1.
All of the following are examples of limiting factors for populations except:
Correct Answer
C. Emigration
Explanation
Emigration is not a limiting factor for populations because it refers to individuals leaving a population, which can actually help alleviate population pressure. Limiting factors are factors that restrict the growth of a population, such as limited space or food availability. Weather can also be a limiting factor as extreme conditions can affect the survival and reproduction of individuals.
2.
Ecologists use the birth and death rates to calculate a population's growth rate, the rate the population is changing. The birth rate (b) minus the death rate (d) equals the growth rate (g). So, B-D=G
Based on this formula: a population of rabbits with an average of 760 births and 227 deaths has a growth rate of _________ per year:
Correct Answer
A. 533 rabbits
Explanation
The birth rate is given as 760 and the death rate is given as 227. To calculate the growth rate, we subtract the death rate from the birth rate: 760 - 227 = 533. Therefore, the growth rate of the population of rabbits is 533 rabbits per year.
3.
Use the graph to answer the questions about the changes in squirrel population.
Which year did the squirrel population decrease the most?
Correct Answer
C. 1999
Explanation
Based on the graph, the squirrel population is shown to decrease the most in the year 1999. The population sharply drops from the previous year and remains lower than the other years in the graph. This significant decrease suggests that something may have happened in 1999 that caused a decline in the squirrel population.
4.
Use the graph to answer the question about changes in the squirrel population.
Over which time period(s) did the population increase?
Correct Answer
A. From 1994-1997
Explanation
The graph shows an upward trend in the squirrel population from 1994 to 1997. During this time period, the number of squirrels increased consistently.
5.
Use the graph to answer the changes in squirrel population questions.
What was the size of the population the year the number of squirrels reached its lowest point?
Correct Answer
A. 200 squirrels
Explanation
Based on the graph, the number of squirrels reaches its lowest point in a particular year. At this point, the population size is 200 squirrels.
6.
Counting all the members of a ___________ is a method of __________________.
Correct Answer
A. Population and direct observation
Explanation
Counting all the members of a population is a method of directly observing the population. By physically counting each individual, we can obtain an accurate count of the population size. This method is reliable and provides a direct measurement of the population without any estimation or inference.
7.
Counting fiddler crab holes on the tidal flats on an island is a _____________________ method of determining fiddler crabs populations.
Correct Answer
E. Indirect observation
Explanation
Counting fiddler crab holes on the tidal flats on an island is an indirect observation method of determining fiddler crab populations because it involves inferring the population size based on the presence of their burrows rather than directly counting the individual crabs.
8.
An starfish grouping is 10 meters long and 5 meters wide. In a 1 square meter area you count 20 starfish.
Estimate the population of starfish in the grouping.
Correct Answer
C. 1,000
Explanation
If there are 20 starfish in a 1 square meter area, then in a 10 meter long and 5 meter wide grouping, there would be a total of 10 x 5 = 50 square meters. Therefore, the estimated population of starfish in the grouping would be 50 x 20 = 1,000 starfish.
9.
Check the conditions that can limit the growth of a population:
Correct Answer
A. Temperature and rainfall
Explanation
Temperature and rainfall are two important factors that can limit the growth of a population. Both temperature and rainfall directly affect the availability of resources such as food and water, which are essential for the survival and reproduction of individuals within a population. Extreme temperatures can lead to physiological stress and reduce reproductive success, while insufficient rainfall can result in water scarcity and limited food availability. Therefore, populations may struggle to grow and thrive in areas with unfavorable temperature and rainfall conditions.
10.
What is the population density of the flamingos in the pond?
Correct Answer
A. 2.5 flamingoes per square meter
Explanation
The correct answer is 2.5 flamingoes per square meter. This means that there are 2.5 flamingoes on average occupying every square meter of the pond.
11.
What is a producer?
Correct Answer
A. An organism that makes its own food energy.
Explanation
A producer is an organism that is able to produce its own food energy through the process of photosynthesis or chemosynthesis. This means that it can convert sunlight or inorganic compounds into organic compounds, such as glucose, which can be used as a source of energy. Producers are typically plants or algae, and they form the base of the food chain by providing energy to other organisms through consumption or decomposition.
12.
Identify this method of estimating populations:
Red wolves are tagged, released and checked systematically.
Correct Answer
L. Mark and recapture
Explanation
The method described in the question, where red wolves are tagged, released, and checked systematically, is known as mark and recapture. This method involves marking a sample of individuals, releasing them back into the population, and then recapturing a second sample at a later time. By comparing the number of marked individuals in the second sample to the total number of individuals in the sample, scientists can estimate the population size.
13.
In general, which is a true statement about population size:
Correct Answer
C. If birth rate > death rate, population size increases
Explanation
If the birth rate is higher than the death rate, it means that more individuals are being born into the population than are dying. This leads to a net increase in population size over time.
14.
What does the basic formula for mark and recapture mean?
Correct Answer
A. The population sample equals the number marked multiplied by the sum of the unmarked and recaptured divided by the number recaptured
Explanation
The basic formula for mark and recapture means that the population sample is equal to the number of marked individuals multiplied by the sum of the unmarked and recaptured individuals, divided by the number of recaptured individuals. This formula is used to estimate the size of a population by marking a certain number of individuals, releasing them back into the population, and then recapturing a portion of the population at a later time. By using this formula, scientists can estimate the total population size based on the proportion of marked individuals in the recaptured sample.
15.
When might an ecologist use indirect observation to estimate a population?
Correct Answer
A. Indirect observation may be used when a population is small or difficult to find.
Explanation
Indirect observation can be used when a population is small or difficult to find because it allows the ecologist to gather information about the population without directly observing or interacting with the individuals. This method can be particularly useful when the population is elusive, secretive, or located in inaccessible areas. By using indirect evidence such as tracks, nests, or signs of activity, the ecologist can estimate the population size or study its behavior without disturbing or influencing the organisms. Additionally, indirect observation can be a practical and efficient way to gather data when direct observation is not feasible or would be impractical.
16.
Suppose a population of 50 mice has produced 175 young.
If 159 mice died, how many mice are now in the population?
(Assume for this question that no mice have moved into or out of the population for other reasons).
Correct Answer
A. There would be a population of 66 mice.
Explanation
If there were originally 50 mice and they produced 175 young, the total number of mice would be 50 + 175 = 225. However, if 159 mice died, the current population would be 225 - 159 = 66 mice.
17.
One method of estimating population size is to count the number of organisms in a small area _________ and then apply multiples of that area to the larger area.
Correct Answer
P. Sample
Explanation
One method of estimating population size is to count the number of organisms in a small area as a sample and then apply multiples of that area to the larger area. This allows for extrapolation and estimation of the population size in the larger area based on the observed sample.
18.
What does a negative growth rate mean?
Correct Answer
A. The population is declining.
Explanation
A negative growth rate means that the population is declining. This indicates that the number of individuals in the population is decreasing over a specific period of time. It could be due to factors such as death rate exceeding birth rate, emigration, or other reasons causing a decrease in population size.
19.
A mouse, raccoon and hawk are all members of the same:
Correct Answer
C. Community
Explanation
A community refers to a group of different species that live and interact in the same area. In this case, the mouse, raccoon, and hawk are all different species that coexist and interact with each other in their shared environment. Therefore, they are all members of the same community.
20.
All of the following are examples of limiting factors except:
Correct Answer
A. Time
Explanation
Limiting factors are factors that restrict the growth or survival of a population. They can include things like availability of food, water, and space, as well as the effects of weather conditions. However, time is not typically considered a limiting factor as it is a constant and does not directly restrict population growth or survival.
21.
Population can change in size when:
Correct Answer
C. When new members join the population or when members leave the population
Explanation
Population can change in size when new members join the population or when members leave the population. This is because the addition of new individuals or the removal of existing individuals affects the overall population count. The other options mentioned in the question, such as the birth rate equaling the death rate or the emigration rate equaling the birth rate, do not necessarily result in a change in population size as they only balance the population dynamics without causing any net increase or decrease in the total number of individuals.
22.
What is a sampling estimate?
Correct Answer
A. A sampling estimate is an approximation of a number based on reasonable assumptions.
Explanation
A sampling estimate is an approximation of a number based on reasonable assumptions. It is a method used to estimate a population parameter by taking a sample from the population and using statistical techniques to infer information about the entire population. This approach is commonly used when it is not feasible or practical to count or measure every individual in the population. By making reasonable assumptions about the sample and using statistical methods, a sampling estimate can provide a reliable approximation of the population parameter of interest.
23.
The largest population that an area can support is called:
Correct Answer
H. Carrying capacity
Explanation
Carrying capacity refers to the maximum population size that a particular environment can sustain indefinitely. It is determined by factors such as the availability of resources like food, water, and space, as well as the effects of limiting factors such as competition, predation, and disease. When a population exceeds the carrying capacity of its environment, it may experience a decline in resources and an increase in mortality, leading to a decrease in population size. Therefore, the term "carrying capacity" accurately describes the largest population that an area can support.
24.
The number of individuals in an area of a specific size:
Correct Answer
G. Population density
Explanation
Population density refers to the number of individuals in a specific area of a given size. It is a measure of how crowded or dispersed a population is within a particular habitat or ecosystem. Population density is calculated by dividing the total number of individuals in a population by the total area they occupy. This measure helps scientists understand the distribution and abundance of a species, as well as its interactions with the environment and other species.
25.
When groups leave or are separated from their organism population to pursue a need, it is called:
Correct Answer
J. Emigration
Explanation
When groups leave or are separated from their organism population to pursue a need, it is called emigration. Emigration refers to the movement of individuals or groups out of a population or area. In this context, it specifically refers to the movement of groups leaving their population to fulfill a certain need.
26.
From the list below, identify the weather condition that can limit the growth of a population?
Correct Answer
A. Snow or a snowstorm.
Explanation
Snow or a snowstorm can limit the growth of a population because it can cause extreme cold temperatures and cover the ground with thick layers of snow. This can make it difficult for animals to find food and water, and can also lead to the destruction of habitats and shelter. Additionally, snowstorms can cause transportation disruptions and power outages, which can further impact the survival and reproduction of a population.