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 typically factors that restrict population growth, such as limited space, food availability, and adverse weather conditions. These factors can lead to competition for resources and can ultimately limit the size of a population.
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 formula given states that the growth rate (g) is equal to the birth rate (b) minus the death rate (d). In this case, the birth rate is 760 and the death rate is 227. Therefore, the growth rate would be 760 - 227 = 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
The squirrel population decreased the most in 1999, as indicated by the graph.
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 population increased from 1994-1997 because during this time period, the number of squirrels in the population increased.
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
The correct answer is 200 squirrels. This is because the graph shows a decline in the number of squirrels over time, reaching its lowest point at a certain 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. This involves physically counting or surveying every individual in the population to determine its size. This method provides an accurate and precise measure of the population size.
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 does not involve directly counting the crabs themselves. Instead, it involves counting the number of holes made by the crabs, which can be used as an estimate of the population size. This method is used when it is difficult or impractical to directly observe and count individual organisms.
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
Based on the given information, we know that in a 1 square meter area there are 20 starfish. To estimate the population of starfish in the grouping, we can calculate the total number of square meters in the grouping by multiplying its length and width (10 meters x 5 meters = 50 square meters). Then, we can multiply this by the number of starfish in each square meter (50 square meters x 20 starfish = 1,000 starfish). Therefore, the estimated population of starfish in the grouping is 1,000.
9.
Check the conditions that can limit the growth of a population:
Correct Answer
A. Temperature and rainfall
Explanation
Temperature and rainfall are important factors that can limit the growth of a population. Both temperature and rainfall 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 be detrimental to the survival of many organisms, while inadequate or excessive rainfall can impact the availability of water and suitable habitats. Therefore, fluctuations in temperature and rainfall can significantly influence population dynamics and restrict population growth.
10.
What is the population density of the flamingos in the pond?
Correct Answer
A. 2.5 flamingoes per square meter
Explanation
The population density of the flamingos in the pond is 2.5 flamingoes per square meter. This means that there are 2.5 flamingoes on average for 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. Examples of producers include plants, algae, and some bacteria. They are essential for the food chain as they provide energy for other organisms, such as herbivores, which consume them.
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 portion of the population, releasing them back into the wild, and then recapturing a new sample later on to estimate the total population size. By comparing the number of marked individuals in the recaptured sample to the total sample size, scientists can make an estimate of 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 greater than the death rate, it means that more individuals are being born than are dying. This leads to a net increase in the 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 individuals that are marked, multiplied by the sum of the unmarked individuals and the recaptured individuals, divided by the number of individuals that are recaptured. This formula is used to estimate the size of a population based on the number of marked individuals that are recaptured in subsequent samples.
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 is a useful method for estimating a population when it is small or difficult to find. This means that the ecologist cannot directly observe or count the individuals in the population, so they rely on indirect evidence or signs of their presence. This could include looking for tracks, nests, or other indirect indicators of the population's existence. By using indirect observation, the ecologist can still gather information about the population size and characteristics without directly observing every individual.
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
The initial population of mice was 50. From this, 175 young mice were produced, resulting in a total of 225 mice (50 + 175 = 225). However, 159 mice died, so we need to subtract this number from the total population (225 - 159 = 66). Therefore, there would be a population of 66 mice remaining.
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 representative sample and then apply multiples of that area to the larger area. This allows for an estimation of the population size based on the observed sample, assuming that the larger area has a similar distribution of organisms. By using a sample, it is possible to gather data more efficiently and extrapolate it to the entire population.
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 time. It could be due to various factors such as high mortality rates, low birth rates, or migration out of the population. This decline in population can have significant implications for the ecosystem and the overall well-being of the species.
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 living in the same area and interacting with each other. In this case, a mouse, raccoon, and hawk are all different species, but they can be found living together in the same habitat and interacting with each other. 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
A limiting factor is something that restricts the growth or survival of a population. Time, in this context, is not considered a limiting factor because it does not directly affect the population's ability to grow or survive. In contrast, food and water, space, and weather can all have a direct impact on the population's ability to thrive.
21.
Population can change in size when:
Correct Answer
C. When new members join the population or when members leave the population
Explanation
The correct answer is when new members join the population or when members leave the population. This is because population size can change when individuals are added to or removed from a population. Birth rate equaling death rate or emigration rate equaling birth rate would not necessarily result in a change in population size, as these rates could balance each other out.
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 selecting a sample from the population and making inferences based on that sample. This approach takes into account the fact that it is often impractical or impossible to gather data from an entire population, so a smaller representative sample is used instead. By making reasonable assumptions and using statistical techniques, a sampling estimate can provide a close approximation of the true population parameter.
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 given area or ecosystem can sustainably support. It takes into account factors such as available resources, space, and environmental conditions. When the population exceeds the carrying capacity, there can be negative impacts such as resource depletion and increased competition for limited resources. Therefore, the correct answer is carrying capacity.
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. It is calculated by dividing the total number of individuals in the population by the total area of the habitat. Population density is an important ecological concept as it helps scientists understand the distribution and abundance of organisms in a given area, and how this may impact the interactions between species and the overall health of the ecosystem.
25.
When groups leave or are separated from their organism population to pursue a need, it is called:
Correct Answer
J. Emigration
Explanation
Emigration refers to the movement of individuals or groups out of a population. When groups leave or are separated from their organism population to pursue a need, it is considered as emigration.
26.
What is the one 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 make it difficult for organisms to find food and shelter. Additionally, snow can cover plants and inhibit their growth, which can lead to a decrease in food availability for animals. The harsh conditions of a snowstorm can also result in increased mortality rates, as organisms may not be able to withstand the cold or may become trapped and unable to escape. Overall, snow or a snowstorm can significantly impact the survival and reproductive success of a population, thereby limiting its growth.
27.
Which term matches these relationships:
A cape buffalo with an oxpecker (bird) on its back in Kenya. The oxpecker(bird) feeds from the supply of ticks on the buffalo, which in turn benefits from tick removal. This is called:
Correct Answer
G. Mutualism
Explanation
The relationship between the cape buffalo and the oxpecker is an example of mutualism. Mutualism is a type of symbiotic relationship where both species benefit from each other. In this case, the oxpecker benefits by feeding on the ticks on the buffalo's back, while the buffalo benefits from having the ticks removed. Both species rely on each other for survival and gain advantages from the relationship.
28.
Which term matches these relationships:
A deer tick attaches itself to a person walking in the woods. To access blood, the tick imbeds itself into the skin of the person. In the skin, the tick transfers bacteria that causes a rash and Lyme disease, which makes the person ill.
This is called:
Correct Answer
J. Parasite/parasitism
Explanation
The relationship described in the question is that of a tick attaching itself to a person and causing harm by transferring bacteria. This relationship is an example of parasitism, where one organism benefits (the tick) at the expense of the other organism (the person). The tick acts as a parasite by feeding on the person's blood and causing illness through the transmission of bacteria.
29.
If two species inhabit the same niche, one of the species will eventually die off as their is ____________ between organisms trying to survive with the same resources.
Correct Answer
L. Competition
Explanation
If two species inhabit the same niche, they will compete with each other for the same resources. This competition can include competition for food, shelter, mates, or any other resources necessary for survival. Eventually, one of the species will be more successful in obtaining these resources and outcompete the other species, leading to the extinction of the less successful species. This process is known as competition, which plays a significant role in natural selection and the survival of species.
30.
Over time the characteristics that have helped individuals survive are inherited by their offspring. These are:
Correct Answer
D. Adaptations
Explanation
Adaptations refer to the traits or characteristics that individuals develop over time in order to survive and reproduce in their environment. These adaptations can be physical, behavioral, or physiological and are passed on to future generations through inheritance. By possessing advantageous adaptations, individuals have a higher chance of survival and reproductive success, leading to the perpetuation of these traits in the population over time. This process is known as natural selection, where individuals with beneficial adaptations are more likely to survive and pass on their genes to the next generation.
31.
Which term matches these relationships:
Remora are long, slender brown fish with a dorsal fin used as an oval sucker-like structures that open and close to take a firm hold on the larger marine animals, like a shark. By sliding backward, the remora can increase the suction, or it can release itself by swimming forward. Remora's are commonly found attached to sharks,using them as transport and protection and also obtaining food from fragments dropped by them.
This is called:
Correct Answer
I. Commensalism
Explanation
The relationship described in the passage is commensalism. Commensalism is a type of symbiotic relationship where one organism benefits while the other is neither harmed nor benefited. In this case, the remora benefits by using the shark as transportation, protection, and a source of food, while the shark is unaffected by the presence of the remora.
32.
The characteristic of an individual that makes it better suited for its environment:
Correct Answer
A. Natural selection
Explanation
Natural selection is the process by which certain traits or characteristics become more common in a population over time because they provide a survival or reproductive advantage. This means that individuals with these advantageous traits are more likely to survive and reproduce, passing on their genes to future generations. As a result, the population becomes better suited to its environment as these beneficial traits become more prevalent. Therefore, natural selection is the characteristic that makes an individual better suited for its environment.
33.
The organism that benefits from living in or on another:
Correct Answer
J. Parasite/parasitism
Explanation
Parasite/parasitism refers to the relationship where one organism, the parasite, benefits from living in or on another organism, the host, at the expense of the host. The parasite obtains nourishment and shelter from the host, while the host is harmed in the process. This relationship is a form of symbiosis, where two organisms live in close association, but unlike mutualism where both organisms benefit, in parasitism, only the parasite benefits. This relationship is a result of adaptations that allow the parasite to exploit the resources of the host and can be a result of natural selection.
34.
The organism that is caused harm as other organism lives in or on it:
Correct Answer
J. Host
Explanation
A host is an organism that is harmed by another organism that lives in or on it. This relationship is known as parasitism, where the parasite benefits at the expense of the host. The parasite relies on the host for resources and shelter, while causing harm or damage to the host's health or well-being. The host is unable to get rid of the parasite and is negatively impacted by its presence.
35.
The relationship between two species that benefits at least one of the species:
Correct Answer
F. Symbiosis
Explanation
Symbiosis is the correct answer because it refers to a relationship between two different species where at least one of the species benefits. In symbiotic relationships, the species involved may rely on each other for survival, reproduction, or other important aspects of their lives. This can include mutualistic relationships where both species benefit, commensalism where one species benefits and the other is unaffected, or parasitism where one species benefits at the expense of the other.
36.
The relationship that benefits both species:
Correct Answer
L. Mutualism
Explanation
Mutualism refers to a relationship between two species in which both benefit from each other. This can involve cooperation in finding food, protection, or other resources. In mutualism, both species have evolved to depend on each other for survival and reproduction. This relationship is characterized by a mutual exchange of benefits, where both species gain an advantage.
37.
The role of an organism in its habitat:
Correct Answer
A. Niche
38.
Which of these relationships is the best example of parasitism?
Correct Answer
C. A flea living on cat blood
Explanation
A flea living on cat blood is the best example of parasitism. In this relationship, the flea benefits by feeding on the cat's blood, while the cat is harmed as it loses blood and may experience discomfort or health issues due to the flea's presence. This demonstrates the characteristic of parasitism, where one organism (the parasite) benefits at the expense of another organism (the host).