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Unit 3

Terms in this set (57)

Scientists are closely monitoring caribou populations to examine the effect of global climate change on habitat. The maximum population size for a herd of caribou based on the habitat was 500,000. A herd of caribou currently has a population size of 198,000 caribou as a result of habitat loss. Which of the following methods should be used to determine the percent change between the maximum population and the current population for the herd of caribous?
(198,000 caribou - 500,000 caribou)/500,000 caribou x 100
What is an environmental factor that would cause an increase in animal population?
Increased availability of food
r-selected species
Species that reproduce early in their life span and produce large numbers of usually small and short-lived offspring in a short period. --rats -- Type 3
K-selected species
Species that produce a few, often fairly large offspring but invest a great deal of time and energy to ensure that most of those offspring reach reproductive age. --humans and elephants -- Type 1 and Type 2
The many finch species of the Galápagos Islands evolved from a single species that immigrated to the islands from the coast of South America. These species differ primarily in beak shape, which is closely related to the type of food each species specializes in eating.
Which of the following best explains why each of the finch species on the Galápagos Islands evolved to be specialists?
Islands have limited food resources, forcing species to feed on a small range of food items
Demographic Transition Model
Stage 1=Low growth, Stage 2=High Growth, Stage 3=Moderate Growth, and Stage 4=Low Growth. A country moves from high birth and death rates to low birth and death rates through time.
1 and 2: birth rates are high and the population is growing rapidly
3: birth rates start to decline, death rates are already low, and the population is still growing, though not as rapidly as in the earlier stages.
4: birth and death rates are low and the population size stabilizes
5: declining popualtion
What is a density-independent factor that controls population size?
Occurrence of droughts and flooding
Human population growth in 2018 was 1.07%. If this growth rate remains constant, in what year will the human population double?
2083
r-selected are most likely to be a
invasive species --> have very large numbers of offspring and can quickly colonize a new area as a result of being able to outcompete other species
What is the best prediction for how long it will take for the population to double if growth rate of the world is 1.09%?
Number of years = 70/1.09
What can be interpreted from an age-structure diagram?
The relative population growth of the population
Growth rate equation
growth rate = birth rate - death rate
Percent change equation
new-old/old x 100
Hares are the prey for the lynx. The lynx is a little bit larger than the bobcat. Scientists plan to investigate the size of the lynx and hare populations over a 3 year period. What is a good hypothesis?
An increase in the lynx population will cause a decrease in the hare population.
Venus fly traps grow best in nutrient-poor, acidic soil. They typically grow in longleaf pine savanna ecosystems in the Carolinas. What describes the species?
A specialist species, because it only thrives in soil with a low pH and nutrient levels
Orchid mantis are highly camouflaged when standing on certain species of orchids. Tropical coachroaches can live anywhere it can find water and food. Why would the orchid mantis be more affected than the tropical coachroach by climate change?
Orchid mantises are advantaged in habitats that remain constant; the rain forest shifts beach of climate change globally
Salamanders lay eggs in small freshwater pools and feeds on insects; Osprey habitats include rivers, bays, and swamps and the birds feed on animals in the water or on land; Snapping turtles live in fresh or brackish water and feed on plants, fish, frogs, snakes; Beavers build lodges, pond banks, and lake shores and eat many shrubs, grasses, and crops --> which is a specialist?
Salamanders
Population momentum
Continued population growth after fertility drops to replacement level
How does total fertility of society change as a country goes through the demographic transition model (dtm)?
It decreases
Replacement level fertility
Is greater in countries that have high infant-mortality rates than it is in countries with low infant-mortality
Birth rates drop in the dtm because
more women enter the workforce in developing nations
2 factors that indicate the quality of life include
life expectancy and infant mortality rate
Country population has a population of 100 million and an annual growth rate of 3.5%, growth rate is constant, what will the population of the country be in 40 years?
400 million
The greatest rate of population growth happens in what stage of the dtm?
Transitional
US fertility rate is declining and is under the replacement level; how is the population still growing?
Immigration
As progressing through dtm, what decreases first?
Death rate
Why are there high death rate in phase 1?
Infant and childhood mortality
What is associated with the transition from rural to urban?
Reduced birth rates
Carrying capacity
Largest number of individuals of a population that a environment can support
Overshoot
When a population becomes larger than the environment's carrying capacity (too much competition for resources)
Which dtm indicates population stability?
Column-shaped diagram
Which of the following best describes the trends seen in the total fertility rates for the world population from 1950 to the projected rates in 2040 ?
Total fertility rates declined rapidly from 1960 to 2000 because women had children later in life as a result of increased educational opportunities.
Replacement level fertility
2.1
A scientist is studying a biome that experiences large seasonal fluctuations in both temperature and precipitation patterns. Would generalists or specialists be better?
Generalists would be most abundant, because the resources available would be constantly changing.
Which of the following best describes a difference between generalist species and specialist species?
Generalists use a large range of resources, while specialists have a limited range of resources they use to survive.
A variety of plants and animals inhabit a forest ecosystem. Which statement correctly explains why certain organisms would be more likely to survive than others if a forest fire burned the area?
Generalist species are more likely to survive because they can thrive in a wide variety of environmental conditions and can make use of a variety of different resources.
r-selected are generally
generalists
K-selected are generally
specialists
What is something that moves a country to a higher stage in dtm?
Improvements in health-care services and medical research
Type 3 characteristic
The organism produces large numbers of offspring every time it reproduces.
Type 2 characteristic
Away from the colony, bees experience a constant probability of death per unit time as a foraging species.
Exceeded the carrying capacity of the island leads to?
Extreme resource depletion.
Based on current trends and patterns, which of the following statements best predicts how the human population will change over the next 50 years?
As the population density increases, there will be an increase in disease transmission, leading to increased mortality.
The rule of 70 can be used to determine a population's doubling time. Doubling time is a measure of the
Population growth rate
Which of the following density-independent factors can affect the size of a human population?
Heat waves
Which of the following statements best describes why birth and death rates are changing in a country that is in Phase 2 of the demographic transition?
Individuals have better sanitation and access to clean drinking water.
A country is currently in the second stage of the demographic transition. Currently the country has a birth rate of 37.9 births per 1,000 individuals and a death rate of 13.4 deaths per 1,000 individuals.; Which of the following changes would indicate that the country is moving from the second stage into the third stage of the demographic transition?
The birth rate declines to 25.3 births per 1,000 individuals.
The demographic transition model describes population change over time as a country becomes more developed. Age-structure diagrams describe how populations are distributed across age ranges. Which of the following age-structure diagrams best displays the age ranges in a country that is in stage 2 of the demographic transition?
An expansive pyramid age-structure diagram
r-selected vs K-selected species graph
*could not add on* --> r is a curve up above carrying capacity; K is a large increase then steady decrease, increase, decrease trying to maintain carrying capacity
Raccoons eat a variety of foods and can live in a variety of habitats, including locations near humans. Tiger salamanders eat an abundance of worms and insects and require wetland habitats so they do not dry out. Which of the following best identifies the two different species?
Raccoons are generalists, and salamanders are specialists.
Stage 1 has a _____ fertility rate?
high
Why does total fertility rate decrease?
The total fertility rate decreased as a result of a delay in age of first marriage and increased contraceptive use.
A country has a birth rate of 351,000351,000 individuals and a death rate of 131,000131,000 individuals. The death rate was 371,000371,000 individuals in 1950, 281,000281,000 individuals in 1970, and 211,000211,000 individuals in 1990. Which of the following statements best explains why the country has a declining death rate?
The country is in stage 2 of the demographic transition, and life expectancy has increased because of improvements in public health, sanitation, and access to food.
In a certain country, the birth rate is high, the death rate is high, and there are many children that are part of the workforce. The country is most likely in which of the following stages of the demographic transition?
Stage 1
The supply of Earth's fresh water is fixed and is being depleted at a rapid rate. Which of the following best describes the effects of a limited freshwater supply on human populations?
World food production will decrease, leading to increased famine. --> Stressed water supplies will negatively affect agriculture as availability of clean fresh water decreases, and food shortages will be more prevalent.
Which of the following best describes the change in the carrying capacity of the human population if growth is limited by conditions set forth by the Malthusian theory?
The carrying capacity will decrease, and the human population size will experience a dieback.
In 1950, a country had a total fertility rate of 5.9. In 2010, the total fertility rate of the country was 2.3. Which of the following is most likely the reason for the change in total fertility rate?
Women had increased educational opportunities and had children later in life.
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