MB CH53 – Flashcards
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Which of these is characteristic of the photic zone of a freshwater biome?
-the presence of algae
-relatively cool water
-relatively stable water temperature
-dead organic matter
-low oxygen level
answer
-the presence of algae
"Photic" means light, and light encourages the growth of photosynthetic organisms.
question
The benthic zone of aquatic environments is defined as the _____.
-region that receives abundant sunlight
-region where phytoplankton are found
-region that receives little or no light
-substrate at the bottom of the body of water
-region that is flooded at high tide and not covered by water at low tide
answer
-substrate at the bottom of the body of water
This is the definition of the benthic zone.
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The _____ biome is the largest of Earth's biomes.
-marine
-desert
-grassland
-freshwater
-rain forest
answer
-marine
The marine biome is the largest of Earth's biomes
question
A(n) _____ is a region where fresh water and salt water mix.
-benthic zone
-intertidal zone
-aphotic zone
-estuary
-photic zone
answer
-estuary
Estuaries are regions where fresh water and salty marine water mix.
question
Aquatic biomes can be distinguished by chemical characteristics such as dissolved oxygen content and salinity and by physical characteristics such as water flow.
Which five of the following statements about aquatic biomes are true?
-All wetlands have soils that dry out periodically.
-Temperature drives water movement in some lakes.
-Estuaries are very productive and are used as breeding grounds by many species of fish.
-Tropical coral reefs generally exist in relatively shallow areas of the ocean.
-The lowest levels of dissolved oxygen in a stream are generally found in its turbulent headwaters.
-A freshwater organism permanently attached to the substrate would be unlikely to survive and reproduce in an estuary.
-Wetlands have slow water movement or no water movement and no turnover.
answer
-Temperature drives water movement in some lakes.
-Estuaries are very productive and are used as breeding grounds by many species of fish.
-Tropical coral reefs generally exist in relatively shallow areas of the ocean.
-A freshwater organism permanently attached to the substrate would be unlikely to survive and reproduce in an estuary.
-Wetlands have slow water movement or no water movement and no turnover.
Freshwater aquatic biomes include lakes, rivers, and wetlands with salinity less than 1%, whereas oceans are marine biomes, with an average salinity of 3.5%. The salinity of an estuary can range from less than 1% to over 3.5%, depending on river flow, tides, and proximity to the ocean. Of the freshwater biomes, streams are marked by their current, whereas lakes and wetlands are standing bodies of water.
question
Which of these species typically has a mortality rate that remains fairly constant over an individual's life span?
-grasses
-elephants
-oysters
-robins
-humans
answer
-robins
The mortality rate of robins remains relatively constant throughout their life span
question
Which of these organisms has a survivorship curve similar to that of humans?
-cats
-grasses
-oysters
-robins
-elephants
answer
-elephants
The mortality rate of elephants, like that of humans, remains relatively low for much of their life span and then dramatically increases for older individuals.
question
Look at the age-structure pyramids. The numbers between the bars (in the middle of the graphs) serve as the y-axis. What do these numbers represent?
-the number of people born in a particular year
-the age classes, in 5-year ranges
-the percentage of the population in each age class
-the population of males and females
-the total population, in millions
answer
-the age classes, in 5-year ranges
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What do the bars on the graphs represent?
-the number of males and females in each age group
-the number of males and females born in different years
-the percentage of males and females in each age group
-birth rate or death rate for each age group
answer
-the number of males and females in each age group
question
In 2010, how many 25- to 29-year-old women lived in Niger?
-about 0.5 million
-about 1.0 million
-about 1.2 million
-about 0.5 billion
-cannot be determined from the graph
answer
-about 0.5 million
question
The colors of the bars on the graphs indicate the life stage of the people in that age class. What does it mean if a bar is colored blue?
-The people in that age class are past reproductive age.
-The people in that age class are of reproductive age.
-The people in that age class have not yet reached reproductive age.
-The answer cannot be determined from the graphs.
answer
-The people in that age class are of reproductive age.
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The 2010 age-structure pyramid for Niger indicates that the population of Niger ________.
-was increasing
-was stable
-was decreasing
-cannot be determined from the graph
answer
-was increasing
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In Canada in 2010, which age classes contained the largest number of people?
-children between 5 and 14
-adults between 25 and 34
-adults between 35 and 45
-adults between 45 and 54
-adults between 55 and 64
answer
-adults between 45 and 54
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In Canada in 2010, people between the ages of 45 and 54 made up the largest percentage of the population. What factor is most likely to have caused this bulge in the age pyramid?
-the increased availability of oral contraceptives in the 1950s and 1960s
-an increase in the death rate during World War I and the influenza epidemic of 1917
-a decline in the birth rate during the Great Depression of the 1930s
-a surge in the birth rate after World War II ended in 1945
answer
-a surge in the birth rate after World War II ended in 1945
question
Assuming that current trends continue, predict how the age structure of Canada in 2030 will likely differ from that in 2010.
-The proportion of the population made up of children (ages 0-15) will increase.
-The proportion of the population made up of adults of reproductive age will increase.
-The proportion of the population made up of older adults (65+) will increase.
-The answer cannot be determined from the graph.
answer
-The proportion of the population made up of older adults (65+) will increase.
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Based on a comparison of the age-structure pyramids, which of the following would likely be a higher priority in Canada than in Niger?
-providing prenatal care
-building new schools
-providing childhood vaccinations
-providing long-term care for the elderly
answer
-providing long-term care for the elderly
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What do you observe about the relative timing of the peaks in lynx numbers and hare numbers?
-There is no relationship between when hare numbers peaked and when lynx numbers peaked.
-Lynx numbers typically peaked slightly before hare numbers.
-Hare numbers typically peaked slightly before lynx numbers.
-Hare numbers and lynx numbers typically peaked at the same time.
answer
-Hare numbers typically peaked slightly before lynx numbers.
question
What might explain the observation that hare numbers typically peaked slightly before lynx numbers?
-Both hare and lynx populations naturally go through regular cycles, and in this pair of populations, the hares peak slightly before the lynxes by chance.
-Both lynx and hare populations peak when weather is mild and food is plentiful, and both populations crash during severe weather.
-The lynx depend on the hares for food, but there is a delay between increased food availability and increased reproduction by the lynx.
-The peaks in the lynx population result in heavy predation of the hares, causing the hare population to crash soon after.
answer
-The lynx depend on the hares for food, but there is a delay between increased food availability and increased reproduction by the lynx.
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What does the right y-axis represent?
-resources, with quantity increasing from bottom to top
-resources, with quantity decreasing from bottom to top
-time, with duration increasing from left to right
-population, with size increasing from bottom to top
answer
-resources, with quantity decreasing from bottom to top
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What does the orange graph line represent?
-population size
-logistic growth
-exponential growth
-carrying capacity
answer
-logistic growth
question
Which of the following statements are true of logistic growth?
Select all that apply.
-When the population reaches carrying capacity, it stops growing.
-As the population approaches carrying capacity, it grows more rapidly.
-The population grows at a steady rate.
-As the population approaches carrying capacity, it grows more slowly.
answer
-When the population reaches carrying capacity, it stops growing.
-As the population approaches carrying capacity, it grows more slowly.
question
Which of the following statements are true of a population at carrying capacity?
Select all that apply.
-The population continues to grow at a constant rate.
-The population growth rate equals zero.
-The rate at which resources are used is equal to the rate at which they are supplied.
-The birth rate equals the death rate.
answer
-The population growth rate equals zero.
-The rate at which resources are used is equal to the rate at which they are supplied.
-The birth rate equals the death rate.
question
As a population approaches carrying capacity, environmental resistance __________.
-cannot be determined from the graph
-increases
-decreases
-remains constant
answer
-increases
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Which of the following factors does not contribute to environmental resistance?
-competition for space
-birth rate
-weather conditions
-environmental toxins
-competition for food
answer
-birth rate
question
Graphs A, B, and C represent three different patterns of population growth. Refer to these graphs as you read about the populations in the following questions.
A female darkling beetle laid her eggs in a sack of corn meal. The corn meal was an excellent source of food for the beetle larvae (mealworms), and the beetle population quickly increased. After four months, the beetles had eaten all of the corn meal, and the adult beetles flew away to find new food sources.
Which graph best represents the growth of the beetle population in the sack of corn meal?
answer
-Graph C
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Scientists grew a population of yeast cells in a flask to which they provided a constant supply of nutrients. As the population of yeast cells increased, competition for the nutrients also increased. This caused the population to grow more slowly, until the rate at which the yeast cells used the nutrients was equal to rate at which the nutrients were supplied to the flask.
Which of the three graphs shown in Part G best represents the growth of these yeast population?
answer
-Graph A
question
A pair of coyotes colonized a large island where rodents (their prey) were abundant. At first the number of coyotes increased. But as the coyote population increased, competition for prey also increased and the coyote population grew more slowly. In some years, weather conditions killed many of the rodents, causing some coyotes to starve. In other years, weather conditions were favorable for the rodent poulation, allowing the coyotes to thrive, reproduce, and raise many pups.
Which of the three graphs shown in Part G best represents the growth of this coyote population?
answer
-Graph B
