Homework answers / question archive / Question 1 1 / 1 pts What can negatively affect the ability of some organisms to build a hard shell?    A rise in pH levels     A drop in pH levels     Sea-level rise     Ocean warming     Question 2 1 / 1 pts How do toxic chemicals (like PCBs and DDT) affect marine food webs?    Organisms that are higher in the food web (food chain) concentrate these substances in their flesh

Question 1 1 / 1 pts What can negatively affect the ability of some organisms to build a hard shell?    A rise in pH levels     A drop in pH levels     Sea-level rise     Ocean warming     Question 2 1 / 1 pts How do toxic chemicals (like PCBs and DDT) affect marine food webs?    Organisms that are higher in the food web (food chain) concentrate these substances in their flesh

Biology

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Question 1

1 / 1 pts

What can negatively affect the ability of some organisms to build a hard shell?

  

A rise in pH levels

   

A drop in pH levels

   

Sea-level rise

   

Ocean warming

 

 

Question 2

1 / 1 pts

How do toxic chemicals (like PCBs and DDT) affect marine food webs?

  

Organisms that are higher in the food web (food chain) concentrate these substances in their flesh.

   

They concentrate in producers, but decrease with each successive level in the food web.

   

These toxins are removed from food webs when predators eat affected fish.

   

They biodegrade in the food web in 1 to 5 years.

 

 

Question 3

1 / 1 pts

What can cause the ocean surface acidity to increase? 

  

Biomagnification

   

Eutrophication

   

Sea level rise

   

Increased Carbon Dioxide emissions

 

 

Question 4

1 / 1 pts

Cleaning oil spills with chemicals (dispersants) has what affect on the marine environment?

  

They wash oil out to deeper waters where it is less harmful.

   

They tend to give oil-degrading bacteria a "head start" in the biodegrading process.

   

They help the fish and birds recover, but not the environment itself.

   

They can cause more harm than good.

 

Question 5

0 / 1 pts

What causes corals to expel their symbiotic dinoflagellages, a phenomenon known as coral bleaching? 

  

An increase in water temperature for a few weeks.

  

An increase in sound pollution.

   

Sediment run-off from land.

   

The use of cyanide to collect fish for the pet trade industry.

 

 

Question 6

0 / 1 pts

Why are estuaries some of the most polluted habitats?

*Choose ALL correct answers

  

There is little regulation regarding the management of estuaries.

   

Pollution washes down rivers and enters the ocean at estuaries.

   

Estuaries often contain harbors, with their potential for oil spills.

   

They are near-shore so it is easy for illegal dumping to occur.

 

 

Question 7

0 / 1 pts

How does nutrient run-off from land ultimately affect coastal marine waters?

  

It depletes the free oxygen causing fish deaths.

   

It causes algal blooms, which dramatically increase the numbers of plankton feeding fish populations.

   

It lowers the transparency of water, killing off attached seaweeds.

   

It increases macro-algae production and stimulates kelp forest growth and distribution.

 

 

Question 8

1 / 1 pts

Adding Iron to the ocean may reduce atmospheric Carbon Dioxide by increasing  photosynthesis but.....

  

it is unclear how much Carbon Dioxide is being removed from the surface and brought to the deep ocean. 

   

adding iron also changes the ocean's pH levels.

   

it is just a theory and no experiments have been done yet.

   

it does not work in marine (saltwater) ecosystems.

 

 

Question 9

1 / 1 pts

Many of California's natural estuaries have been converted into harbors and marinas.  

  

True

   

False

 

 

Question 10

1 / 1 pts

Which below is a toxic heavy metal pollutant that is found in seafood and can cause severe neurological consequences to unborn children and infants? 

  

DDT

   

Chlorinated Hydrocarbons

   

Mercury

   

PCBs

 

 

Question 11

1 / 1 pts

What is the largest source of oil entering the ocean?

  

Extraction of petroleum

   

Transportation of petroleum

   

Consumption of petroleum

   

Natural seeps

 

Chapter 18

 

Question 12

1 / 1 pts

What do we now do to prevent oil spills. 

* Choose ALL correct answers

  

satellite monitoring of oil platforms and tankers

   

reduction in our global demand for oil

   

upgraded crew testing and training

   

redundant fail-safe systems on oil platforms

   

double-hull oil tankers

 

 

Question 13

1 / 1 pts

All of the following statements about oil spills are true except

  

Crude oil is ultimately biodegradable.

   

Crude oil spills are generally larger and more frequent than spill of refined oil.

  

Refined oil has components added, which make it more deadly than crude oil.

   

Spills of crude oil are disruptive for longer periods of time than spills of refined oil. 

 

Question 14

0 / 1 pts

How can scientists infer what past climate conditions were like?

  

Comparing carbon concentrations in various oceanic layers

   

Studying past historical maps and trade routes

   

Comparing oxygen levels of surface and deep, slow moving water

   

Examining marine sediments from core samples

 

 

Question 15

0 / 1 pts

What have we learned from past efforts to clean up oil spills along the coast?

  

Spraying oil-eating bacteria is the quickest way to remove the spilled oil

   

Leaving it alone in some cases may be the best response

   

Chemical dispersants work best along coastal areas

 

Steam cleaning the rocks with high pressure water is best for a fast recovery