Ch. 5 Test; 11/12 – Flashcards
Unlock all answers in this set
Unlock answersquestion
list 4 characteristics that are used to describe a population
answer
geographic range, density and distribution, growth rate, and age structure
question
what natural factors can change a population's size?
answer
the natural factors that can change a populations size is the birthrate, death rate, and the rate at which an individual enters or leaves the population (immigration/emigration)
question
when do populations grow exponentially?
answer
populations grow exponentially when resources are unlimited
question
what is the characteristic shape of a logistic growth curve?
answer
the shape of a logistic growth curve has an S-shape
question
describe when logistic growth occurs
answer
it occurs when a population's growth slows and then stops, following a period of exponential growth
question
what is a limiting factor?
answer
a limiting factor is a factor that controls the growth of a population
question
how do limiting factors affect the growth of populations?
answer
limiting factors affect the growth of population by keeping most natural populations somewhere between extinction and overrunning the planet
question
list 3 density-dependent limiting factors
answer
predation, herbivory, parasitism, disease, stress from overcrowding
question
what is the relationship between competition and population size
answer
competition can have a massive impact on population because it can dec rease the size of some species and exponentially increase the size of some.
question
what is density-independent limiting factors?
answer
droughts, floods, wildfires, tornadoes, hurricanes
question
give 3 examples of density-independent factors that could severely limit the growth of a population of bats living in a cave
answer
could be a hurricane, a drought, or a dramatic increase/decrease in climate
question
what is population density
answer
refers to the number of individuals per unit area
question
what is age structure?
answer
the number of males and females of each age a population contains
question
what is geographic range?
answer
the area inhabited by a population is called its geographic range
question
what is a growth rate?
answer
a populations growth rate determines whether the size of the population increase, decreases, or stays the same
question
define exponential growth
answer
the larger a population gets, the faster it grows
question
what is logistic growth?
answer
it starts in exponential growth then plateaus because it has reached its carrying capacity which is dictated by limiting factors
question
when does logistic growth occur?
answer
it occurs under the conditions when a populations growth slows and then stops, following a period of exponential growth
question
what is carrying capacity?
answer
it is the maximum number of individuals of a particular species that a particular environment can support
question
population size can be limited by...
answer
competition, predation, parasitism and disease, unusual weather, and natural disaster
question
limiting factors determine the _________ ___________ of an environment for a species
answer
carrying capacity
question
what is a density-dependent limiting factors?
answer
it operates strongly only when the population is big/dense
question
competition is a _______-____________ limiting factor because the more individuals living in an area, the sooner they use up available resources
answer
density-dependent
question
what is a density-independent limiting factor?
answer
it affects all populations in a similar way, regardless of population size and density
question
what are examples of density-independent limiting factors?
answer
hurricanes, droughts, flooding (any type of natural disasters
question
the number of individuals of a single species per unit area is known as
answer
population density
question
the movement of individuals into an area is called
answer
immigration
question
the area inhabited by a population is known as its
answer
geographic range
question
when you're making a graph representing exponential growth you need what stuff
answer
title, x and y axis labels
question
the maximum number of organisms of a particular species that can be supported by an environment is called
answer
carrying capacity
question
describe the conditions under which logistic growth occurs
answer
logistic growth occurs under the conditions when a populations growth slows and then stops, following a period of exponential growth
question
what is carrying capacity? give an example
answer
carrying capacity is the maximum number of individuals of a particular species that a particular environment can support. an example of that would be like how many people could survive on a lifeboat after a shipwreck. Their survival depends on factors like how much food and water they have and includes competition as to who gets the amounts
question
how is the carrying capacity of a city's roads similar to the carrying capacity of an ecosystem
answer
both have a limit of space, and when reached carrying capacity on a road, movement stops. when reached carrying capacity in an ecosystem, population growth stops.
question
a limiting factor that depends on population size is called a
answer
density-dependent factor
question
one example of a density-independent limiting factor is
answer
hurricanes
question
how might increasing the amount of a limiting nutrient in a pond affect the carrying capacity of the pond?
answer
by increasing the amount of a limiting nutrient in a pond will affect the carrying capacity. I think it will do so because the carrying capacity number will get larger so more species can live there because the limiting factor is larger
question
what does "partitioning the resources" mean?
answer
everyone gets along and everyone gets even amount of resources (-/-)
question
describe the long-term effects of competition on populations of two different species competing for the same resources
answer
the long-term effects of competition on populations of two different species competing for the same resources would result on one of the populations dying out severely because the other population would get it
question
describe how a predator-prey relationship can control both the predator population and the prey population
answer
the predatory-prey relationship can control the predator population and the prey population because if the prey were to die out, the predator population would either die out, or have to start competing with another species for food. Furthermore, if the predator population decreased, the prey population would become heavily over-populated, resulted in the carrying capacity number to be reduced
question
how do parasites serve as a density-dependent limiting factor?
answer
parasites serve as a density dependent limiting factor beause the denser the host population is, the more easily parasites can spread from one host to another
question
what would happen to a population of predators if there was a sudden increase in food for the prey?
answer
if there were to be a sudden increase in food for the prey, the predator population would start to increase because there would be more prey for the predators to eat
question
what would a contagious virus that causes a fatal disease be considered a density-dependent limiting factor?
answer
a contagious virus that causes a fatal disease would be considered a density-dependent limiting factor because it relies on the population to be dense, and if the population were to be dense it would be easier for the contagious virus to spread to more and more species
question
how is the relationship between parasites and their hosts similar to a predator-prey relationship
answer
the relationship between parasites and their hosts is similar to a predator-prey relationship because the predator is a positive factor whereas the prey is the negative factor, and the same thing for parasite and hosts. The parasite is the positive factor and the host is the negative factor. The positive factor is getting what is needed without being harmed, and the negative factor is being weakened.
