"); document.writeln("Name: " + studentName + "
"); document.write("Score: " + numCorrect + " / " + numPossible + " (" + scorePercent + "%)"); if (numSubjective > 0) { document.write("     [" + numSubjective + " subjective "); if (numSubjective == 1) document.write("question"); else document.write("questions"); document.write(" not graded]"); } document.writeln("

"); document.writeln("
" + titleString + "

"); document.writeln(""); currentInstruction = 0; currentNarrative = 0; for (i=0; i < numQuestions; ++i) { if (currentInstruction < numInstructions) { if (instructionIndex[currentInstruction] == i) { document.writeln(""); ++currentInstruction; } } if (currentNarrative < numNarratives) { if (narrativeIndex[currentNarrative] == i) { document.writeln(""); ++currentNarrative; } } document.writeln(""); document.writeln(""); document.writeln(""); document.writeln(""); } document.writeln("

"); document.writeln(instructionText[currentInstruction]); document.writeln("
 
"); document.writeln("
"); document.writeln(narrativeText[currentNarrative]); document.writeln("
 
"); document.writeln("

" + prefixText[i] + "

 " + numberText[i] + " 

" + questionText[i]); document.writeln("

"); document.writeln(""); if (listMap.charAt(i) != "1") { document.writeln(""); document.writeln(""); } document.writeln(""); document.writeln(""); if (showNotes) { document.writeln(""); document.writeln(""); } if (showRef) { document.writeln(""); document.writeln(""); } document.writeln("

RESPONSE: 

" + responseText[i] + "

ANSWER: 

" + answerText[i] + "

NOTES: 

" + notesText[i] + "

REF: 

" + refText[i] + "

"); document.writeln("
 
"); document.writeln("
"); document.writeln(""); document.writeln(""); document.write(""); document.writeln("
 
"); document.writeln("Retake Test"); document.write(""); document.writeln("Help"); document.writeln("
"); document.writeln(""); document.writeln(""); document.close(); return(false); } function GetResponse(answerIndex, answer) { var listIndex; var responseText; if (listMap.charAt(answerIndex) == "1") { listIndex = answer.selectedIndex; responseText = answer.options[listIndex].value; } else responseText = StripSpaces(answer.value); return(responseText); } function ScoreAnswer(answerIndex, responseText) { var listIndex; var answerText; answerText = ansMap[answerIndex]; if (qtypeMap.charAt(answerIndex) == "5") return(NumericCompare(responseText, answerText)); else if (qtypeMap.charAt(answerIndex) == "6") return(MultiCompare(responseText, answerText)); else if (responseText.toUpperCase() == answerText.toUpperCase()) return(true); else return(false); } function BuildPrefixText(answerIndex, responseText, isCorrect) { var text; var listIndex; text = "
"
		if (isCorrect)
			text += ""
		else
			text += ""

		if (listMap.charAt(answerIndex) == "1") {
			if (responseText.length == 0)
				responseText = " ";
			text += " " + responseText + " ";
		}

		text += "
" return(text); } function StripSpaces(s) { var len; var i; len = s.length; for (i=len - 1; i >= 0 && s.charAt(i) == " "; --i) len = i; if (len == 0) s = ""; else if (len != s.length) s = s.substring(0, len); return(s); } function TranslateHtmlString(text) { var newText; var replaceString; var position; var length; var breakPos; var skipExtra; var i; newText = ""; position = 0; length = text.length; while (position < length) { skipExtra = 0; breakPos = -1; for (i=position; i < length && breakPos < 0; ++i) { switch(text.charAt(i)) { case '>': replaceString = ">"; breakPos = i; break; case '<': replaceString = "<"; breakPos = i; break; case '&': replaceString = "&"; breakPos = i; break; case '\r': if ((i + 1) < length && text.charAt(i + 1) == '\n') skipExtra = 1; replaceString = "
"; breakPos = i; break; case '\n': replaceString = "
"; breakPos = i; break; case ' ': if ((i + 1 < length) && text.charAt(i + 1) == ' ') { replaceString = " "; breakPos = i; } break; } } if (breakPos < 0) { newText += text.substring(position, length); position = length; } else { if (breakPos > position) newText += text.substring(position, breakPos); newText += replaceString; position = breakPos + 1 + skipExtra; } } return(newText); } function FixMCNotes(notesText, studentText) { var displayText; var searchText; var upperNotes; var charCode; var startIndex; var endIndex; displayText = ""; if (notesText.length > 0) { if (studentText.length > 0) { upperNotes = notesText.toUpperCase(); studentText = studentText.toUpperCase(); charCode = studentText.charCodeAt(0); searchText = "/" + String.fromCharCode(charCode) + "/"; startIndex = upperNotes.indexOf(searchText); if (startIndex >= 0) { startIndex += searchText.length; searchText = "/" + String.fromCharCode(charCode + 1) + "/"; endIndex = upperNotes.indexOf(searchText, startIndex); if (endIndex < startIndex) endIndex = notesText.length; displayText = notesText.substring(startIndex, endIndex); } } if (displayText.length == 0 && notesText.charAt(0) != "/") displayText = notesText; } return(displayText); } function NumericCompare(s1, s2) { var s1Sign; var s2Sign; var tempString; var decimalCount; var decimalPos; var numToDelete; var len; var ch; var i; s1.toUpperCase(); s2.toUpperCase(); if (s1 == s2) return(true); else { s1Sign = 1; s2Sign = 1; tempString = ""; for (i=0; i < s1.length; ++i) { ch = s1.charAt(i); if (ch == "-" && tempString.length == 0) s1Sign = -1; else if ((ch >= "0" && ch <= "9") || ch == ".") tempString += ch; } s1 = tempString; decimalCount = 0; decimalPos = -1; for (i=0; i < s1.length; ++i) { if (s1.charAt(i) == '.') { ++decimalCount; if (decimalPos < 0) decimalPos = i; } } if (decimalCount == 1 && decimalPos >= 0) { len = s1.length; for (i=len - 1; i >= decimalPos; --i) { if (i == decimalPos || s1.charAt(i) == '0') len = i; else break; } if (len < s1.length) s1 = s1.substring(0, len); if (s1.length == 0) s1 = "0"; } numToDelete = 0; for (i=0; i < s1.length; ++i) { if (s1.charAt(i) == "0") ++numToDelete; else break; } if (numToDelete > 0) { if (numToDelete == s1.length) --numToDelete; if (numToDelete > 0) s1 = s1.substring(numToDelete); } ///////////////////////////////////////////// tempString = ""; for (i=0; i < s2.length; ++i) { ch = s2.charAt(i); if (ch == "-" && tempString.length == 0) s2Sign = -1; else if ((ch >= "0" && ch <= "9") || ch == ".") tempString += ch; } s2 = tempString; decimalCount = 0; decimalPos = -1; for (i=0; i < s2.length; ++i) { if (s2.charAt(i) == '.') { ++decimalCount; if (decimalPos < 0) decimalPos = i; } } if (decimalCount == 1 && decimalPos >= 0) { len = s2.length; for (i=len - 1; i >= decimalPos; --i) { if (i == decimalPos || s2.charAt(i) == '0') len = i; else break; } if (len < s2.length) s2 = s2.substring(0, len); if (s2.length == 0) s2 = "0"; } numToDelete = 0; for (i=0; i < s2.length; ++i) { if (s2.charAt(i) == "0") ++numToDelete; else break; } if (numToDelete > 0) { if (numToDelete == s2.length) --numToDelete; if (numToDelete > 0) s2 = s2.substring(numToDelete); } if (s1Sign == s2Sign && s1 == s2) return(true); } return(false); } function MultiCompare(responseText, answerText) { var startIndex; var endIndex; var partialText; responseText = responseText.toUpperCase(); answerText = answerText.toUpperCase(); startIndex = 0; do { endIndex = answerText.indexOf("\r", startIndex); if (endIndex < 0) partialText = answerText.substring(startIndex); else partialText = answerText.substring(startIndex, endIndex); if (responseText == partialText) return(true); startIndex = endIndex + 1; } while (endIndex > 0); return(false); } function FixMTF(f) { var text; var letter; var theList; var listIndex; var number; var i; for (i=0; i < f.length; ++i) { if (f.elements[i].name.indexOf("MTF:") == 0) { number = parseInt(f.elements[i].name.substring(4), 10); theList = f["MTF-" + number + "-1"]; if (theList) { listIndex = theList.selectedIndex; letter = theList.options[listIndex].value; } else letter = ""; text = StripSpaces(f["MTF-" + number + "-2"].value); if (text == "") f.elements[i].value = letter; else f.elements[i].value = letter + "," + text; } } } function AllowReset() { return(window.confirm("Do you want to clear all of your answers?")); } // -->
 
Name: 
 

Populations and Communities



Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
 

 1. 

Which of the following is a biotic factor in the prairie ecosystem?
a.
water
b.
sunlight
c.
soil
d.
grass
 

 2. 

The place where an organism lives and that provides the things the organism needs is called its
a.
habitat.
b.
population.
c.
species.
d.
community.
 

 3. 

The smallest unit of ecological organization is a single
a.
population.
b.
community.
c.
organism.
d.
ecosystem.
 

 4. 

Which of the following is an example of a population?
a.
the cats and dogs in your neighborhood
b.
the bushes and grass in a park
c.
the rocks in a rock collection
d.
the gray wolves in a forest
 

 5. 

If you count 20 beetles in a garden measuring 5 square meters, the population density of the beetles is
a.
100 beetles per square meter.
b.
20 beetles per square meter.
c.
5 beetles per square meter.
d.
4 beetles per square meter.
 

 6. 

Counting the number of organisms in a small area and multiplying to estimate the number in a larger area is called
a.
direct observation.
b.
mark and recapture.
c.
population density.
d.
sampling.
 

 7. 

A group of antelope leaving the herd in search of better grassland is an example of
a.
immigration.
b.
emigration.
c.
increasing birth rate.
d.
decreasing death rate.
 

 8. 

An approximation of a number, based on reasonable assumptions, is called a(n)
a.
biotic factor
b.
limiting factor
c.
immigration
d.
estimate
 

 9. 

The largest population that an environment can support is called its
a.
carrying capacity.
b.
limiting factor.
c.
birth rate.
d.
death rate.
 

 10. 

An organism’s particular role in its habitat, or how it makes its living, is called its
a.
carrying capacity.
b.
ecosystem.
c.
competition.
d.
niche.
 

 11. 

The behaviors and physical characteristics of species that allow them to live successfully in their environment are called
a.
habitats.
b.
limiting factors.
c.
biotic factors.
d.
adaptations.
 

 12. 

The struggle between organisms to survive in a habitat with limited resources is called
a.
competition.
b.
predation.
c.
symbiosis.
d.
parasitism.
 

 13. 

When a jellyfish paralyzes a tiny fish with its poisonous tentacles, the fish is the
a.
predator.
b.
prey.
c.
host.
d.
parasite.
 

 14. 

A close relationship between two species that benefits at least one of the species is called
a.
natural selection.
b.
symbiosis.
c.
adaptation.
d.
competition.
 

 15. 

The Escherichia coli that live in your intestine and help break down food are an example of which type of interaction?
a.
competition
b.
mutualism
c.
parasitism
d.
predation
 

 16. 

An early winter frost preventing further growth in a tomato garden is an example of
a.
carrying capacity.
b.
a limiting factor.
c.
a biotic factor.
d.
indirect observation.
 

 17. 

All of the following are examples of limiting factors EXCEPT
a.
food.
b.
soil.
c.
space.
d.
weather conditions.
 

 18. 

An organism’s habitat must provide all of the following EXCEPT
a.
food.
b.
water.
c.
predators.
d.
shelter.
 

 19. 

The nonliving parts of an ecosystem are called
a.
populations.
b.
organisms.
c.
biotic factors.
d.
abiotic factors.
 

 20. 

To carry out photosynthesis, algae and plants use the abiotic factors sunlight, carbon dioxide, and
a.
soil.
b.
salt.
c.
water.
d.
bacteria.
 

 21. 

Which of the following describes an interaction in which one organism kills and eats another?
a.
competition
b.
symbiosis
c.
predation
d.
mutualism
 

 22. 

Which of the following is an example of a predator adaptation?
a.
a porcupine’s needles
b.
a shark’s powerful jaws
c.
a frog’s bright colors
d.
a plant’s poisonous chemicals
 

 23. 

All the different populations that live together in an area make up a(n)
a.
organism.
b.
community.
c.
species.
d.
ecosystem.
 

 24. 

The study of how things interact with each other and with their environment is called
a.
ecology.
b.
photosynthesis.
c.
community.
d.
biotic studies.
 

 25. 

When a flea is living on a dog, the dog is the
a.
parasite.
b.
host.
c.
predator.
d.
prey.
 

 26. 

Mutualism, commensalism, and parasitism are the three types of
a.
symbiotic relationships.
b.
predation.
c.
competition.
d.
prey adaptations.
 

 27. 

Population density is defined as
a.
an approximation of a number, based on reasonable assumptions.
b.
the number of individuals of a population in a specific area.
c.
the number of individuals moving into a population.
d.
the smallest level of ecological organization.
 

 28. 

A hawk building its nest on an arm of a saguaro cactus is an example of
a.
commensalism.
b.
mutualism.
c.
parasitism.
d.
predation.
 

 29. 

The series of changes that occurs after a disturbance in an existing ecosystem is called
a.
primary succession.
b.
secondary succession.
c.
disturbance succession.
d.
pioneer succession.
 

 30. 

The first species to populate an area where primary succession is taking place are called
a.
secondary species.
b.
primary species.
c.
pioneer species.
d.
succession species.
 

Modified True/False
Indicate whether the sentence or statement is true or false.  If false, change the identified word or phrase to make the sentence or statement true.
 

 31. 

A tapeworm living inside a wolf’s body is a predator. _________________________

 

 32. 

All of the members of a community belong to the same species. _________________________

 

 33. 

Bees and flowers are biotic factors in an ecosystem. _________________________

 

 34. 

The population density decreases as the number of individuals in an area increases. _________________________

 

 35. 

Population size generally increases if the birth rate is greater than the death rate. _________________________

 

 36. 

The carrying capacity is the smallest number of individuals in a population that can live in one area. _________________________

 

 37. 

An insect looks like a leaf, so it blends in with its surroundings and is hard for predators to see. The insect’s characteristic is an example of commensalism. _________________________

 

 38. 

In predation, the organism that kills another organism for food is the prey. _________________________

 

 39. 

Both species benefit in the type of symbiosis called mutualism. _________________________

 

 40. 

The series of changes that occur in an area where no ecosystem previously existed is called primary succession. _________________________

 

Completion
Complete each sentence or statement.
 

 41. 

The part of an ecosystem where an organism lives and feeds is called the organism’s ____________________.
 

 

 42. 

All the biotic and abiotic factors in an area together make up a(n) ____________________.
 

 

 43. 

Prairie dogs, snakes, and grass make up a level of ecological organization called a(n) ____________________.
 

 

 44. 

Water, sunlight, and soil are ____________________ factors in an ecosystem.
 

 

 45. 

Two abiotic factors that are needed for photosynthesis are sunlight and ____________________.
 

 

 46. 

Scientists who study how living things interact with the environment are called ____________________.
 

 

 47. 

The ____________________ method of estimating involves multiplying the number of organisms in a small area to find the number in a larger area.
 

 

 48. 

Observing animal tracks is an example of ____________________ observation, which is used to estimate population size.
 

 

 49. 

A group of zebras breaking off from a herd decreases the size of the herd population through ____________________.
 

 

 50. 

The main way that populations increase in size is through the ____________________ of offspring.
 

 

 51. 

If food is scarce, it becomes a(n) ____________________ factor that prevents population growth.
 

 

 52. 

A lack of places to build nests is an example of ____________________ as a limiting factor for a population of birds.
 

 

 53. 

The thick fur of a polar bear is a(n) ____________________ that allows the bear to live successfully in its environment.
 

 

 54. 

Ticks feed on the blood of mice in a symbiotic relationship called ____________________.
 

 

 55. 

A close relationship between two species that benefits at least one of the species is known as ____________________.
 

 

 56. 

The struggle of two species to occupy a certain niche in an ecosystem is an example of ____________________.
 

 

 57. 

A hawk building a nest on the arm of a cactus without hurting the cactus is an example of the symbiotic relationship called ____________________.
 

 

 58. 

A flea is a parasite that lives on a(n) ____________________ such as a dog.
 

 

 59. 

The study of how living things interact with each other and with their environment is called ____________________.
 

 

 60. 

The type of succession that occurs in an area where an ecosystem has been disturbed, but where soil and organisms still exist, is called ____________________ succession.
 

 

Short Answer
 
 
Use the diagram to answer each question.

pandc_files/i0650000.jpg
 

 61. 

Describe two things the prairie dogs need to live that they obtain from their habitat.
 

 62. 

What is the smallest unit of organization in an ecosystem? Give one example from the diagram.
 

 63. 

Describe one of the prairie dog’s adaptations and how it helps the prairie dog to survive.
 

 64. 

What level of ecological organization do all of the owls in a certain area represent?
 

 65. 

Is the prairie soil a biotic factor or an abiotic factor? Explain your answer.
 

 66. 

Describe three factors that could limit the growth of the prairie dog population.
 
 
Use the diagram to answer each question.

pandc_files/i0720000.jpg
 

 67. 

How was the pheasant population changing at Point A?
 

 68. 

Which letter marks the peak of the pheasant population?
 

 69. 

What happened to the pheasant population between Point B and Point C?
 

 70. 

What are some possible explanations for the change in pheasant population between Point B and Point C?
 

 71. 

In 1990, a large resort hotel was built on the island where these pheasants live. Explain how this might have affected the pheasant population.
 

 72. 

What was the population density of pheasants in 1968, 1976, and 1990?
 

Essay
 

 73. 

Explain why two different species in an ecosystem can share the same habitat but not the same niche.
 

 74. 

Explain the difference between a population and a community.
 

 75. 

Explain the difference between direct and indirect observation in determining population size.
 

 76. 

Define abiotic factor and give four examples.
 

 77. 

Explain why the populations of a predator and its prey often follow regular cycles.
 

 78. 

Classify these examples of symbiosis by type and explain your choice: 1) Inside a human’s intestine live bacteria that make vitamin K; 2) A human picks up bacteria on his or her hands. The bacteria do not cause disease but do feed on the human’s dead skin cells; 3) A tick attaches itself to a human and feeds on the human’s blood.
 

 79. 

An ecologist counts 75 cardinals in an area measuring 15 square kilometers. What is the population density of the cardinals?
 

 80. 

Explain why secondary succession usually occurs more rapidly than primary succession.
 



 
Check Your Work     Reset Help