WorksheetsUnit 6-Ecology
Total questions: 20
Worksheet time: 10mins
Which of the diagrams below shows an example of secondary succession in an ecosystem? Please notice each image is an answer choice (A, B, C, D). (L.17.5 – Sub Cat. 17.4)
A
B
C
D
The diagram below shows a specific nutrient cycle in nature. What is the function of the autotrophs shown in the picture below in this cycle? (L.17.9 – Sub Cat. 17.10)
To use oxygen to produce glucose
To take in excess water
To use carbon dioxide to produce glucose
To feed on herbivores
A simplified food web is shown. Suppose the bird population declines due to a shortage of nesting sites. Which organism would be most negatively affected by a decline in the bird population? (L.17.5)
spider
snake
grass
toad
Which environmental factor would cause the greatest decrease in the number of species of plants and animals living in some of the lakes in the United States? (L.17.20)
increase in dissolved oxygen levels
global warming
ozone destruction
acid rain
Which graph shows the changes in global human population and natural resource use over the past 500 years? Please notice each graph is an answer choice. (L.17.20)
A
B
C
D
A student wanted to investigate the transpiration rate of a plant species at varying levels of humidity. The results are recorded in the table shown. Each plant group was given the same amount of water and light throughout the investigation. Which procedures should have been performed to prevent error in this investigation? (N.1.1)
Another plant species should have been tested.
Fewer plants should have been included in each group.
The percentage of humidity should have been kept constant.
Both groups should have been tested in the same soil type at each humidity level.
A biologist gathered data to show the interaction of the golden-cheeked warbler (bird) and juniper tree populations. Which conclusion did the biologist most likely make from the data shown? (N.1.1)
As the juniper tree population increases, the golden-cheeked warbler population increases.
The optimum habitat for the golden-cheeked warbler population is 100 juniper trees per acre.
The golden-cheeked warbler population stabilizes when the juniper tree population increases above 120 trees per acre.
A golden-cheeked warbler population is unable to survive if juniper trees are present.
Which of the following should be a characteristic of a stable ecosystem? (L17.5 – Sub Cat. 17.8)
A high number of predators and a lesser number of producers
A lack of interdependence of organisms
An increase in human interference
An abundance of biodiversity
A sea turtle has washed up on a remote section of a beach. This is known as a “stranding.” Stranding occurs when a dead, sick or injured sea turtle washes up on the shoreline. Which statement best explains why “stranding” should be reported immediately to local authorities? (L17.20)
The information can be very useful to biologists and managers who are trying to protect the species.
The information can be very useful to protect sea turtles from predators.
The information can be very useful to local fishermen who try to catch fish that sea turtles eat.
The information can be very useful to tourists who may want to keep sea turtles as pets
An estuary collects sediments from the ocean and rivers that feed into it. The sediments swirl around and then settle to form a mudflat. Eelgrass is then established on the mudflat. The ecosystem changes over time and ultimately develops into a salt marsh that contains mangrove trees. Which of the following is likely NOT involved in this example of aquatic ecological succession? (L17.5 – Sub Cat. 17.4)
The rotting remains of plants add to the fertility of the soil.
The soil becomes so fertile that eelgrass is replaced by other plant species.
The roots from plants help stabilize the sediment, keeping it in place.
The concentration of salt becomes so high that all plant life is destroyed.
What will most likely happen if the human population continues to grow and carelessly emit gases?
Too many greenhouse gases in the atmosphere may block heat from escaping into space and trap too much heat next to the Earth causing earthquakes.
Too many greenhouse gases in the atmosphere may block heat from escaping into space and trap too much heat next to the Earth’s surface creating a hole in the ozone layer
Too many greenhouses gases in the atmosphere may block heat from escaping into space and trap too much heat next to the Earth’s surface causing volcanic eruptions.
Too many greenhouse gases in the atmosphere may block heat from escaping into space and trap too much heat next to the Earth’s surface causing global warming.
This table below was found in a journal of a student in a research class. Analyze the table and determine which variables are constant, which is independent, and which is dependent then place them in the correct order (boxes). (N.1.1)
Fractional activity in box 1, water in box 2, starch solution in box 3, enzyme in box 4, temperature in box 5.
Fractional activity in box 1, temperature in box 2, water in box 3, starch solution in box 4, enzyme in box 5.
Temperature in box 1, enzyme in box 2, starch solution in box 3, water in box 4, fractional activity in box 5.
Temperature in box 1, fractional activity in box 2, water in box 3, starch solution in box 4, enzyme in box 5.
The picture shows a pika, a small mammal found in grassland ecosystems. The vast grasslands of the Tibetan plateau are home to the plateau pika. The numerous pikas are prey for many predators of the grasslands, which serve as a major watershed for much of the area. The watershed drains large quantities of groundwater during the rainy season, or the monsoon season.
Pikas have extensive burrows that help drain groundwater rapidly and are used as nesting sites by many bird species. However, many people advocate the eradication of the plateau pikas because they compete with livestock for grass. Which of these will most likely happen if the plateau pikas are completely removed from the Tibetan plateau grasslands? (L.17.5 – Sub Cat. 17.8)
The ecosystem will become unstable because predators will have fewer prey, the birds will have fewer nesting sites, and the area downriver will become vulnerable to flooding without the burrows to aerate the soil and provide drainage for monsoon rains.
The ecosystem will become more stable because the pika will be replaced by other species of small mammals that can fill the niche, bird species will adapt to nesting aboveground, and the soils will become compacted without the burrows.
The ecosystem will become unstable because the predators will migrate to nearby ecosystems, the birds will nest in nearby trees, and the soils will be aerated by other small mammals.
The ecosystem will become more stable because the pika will no longer be there to eat the grasses, the birds will migrate to other ecosystems during nesting season, and the soils will be able to absorb more of the monsoon rains without the pika burrows.
The energy pyramid below shows the energy made available by producers (L.17.9) How much energy would be expected to be found at the secondary consumer level in this pyramid?
100 joules
500 joules
1000 joules
50 joules
Analyze the diagram below and determine which cycle is represented. (L17.9 – Sub Cat. 17.10)
nitrogen cycle
water cycle
hydrosphere cycle
carbon cycle
Ecosystems must recuperate after catastrophes such as fires or hurricanes. A forest experiences a fire due to warm climate. Months after the fire, some nonnative plants began to grow in the area. Why were these plants able to grow? (L.17.20 – Sub Cat. 17.4)
The plants were able to survive without water.
The plants were able to use the ash as chemical energy.
The plants were able to thrive in the newly formed niche
The plants were able to mutate to adjust to the new surface materials.
Which of the following is most likely to cause the greatest disruption to an ecosystem? (L.17.20)
Emptying an aquarium containing non-native species into a local waterway
Cutting down a small cedar tree to make holiday decorations
Cleaning the windshield of a car with an alcohol-based glass cleaner
Mowing the lawn in a city park
Food webs such as the one shown were first used in 1927 by the animal ecologist Charles Elton. The food web below represents the feeding relationships among organisms in an Alaskan ecosystem (L.17.9)
Which of the following transfers is the most energy efficient?
Phytoplankton → Zooplankton → Sand lances → Gulls → Rats → Foxes
Phytoplankton → Zooplankton → Cephalopods → Puffins → Rats → Foxes
Phytoplankton → Zooplankton → Sand lances → Kittiwakes → Rats → Foxes
Phytoplankton → Zooplankton → Salmon → Puffins → Foxes
The following section focuses on the elk population in Yellowstone National Park. Read the information below and use it to answer the multiple-choice questions that follow.
Yellowstone National Park is a large wildlife area located mostly in Wyoming. Yellowstone is home to many species of mammals, including elk. The elk feed on grasses and on cottonwood, aspen, and willow trees. Historically, a significant portion of the elk population died each winter because winters in Yellowstone were long and very cold, with deep snow. Over the past 50 years the climate in Yellowstone has become warmer and snowfall amounts have decreased. More elk have been surviving the winters, but populations of scavengers have been decreasing. Scavengers feed on the carcasses of animals. The reintroduction of gray wolves to Yellowstone in the 1990s has affected elk population size and has contributed to the recovery of some scavenger populations. Wolves prey on elk and other animals.
When wolves make a kill, they feed until they are full and then they leave the carcass behind. Researchers have studied the changes in elk mortality (number of deaths) in Yellowstone by using data and mathematical models to calculate the average number of elks that die (represented by number of carcasses) from November to April each year. The results, with wolves present and without wolves present, are shown in the graph below.
Based on these data, scientists can estimate the size of scavenger populations through the winter. The graph below shows the size of a scavenger population with wolves present and without wolves present.
What is the most likely carrying capacity for the scavengers in the Yellowstone National Park? (L.17.5)
550
300
450
250
Yellowstone National Park is a large wildlife area located mostly in Wyoming. Yellowstone is home to many species of mammals, including elk. The elk feed on grasses and on cottonwood, aspen, and willow trees. Historically, a significant portion of the elk population died each winter because winters in Yellowstone were long and very cold, with deep snow. Over the past 50 years the climate in Yellowstone has become warmer and snowfall amounts have decreased. More elk have been surviving the winters, but populations of scavengers have been decreasing. Scavengers feed on the carcasses of animals. The reintroduction of gray wolves to Yellowstone in the 1990s has affected elk population size and has contributed to the recovery of some scavenger populations. Wolves prey on elk and other animals.
When wolves make a kill, they feed until they are full and then they leave the carcass behind. Researchers have studied the changes in elk mortality (number of deaths) in Yellowstone by using data and mathematical models to calculate the average number of elks that die (represented by number of carcasses) from November to April each year. The results, with wolves present and without wolves present, are shown in the graph below.
Based on these data, scientists can estimate the size of scavenger populations through the winter. The graph below shows the size of a scavenger population with wolves present and without wolves present.
What is the most likely carrying capacity for the scavengers in the Yellowstone National Park? (L.17.5)
Number of scavengers, number of wolves, number of scientists studying Yellowstone.
Number of scavengers, and harshness of winter.
Number of wolves, and harshness of winter.
The elk have no limiting factors.
