Ecology Flashcards
(37 cards)
An ecologist conducts a study to answer the question: Are predator-prey interactions more important intropical forests than in temperate forests? At what level is the ecologist working?
(a) Landscape
(b) Ecosystem
(c) Community
(d) Population
(e) Organismal
c) Community
An ecologist wants to answer the question: Have tiger sharks been declining in the north Atlantic? At what level is the ecologist working?
(a) Landscape
(b) Ecosystem
(c) Community
(d) Population
(e) Organismal
(d) Population
The tropics are warmer than more northern or southern latitudes because
(a) The tropics have more hours of sunlight on a year-round basis
(b) Sunlight strikes the tropics at a more direct angle
(c) The tropics are better able to absorb the sun’s radiation
(d) The maritime effect is greater in the tropics
(b) Sunlight strikes the tropics at a more direct angle
The tropics receive a lot of precipitation because
(a) Rising warm air cools and releases moisture
(b) The rising warm air carries the moisture north and south
(c) Most of the tropics are close to warm oceans
(d) Mountains cause moisture to be released from the air
(a) Rising warm air cools and releases moisture
Which is an example of how ocean currents influence land temperatures? (textbook)
(a) The California current warms the western USA
(b) The Labrador current cools eastern Canada
(c) The Antarctic Circumpolar Current warms the southern tips of Africa and South America
(d) Western coasts of continents tend to be warmed by the major subtropical gyres while eastern coasts
tend to be cooled
(b) The Labrador current cools eastern Canada
Deserts tend to occur
(a) on the windward side of mountains
(b) near the equator
(c) near continental coasts
(d) at about 300 latitude north and south
(d) at about 300 latitude north and south
Which of the following best describes a link between climate and terrestrial biomes?
(a) Forested biomes are usually found in the tropics because it is warmer there
(b) Non-forested biomes are more common where the climate is drier
(c) Differences in climate matter more in biomes close to the equator
(d) Tropical rainforests occur in cooler climates than subtropical deserts
(b) Non-forested biomes are more common where the climate is drier
Temperate broadleaf forests
(a) tend to be drier than northern coniferous forests
(b) tend to be warmer than northern coniferous forests
(c) tend to be cooler than temperate grassland
(d) tend to be drier than temperate grassland
(b) tend to be warmer than northern coniferous forests
The tundra is found in a band across the Northern Hemisphere, especially along the Arctic Ocean. Why is
there no comparable band of tundra in the Southern Hemisphere?
(a) Tundra plants and animal haven’t been able to migrate that far
(b) It is warmer at similar latitudes in the Southern Hemisphere
(c) Global wind and pressure areas differ in the Northern and Southern Hemispheres
(d) There isn’t much land at those latitudes in the Southern Hemisphere
(d) There isn’t much land at those latitudes in the Southern Hemisphere
Why can tundra also be found in the tropics?
(a) High elevation areas in the tropics have a climate similar to the Arctic
(b) Migrating birds transport seeds from tundra plants from the poles to the equator
(c) The tundra biome has evolved twice
(d) Globally, air moves from the poles to the equator
(a) High elevation areas in the tropics have a climate similar to the Arctic
Which of the following terrestrial biomes is subject to frequent fires?
(a) savanna
(b) temperate forest
(c) tropical forest
(d) desert
(a) savanna
Which is a correct ordering of biomes from high to low mean annual precipitation?
(a) savannah, desert, temperate grassland
(b) broadleaf forest, tropical rainforest, tundra
(c) savannah, broadleaf forest, temperate grassland
(d) desert, tundra, temperate grassland
(e) tropical rainforest, savannah, desert
(e) tropical rainforest, savannah, desert
Which of the following characteristics best distinguishes temperate grassland from tropical savannah?
(a) mean annual temperature
(b) mean annual precipitation
(c) maximum annual precipitation
(d) importance of disturbance
(a) mean annual temperature
Which of the following is NOT a characteristic of most populations?
(a) Individuals belong to the same species
(b) Individuals live in the same place
(c) Individuals are all roughly the same age
(d) Individuals are likely to interact with each other
(c) Individuals are all roughly the same age
Which of the following describes the density of a population?
(a) Approximately 2000 grizzly bears live in Banff National Park
(b) There are 150 bighorn sheep for every cougar in Jasper National Park
(c) The number of pikas in Kluane National Park has declined by 20% over 3 years
(d) On average, there are five elk per square kilometre in the Ghost Wilderness Area
(d) On average, there are five elk per square kilometre in the Ghost Wilderness Area
A biologist reported that a sample of ocean water had 5 million diatoms of the species Coscinodiscus
centralis per cubic meter. What was the biologist measuring?
(a) density
(b) dispersion
(c) carrying capacity
(d) quadrats
(e) range
(a) density
Alder trees tend to be found beside streams and rivers. Within a forest, the dispersion pattern of alder is most likely to be (a) dense (b) clumped (c) random (d) uniform
(b) clumped
How would the dispersion of humans in Canada best be described?
(a) dense
(b) clumped
(c) random
(d) uniform
(b) clumped
The mark-recapture method would likely be most useful for estimating densities of (textbook) (a) phytoplankton (b) annual plants (c) perennial plants (d) snowshoe hares
(d) snowshoe hares
An ecologist wanted to determine the size of a population of lemmings on an island in northern Canada. He set 200 traps and caught 30 lemmings. He marked each with an ear tag and released them. A week later he reset the traps and caught 40 lemmings, 5 of which had tags. What would be his best estimate of the total number of lemmings in the population? (textbook) (a) 150 (b) 200 (c) 240 (d) 600 (e) 1200
N = sn/x s = 30 n = 40 x = 5 N = (30 x 40)/5 = 240
(c) 240
A marine ecologist wanted to determine the size of a population of green crabs that had invaded a coastal bay. She swam 10 transects across the bay, looking for green crabs. She found 50 and marked each with a notch on its back and then released it. Three days later she swam 10 transects again. This time she saw 80 crabs but only 2 had marks. What would be her best estimate of the total number of green crabs in the population? (textbook) (a) 100 (b) 160 (c) 400 (d) 2000 (e) 4000
N = sn/x s = 50 n = 80 x = 2 N = (50 x 80)/2 = 2000
(d) 2000
Populations are most likely to exhibit exponential growth
(a) under crowded conditions
(b) if the population growth rate (r) is very high
(c) as population size (N) increases
(d) if resources are not limiting
(e) if body size is small
(d) if resources are not limiting
Per capita birth rate was 0.25 and per capita death rate was 0.15 for a population of 1000 protozoa in
a laboratory flask. What is the per capita growth rate of the population?
(a) 250
(b) 150
(c) 100
(d) 0.10
(e) 0.40
r = b – d r = 0.25 – 0.15 = 0.10
(d) 0.10
Twenty rats were introduced onto an island. Per capita birth rate was estimated to be 2.5 and per
capita mortality rate at 0.4. If the population grew exponentially, approximately how many rats were
present on the island after 5 generations? (requires calculator)
(a) 42
(b) 20,000
(c) 70,000
(d) 500,000
(e) more than 700,000
Nt = N0ert N0 = 20 e = 2.817 r = b-d = 2.5 – 0.4 = 2.1 t = 5 Nt = 20 x e^(2.1x5) = 1,056,311 rats
(e) more than 700,000
