[IB Biology at GHS: Ecology Exam Review Game]

Ecology Review Game Answer Sheet

IB Biology SL 2007


1) The number of niches increases from pioneer species to climax species during succession.

2) Biodiversity increases from pioneer species to climax species during succession.

3) Pioneer Plants / Pioneer Species

4) Climax Community / Climax Species

5) Interspecies Competition occurs as one species replace another during succession.

6) Pioneer Plant Examples (Any type of weed mentioned: Dandylions, Clover, blackberries, scotsbroom) and others: moss, lupine, fireweed, etc…..

7) Pioneer plants of bare rock: Lichens and mosses

8) Mutualism

9) Niche

10) Eutrophication = buildup of nitrates, phosphate and other nutrients in rivers or lakes.  These “fertilizers” cause a rapid growth of algae which consume all the oxygen in the water, killing everything.

11) CFCs (Chloroflurocarbons)

12) (2 damaging effects of UV light on life) 1) Damages cell DNA, causing mutations.  2) Causes cancers (especially of skin.)  3) Causes severe sunburn and eye cataracts.      4) Reduces photosynthesis rates in plants & algae, affecting food chains.

13) In situ conservation = conserving the species in its own habitat.

14) Ex situ conservation = conserving a species by removing the species from its habitat and preserving it in a zoo, game farm, garden, etc.

15) A) Lichen on a rock (an example of primary succession.

16) B) reforestation after a forest fire.

17) 2 examples of soil preparation here: 1) Organic matter added to soil by plants and animals.    2) Decay adds organic matter to deepen soil.   3) Water retention increases as organics are added.    4) Roots prevent erosion.    5) Amount of mineral recycling increases as the soil holds more nutrients.

18) Climax forests have more biodiversity (& niches) than a field.

19) 2 examples of Ex situ Conservation: a) captive breeding     b) zoos      c) seed banks            d) botanical gardens

20) 2 examples of In situ Conservation: a) National Parks  b) nature reserves    c) urban greenspaces    d) Wildlife Refuges

21) 2 advantages of insitu conservation:  1) Species remain adapted to their habitats   2) Greater genetic diversity is conserved.   3) Animals maintain natural behaviors   4) Species can still intereact, helping to conserve the whole ecosystem.

22) Recently extinct species:  a) Passenger pigeon (hunted for feathers),   b) dodo (easy to kill, hunted for food),

23) 1 Ethical reason to conserve biodiversity: 1) Every species has a right to live.   2) Wrong to deprive future humans of the biodiversity seen today.  3) Wildlife have cultural importance to local human populations, so it is wrong to destroy it.

24) 1 ecological reason to conserve biodiversity:   1) Species are interdependent (part of food webs), so if 1 goes extinct, the others are impacted.    2) Native species are adapted to local conditions,  whereas alien species that replace them are not as well adapted.     3) Damage to ecosystems can have wide effects, including erosion, flooding, changes to weather.

25) 1 economic argument to conserve biodiversity: 1) New crops, farm animals or pets may be developed from newly found species.    2) Many organisms might be a source of medicines.    3) Ecotourism may provide income for impoverished rural areas.

26) 1 esthetic argument to conserve biodiversity:  1) Natural ecosystems & species are beautiful or give us great enjoyment.    2) Painters, writers & composers have been inspired by nature.

27) Organisms are difficult to classify into 1 specific trophic level if they feed at different levels in different food chains (ex: omnivores).

28) There is so little biomass and low numbers of organisms at higher trophic levels of food chains because so little energy makes its way there (only 1% for a secondary consumer).

29) 2 factors affecting distribution of animal species: a) temperature, b) water, c) breeding sites,  d) food supply, e) territory.

30) 2 factors affecting distribution of plant species: a) temperature,  b) water,  c) amount of sunlight.   d) pH of soil,  e) mineral nutrients.   F) salinity of soil.

31) Intraspecific Competition (snow leopards are the same species)

32) Interspecific Competition (lions and hyaenas are 2 different species)

33) Competitive Exclusion Principle: Only 1 species can occupy a niche at a given time.

34) Carrying Capacity = The maximum number of members of a species the resources and predators in the ecosystem will support at a given time.

35) Random Sample = A method to sample populations randomly so each individual has an equal chance of being sampled.  (Reduces error for the study)

36) Trophic Level = The level in a given food chain in which a specific species “feeds” or obtains its energy.

37) 2 methods to reduce CFCs level in atmosphere: 1) use CFC-free aerosols.   2) Use refrigerators, freezers & air conditioners with safe coolant.   3) Use food- or product- packaging free of CFCs.

38) 1 reason to conserve world’s fish:   1) Major food supply for humans.   2) Parts of major food chains, their loss means disruptions of these food chains.

39) 2 measures to protect fish species from overexploitation:  1) Monitor numbers of fish & their reproductive rates.    2) Set quotas (how many fish can be caught) for species with low numbers.   3) Prevent catch of endangered species.    4) Set minimum size of nets, so young are caught.   5) Ban drift nets which catch many unwanted species.

40) Nutrients can endlessly be recycled through food chains.  Energy can move through a chain only once.

41) 2 consequences of acid precipiation: 1) Conifer trees are very sensitive to low pH (weakens trees).  2) Fish and aquatic insects are sensitive to changes in pH, killing them & disrupting food chains.    3) Acids leach key minerals from soil, making soil less fertile.   4) Acids leach aluminum out of soil. Aluminum in water becomes toxic to fish.

42) 2 methods to prevent acid precipitation: 1) Neutralize all chemical wastes before disposal.   2) Use catalytic converters on engines to prevent release of chemicals to air that can be converted to acids.   3) Convert from engines run on fossil fuels to solar, hydrogen, fuel cells, or wind as energy source.

43) One source of acid precipitation:  1) Burning produces CO2 which can be converted to carbonic acid.   2)  Internal combustion engines (produces either sulfur dioxide which is converted to sulfuric acid or produces nitrogen oxides that are converted to nitric acid.)

44) The precautionary principle states that those responsible for a change to the environment are responsible for proving that the change they put into place wil do no harm. Example: If an industry pollutes the air and potentially causes air temps to rise, the industry is responsible for proving their pollution is harmless.

45) Global warming is an international problem because air pollution in one country can cross boundaries to pollute other countries, and also causes air temperatures worldwide. Climate change likewise sees worldwide affects. Melting glaciers causes sea level rises that are also seen worldwide.

46) Potential consequences of global temperature rise on arctic ecosystems include warming of the permaforst with increased decomposition & release of methane and carbon dioxide. In addtion, species normally found farther south can move north as the temperatures get warmer. As the polar ice cap melts, seals must migrate farther to find sea ice for raising their young and likewise polar bears must search farther for the seals they must eat (often drowning when there is no ice to rest on). Pest species and diseases may migrate into the arctic with moderating temps.

47) B) Bilateral symmetry has two equal halves to their body plan.

48) A) Radial symmetry has the body parts organized in a circle around a central axis. The body can be cut into many equal halves across this central axis.

49) This population age graph shows that the birth rate will increase within 10-20 years as the part of the population that is so large (the 0-20 year olds) reaches reproductive age.

50) B) Endoderm is the innermost layers of body cells that give rise to the inner linings of the circulatory & digestive systems.

51) C) Mesoderm is the middle layers of body cells that give rise to muscles, blood and various body systems.

52) A) Ectoderm is the outermost layers of body cells that give rise to skin, nervous system and external sensory organs.

53) D) Phylum Platyhelminthes has no body segmentation and flattened bodies.

54) C) Phylum Porifera has no body organs, 2 cell layers & needle-like spicules for support. They lack any body symmetry so are said to be asymmetrical.

55) E) Phylum Arthropoda has body segmentation, jointed legs, bilateral symmetry and an exoskeleton.

56) A) Phylum Annelida has bilateral symmetry, segmented bodies & no jointed legs.

57) C) Phylum Cnidaria has radial symmetry (the only one!), jelly bodies and stinging cells to catch food.

58) Many of the producers must be dieing as there is a large amount of energy in the saprotrophs & detritivores.

59) A pyramid of numbers may have a low number of producers when those producers are very large (like trees) and the herbivores are small (like insects).

60) In a pyramid of energy, the producers must always have the most energy, as about 90% of the energy is lost between the producers and the next level above it.

61) Herbivore = plant eater

62) Carnivore = meat eater

63) Omnivores eat roughly equal amounts of meat and plants

64) Detritivore

65) B) Autotroph

66) A) Chemotroph

67) C) Heterotroph

68) D) Saprotrophs

69) Sunlight (the sun)

70) Producer = green plants

71) Primary consumers = herbivores (plant eaters)

72) Secondary consumers = carnivores (meat eaters) - Omnivores are best used in food webs.

73. Food web = manyinterconnected food chains

74. Abiotic (nonliving) factors of environment = water, soil, air, rocks, pH, salinity, etc.

75. Biotic factors of the environment include all living things, plants, animals and fungi (etc.) that are part of the ecosystem.

76. Biosphere = the thin layer of all ecosystems that covers the surface of the earth.

77. Greenhouse gases = the main two are carbon dioxide (CO2) and methane (CH4). Others include sulfur dioxide (SO2), and water vapor.

78. Short wavelengths of light from sun pass thru the atmosphere and strike the earth, warming the earth’s surface. The earth emits heat of longer wavelength. Greenhouse gases act like a lid and trap the longer wavelength energy, heating the air.

79. Two consequences of increased greenhouse effect: a) global warming, b) melting glaciers and polar ice caps, c) rising sea level (expansion of water & melting of glaciers), d) flooding of coastal areas and coral atolls, e) more frequent (more energetic) storms, f) changes in weather patterns, g) diseases (like malaria) move further towards poles

80. One measure to reduce greenhouse effect: a) Restore forests, b) Change from fossil fuels to non-carbon based energy sources, c) Reduce energy consumption (fuel efficient vehicles,  better home insulation, eat locally grown food, etc.), d) spread nutrients (iron) to oceans to promote growth of algae.

81. Parasitism

82. Mutualism

83. Two animal parasites: a) tapeworms, b) flukes, c) leeches, d) ticks, e) fleas, f) lice, g) ringworms, h) athletes foot, etc…..

84. Plant parasite: a) mistletoe, b) dodder, c) paintbrush

85. Example of a mutualistic relationship: a) clownfish & sea anemone, b) boxer crab & sea anemone,  c) coral and calcium-fixing algae,  d) termite & wood-digesting beasties in its gut, e) rhino and tick birds, f) other reasonable answer.

86. Homo = genus name.

87. For a population to increase, C) Natality + immigration > mortality + emigration

88. sapiens = species name.

89. Canis lupus = B) binomial nomenclature

90. Mice Population = 60    (10 X 30 / 5)

91. One benefit of classifying organisms: a) aids species identification, b) helps predict whether similar organisms will have similar traits.   C) Predicts evolutionary trends.

92. Five kingdoms of life: 1) Prokaryotae, 2) Protoctista, 3) Fungi, 4) Animalia, 5) Plantae

93. Hierarchy of classification: b) kingdom, phylum, class, order, family, genus, species.

94. D) Prokaryotae (prokaryotic cells have no nucleus, no organelles and naked DNA.

95. C) Protoctista

96. B) Fungi

97. The birthrate of this population will decrease within 20 years because there are so few people at the younger ages. As the middle-aged population ages & moves out of sexual activity, the youngsters aren't as numerous, so birth rate falls.

98. C) Tundra.......The rainfall is low (similar to a desert) with the coldest temperatures of the biomes we've studied. Vegetation is lichens, mosses and low shrubs.

99. C) Desert.........The rainfall is low (similar to the tundra) with moderate to hot temps. Cacti, shrubs and other plants that can quickly grow can be found there, or vegetation may be missing altogether.

100. B) Tropical Rainforest............... consists of numerous tall, broadleaf evergreen trees with several understory layers. Temps are fairly consistent (warm) throughout the year (25-50 degrees Celsius) with both rainy and dry seasons, the average monthly rainfall ranging from 60-300 mm.

101. A) Temperate Grasslands.......... consists of numerous grasses and herbs with average monthly temps from 5-30 degrees Celsius and average monthly rainfall from 50-150 mm.

102. B) Temperate Deciduous Forests .......... have numerous deciduous broadleaf trees with groundcover of herbs and mosses. The temperatures and rainfall are moderate and much less than the similar tropical rainforest.

103. D) Chaparral............ has numerous shrubs or bushes and low trees with moderate average monthly temps (10-20 degrees Celsius) and moderate rainfall per month (0-100 mm).

104. A) r-strategy....... Organisms with r-strategies grow and mature quickly, often without parental influence, and often reproducing once and then dieing (like salmon or many small insects (ants and bees).

105. B) k-strategy ............. Organisms with k-strategies grow and mature slowly, often get large in size, and often provide much parental care for their young, They often live to old ages and may reproduce many times over the years.

106. A) Unstable environments favor organisms with r-strategies. The environment changes quickly or often enough that the organism must grow quickly and reproduce quickly (typically once) before conditions become unfavorable.

107. B) Stable environments favor organisms with k-strategies. The environment stays relatively the same, so there is no hurry to grow and make babies. Instead, growth is slow, parents help the young to survive, and organisms grow to much larger sizes, allowing them to live for a long time and reproduce over many seasons.

108. Biomagnification is a process where chemical substances like DDT, diazinon or agent orange become more concentrated in the organisms of successively higher trophic levels. This often causes cancers or eventual death to the top carnivores when those chemicals become too concentrated in their tissues.