Study Island: Organism Interactions and Population Dynamics
According the information shown in the graph (line levels right before 100), what is the carrying capacity for Eastern Cottontail Rabbits in Red Forest?
100
If the human population continues to change at the same rate, what will the population most likely be by the year 2050?
12 billion
In January, a small number of Eastern Cottontail Rabbits were introduced into Red Forest. The population curve of the rabbits is shown below. The population of the rabbits increased rapidly at first, then leveled off in late March. Which of the following is the most likely explanation for why the population of Eastern Cottontail Rabbits did not continue to increase rapidly?
As the population of Eastern Cottontail Rabbits in Red Forest increased, food resources became scarce.
Influenza is an infectious disease caused by an RNA virus. In humans, the disease can cause fever, sore throat, muscle pains, respiratory problems, and, in severe cases, death. Influenza-associated deaths are most common in children, adults age 65 or older, and people with weakened immune systems. The graph below shows the number of influenza-associated pediatric deaths that occurred in the United States from 2008 to early 2012.
Diseases can disrupt the balance of human populations by temporarily increasing the death rate.
Which graph shows a population in which the death rate consistently exceeds the birth rate?
Graph gradually going down
Ants release chemical pheromones that are detected by other ants. Which of the following best describes the purpose of this?
It is a means of communication.
To reduce the number of rabbits in a population, a disease was introduced. Which of these best explains how this would reduce the population of rabbits?
It would increase the death rate.
_______ can be defined as a long-term relationship between individuals of different biological species that typically results in a benefit for at least one of the individuals.
Symbiosis
Honeybees need the nectar of flowering plants in order to produce honey. How can a honeybee's relationship with flowering plants be considered mutualism?
The bees help pollinate the plants.
A bird species is introduced in an area. The bird species feeds on the same seeds as the bird species that already occupied the area. What is the most likely effect on the original bird species?
The population of the original bird species will decrease.
Which of the following is an example of parasitism? -a tapeworm lives in the intestine of a cat and absorbs nutrients for energy -a pack of gray wolves hunts, kills, and consumes a white-tailed deer for energy -a field mouse and a rabbit compete for resources in a field ecosystem -a bird builds a nest and lays eggs in the branches of an oak tree
a tapeworm lives in the intestine of a cat and absorbs nutrients for energy
In any ecosystem, the basic resources that organisms need for survival are always in limited supply. Which of the following is a potential result of these limitations? -competition among members of an ecosystem for resources -unlimited population growth of certain species in an ecosystem -elimination of one or more species from an ecosystem
competition among members of an ecosystem for resources and elimination of one or more species from an ecosystem
Male birds of paradise are known to sometimes dance and throw feathers over their body when females are present. This behavior is the bird of paradise's method of _______.
courtship
For one week, Jacob observed the behavior of a particular male bird near his home. During this time, he noticed that the bird spent its time engaging in several different activities. Which of the activities that Jacob observed is a social behavior? -fighting off rival males -flying with other birds in a formation -producing different songs and calls -grooming its feathers
fighting off rival males, flying with other birds in a formation, and producing different songs and calls
graph that is mostly flat and then gets bigger really quickly
positive exponential growth
If the birth rate exceeds the death rate...
the population grows
Sometimes a bee will perform a maneuver, known as the "waggle dance," in front of another bee. What is the purpose of this maneuver?
to help bees cooperate
Graph shows species 1 and 2 doing the opposite of each other What can be said about the relationship between species 1 and species 2?
When the population of species 1 increases, the population of species 2 decreases.
White-tailed deer are considered to be an overpopulated species in the central United States. Which of these events probably contributed the most to white-tailed deer exceeding their carrying capacity?
a decrease in natural predation of white-tailed deer
The human population has increased dramatically over the last 200 years. Currently, there are almost 7 billion humans on Earth. Which of the following factors have contributed the most to the rapid growth of the human population? -advances in manufacturing and robotic technologies -advances in food production and medical technologies -advances in printing and metalworking technologies -advances in transportation and communication technologies
advances in food production and medical technologies
What is the term that describes the size of a population that can be supported by a given ecosystem?
carrying capacity
A farmer plants two species of grass with similar nutrient needs on the same small plot of land. What kind of interaction will most likely occur between the two species?
competition
All animals exhibit some form of social behavior. Which of the following types of behavior is best classified as a form of social behavior? -predatory behavior -foraging behavior -courtship behavior -migratory behavior
courtship behavior
Theoretically, living organisms are capable of producing populations of infinite size. However, this never occurs because population sizes are limited by _______.
environmental conditions, the availability of resources, and organism interactions and behaviors
Which of the following resources can be in limited supply in an ecosystem? -food -sunlight -water -oxygen -shelter
food, water, sunlight, oxygen, and shelter.
An ecological interaction in which both organisms involved receive a benefit is known as
mutualism.
A female firefly recognizes males of her own species because the males give off a specific flash pattern. What type of behavior is a male exhibiting when he displays his flash pattern to a female?
social behavior
Plants require nitrogen and phosphorous but cannot efficiently absorb these nutrients from the soil. Instead, they obtain the nutrients through fungi that live in their roots. In return, the fungi have access to carbohydrates manufactured by the plants. Without the fungi, plants would not be healthy and abundant, and the food supply of all of the organisms in the ecosystem would be in danger. This is an example of how _______ relationships maintain balance within an ecosystem.
symbiotic
Which of the following historical events most likely triggered the largest increase in the human population?
the Industrial Revolution, which began in the late 1700s
Which of the following factors affected the world population size the most between 1300 and 1750(the black death)?
the death rate
Which of the following demonstrates a parasite/host relationship?
A tapeworm lives in the intestines of a dog and feeds upon the dog's ingested food.
The organisms within an established ecosystem interact and form relationships with each other over time. This interdependence allows ecosystems to remain relatively stable for hundreds and sometimes thousands of years. Which of the following would likely increase the population size of an established plant species? -an extended drought -a sudden change in climate -introduction of a non-native species -an increase in available nutrients
an increase in available nutrients
Lions and tigers are very similar creatures. However, lions live in groups, called prides, while tigers are largely solitary creatures. What might be an advantage for a female tiger leading a solitary life over a female lion living in a pride?
The tiger will have fewer threats to its cubs from others of its species.
In 1986, hundreds of islands were created out of hilltops when Venezuela was flooded because of a closed dam. On all of these new islands, the top predators in the food chain, such jaguars and eagles, either fled or died out. What most likely happened to the herbivores and smaller carnivores in those local food chains immediately after the predators disappeared?
Their populations increased.
Which of the following statements is true of all organisms in every environment?
They must compete for essential resources.
Which of the following demonstrates a predator/prey relationship? -A tapeworm lives in the intestines of a dog and feeds upon the dog's ingested food. -A giraffe eats the leaves of an Acacia tree. -Flies feed upon the carcass of a bull. -Using its tongue, a frog catches and eats a mosquito as it flies by.
Using its tongue, a frog catches and eats a mosquito as it flies by.
Many animals exhibit territorial behavior in order to protect a resource. An example of territorial behavior is a dog urinating in order to mark the boundaries of its territory. Is territorial behavior a form of social behavior?
Yes, territorial behavior is directed at members of the animal's species.
Which of the following events would most likely contribute to lowering the carrying capacity of a population? -a decrease in habitats due to human development or natural disasters -a decrease in the number of females in the population -an increase in the number of predators who eat the animal -an increase in the water supply in the habitat
a decrease in habitats due to human development or natural disasters
Which of the following is an example of predation? -a white-tailed deer consumes a plant in the forest for energy -an owl hunts, catches, and consumes a field mouse for energy -a tick attaches to the flesh of a dog and consumes its blood for energy -a tapeworm lives in the intestine of a cat and absorbs nutrients for energy
an owl hunts, catches, and consumes a field mouse for energy
Why might a red-winged blackbird—which is a territorial bird—ignore a rabbit in its territory, but violently fight off another red-winged blackbird?
because other red-winged blackbirds are competition for mates
The American bullfrog is native to much of the eastern United States. This species has successfully begun to spread west as an invasive species. It is thriving in the western United States because of its large size, high mobility, and tremendous reproductive capabilities. American bullfrogs have very generalized eating habits and often eat the same food sources as the native frog species in the western United States, causing a reduction in the overall food supply. The relationship between the American bullfrog and native frog species in the western United States can best be characterized as ______.
competition
A population of pheasants grew until it reached the maximum carrying capacity of an ecosystem. Then, the pheasants' food supply increased. As a result, the carrying capacity of the pheasants' habitat changed. Which graph could represent the history of the pheasant population?
graph looks like two S's, wavy but going up
Populations of typical prey animals, such as deer, might exceed the carrying capacity of an ecosystem if top predators, such as mountain lions, are removed. Without the mountain lions, increased numbers of deer may reduce the food supply available to other herbivores, such as field mice and crickets. As a result, populations of deer, mice, and crickets might decline, causing a population decrease in species that feed on these organisms as well. This example implies that properly functioning predator/prey relationships
maintain balance within an ecosystem.
The graph shows the population line at 13 climb at 7 months levels out at 10 months at around 33 then go back to its starting point at 20 months A dingo is a type of wild dog that feeds on frilled lizards. Which segment of the above population curve shows dingos feeding on the frilled lizards least actively?
months 7 to 10
Many kinds of plants depend on insects, such as moths, bees, wasps, and beetles, to perform pollination so they can reproduce. Meanwhile, the insect pollinator receives nectar or pollen as a food source from the flower of the plant. Thus, both organisms receive a benefit from this interaction. The biological relationship between a plant and its pollinator is known as _______.
mutualism
The Egyptian Plover bird and the crocodile are thought to have a certain symbiotic relationship. The bird gets a free meal by hunting the leeches on the crocodile, and the crocodile in turn gets rid of its leeches. What is the best description for such a relationship?
mutualism
Victor was studying the symbiotic relationship between a species of beetles and the species of tree the beetle lived in. The beetle obtained nectar and housing from the tree. At first, Victor believed the tree was neither helped nor harmed by the beetle, but then Victor witnessed the beetles attacking herbivore insects that tried to feed on the tree. What relationship exists between the tree and the beetles?
mutualism
Parasitism is a biological interaction in which
one organism benefits while the other organism is harmed.
Tapeworms cannot produce their own food. Instead, they live inside of another living organism's digestive tract and ultimately harm the organism as they absorb necessary nutrients from it. In the above relationship, the tapeworm is considered a _______ while the other organism is known as the _______.
parasite; host
A tick attaches to the flesh of a dog and feeds on the dog's blood for energy. This negatively impacts the dog by causing it discomfort and removing nutrients that the dog's body could have used for life processes, but it does not kill the dog. The interaction described above is known as
parasitism.
A cheetah hunts, kills, and eats a gazelle. This interaction is an example of _______.
predation
A pack of wolves kill and eat a deer. What kind of interaction takes place between the wolves and the deer?
predator/prey
A lion hunts, kills, and feeds on a zebra. The lion is an example of a _______, and the zebra is its _______.
predator; prey
The American bullfrog is an aquatic frog that is native to North America. Bullfrogs mate during early summer and can produce hundreds of thousands of tadpoles in a single body of water, which greatly increases the bullfrog population in the local ecosystem. Most of the tadpoles will die because of fish predation, disease, or starvation. This results in the local bullfrog population remaining relatively constant despite the large number of tadpoles produced during the breeding season. What best describes this summary of the bullfrog's ecosystem?
Cyclical changes occur in populations of organisms, but ecosystems stay in a state of approximate equilibrium.
Natalie is studying a population of Eastern Cottontail rabbits inhabiting a forest ecosystem. The population size of the rabbits has held steady for many months, but a wildfire has recently destroyed half of the vegetation that the rabbits use as a main food source. What will likely happen to the Eastern Cottontail rabbit population in this ecosystem?
It will fall sharply at first, then hold steady at a lower level until the vegetation returns.
Overpopulation occurs when a population exceeds its carrying capacity. White-tailed deer are considered to be an overpopulated species in the central United States. What is one consequence of white-tailed deer exceeding their carrying capacity?
The deer are less healthy and more prone to disease.
A kingfisher can be seen with a frog in its mouth. Which of the following can be concluded about the ecological relationship between these two species?
The kingfisher and the frog have a predator/prey relationship.
How does the first level of an energy pyramid affect the carrying capacity of the ecosystem?
The amount of energy in the first level determines how many animals can be supported on the subsequent levels.
Dutch elm disease is a disease that affects elm trees and is caused by a fungal species that infects the vascular systems of the tree. Over time, the fungus will spread through the vascular tissue and eventually result in a complete blockage that prohibits water and nutrient transport in the tree. Dutch elm disease is most commonly spread by elm bark beetles that can carry fungal spores on their body. When an infected beetle lands on a healthy elm tree to feed, the tree can become infected by the spores. As beetles move from tree to tree, more of the elm population can become infected. Suppose a forested area has many tree species, including elms. Elm bark beetles carrying the fungus that causes Dutch elm disease are accidentally introduced into the area by humans. The elm bark beetle population flourishes because of a lack of natural predators. What will most likely happen over time as the elm bark beetle population grows?
The death rate of the elm tree population will increase, causing an overall decrease in the elm tree population.
Wolves and foxes both hunt snowshoe rabbits. If there was an increase in the number of wolves, which of these is the most likely result?
The number of snowshoe rabbits would decrease, and the number of foxes would decrease.
