• Gently sloping banks

Imagine you run 10 mL of a 1:1000 dilution of a water sample through a filter, and count 15 bacterial colonies (CFU's) on the resulting filter after incubating them for a week. How many bacteria (CFU's) would be in 1 mL of the original water sample?

Use the formula: (# of CFU's on filter) divided by mL in sample x dilution factor to calculate your answer (sorry there is no divided by symbol available on my keyboard). Type your answer below - do not add units to your answer.

Match the following water quality criteria with the correct description

• Nitrogen

• high levels can be caused by lack of shade, decreases oxygen levels of water

• Turbidity

• High levels caused by overflowing or broken sewage pipes, makes water unsafe for humans

• Temperature

• Measures amount of sediment in water - high levels can clog gills of fish

• pH

• Levels high due to agricultural run-off, causes algae blooms

• Bacteria

• affected heavily by pollution levels - especially acidic or basic substances

Match each word to its definition

• Headwater

• Where a river empties into another, larger body of water

• Biomagnification

• The area of land that drains into a particular body of water

• Mouth

• The beginning of a river - usually formed by smalls streams in higher elevation areas

• Watershed

• The tendency for pollutant levels to increase in organisms as you move up the food chain

A glass of water contains 0.25 L, 9 L of water are used for each minute the shower runs, a sink uses 5L water per minute, and each flush of a toilet is 9L of water.

If a student drinks 4 glasses of water a day, takes a 10 minute shower each day, uses the sink to wash hands and dishes for 20 minutes each day, and flushes the toilet 6 times a day, how much water does she use each week? (don't include units in your answer)

If a farm is applying fertilizer and pesticides to their fields in excessive quantities, you would expect the highest levels of nitrogen to be found ​ (a)   of the farm in a stream that runs adjacent to the farm.

• immediately downstream
• far downstream
• immediately upstream
• far upstream

Tags

NGSS.HS-ESS2-5

A student measures and marks a three meter length of a local stream. He puts a ping-pong ball at the "start" of this 3-meter length and times how long it takes for the ball to float to the "finish" line.

He does this three times and gets three measurements - 6.5 seconds, 7.2 seconds, and 6.9 seconds.

What is the average velocity of this stream?

• 6.87 m/sec

• 2.28 m/sec

• 0.43 m/sec

• 1.31 m/sec

Answer explanation

Don't forget.. you want an answer in meters per second. So you should divide meters (3 m) by the avg. number of seconds the ball takes to travel that distance (6.87)

The ocean contains trace amounts of many chemical pollutants, such as mercury. Put the following animals in order from those which would have the LOWEST levels of mercury in their tissues (1) to those that would have the HIGHEST levels (4). Hint: Orcas eat sea lions which eat fish which eat brine shrimp.

• Brine shrimp

• Fish

• Orcas

• Sea lions

Tags

NGSS.MS-LS2-3