Jenn and Murphy are studying data from a small forest ecosystem in a city park. The data indicates that the deer population in the forest has grown significantly over the last several years. Why will the size of the deer population most likely decrease in the next few years?

Environmental factors, such as temperature, can significantly affect the populations in an ecosystem. A group of scientists studied the sycamore lace bug (Corythucha ciliata) to determine how it is affected by the temperature of its environment. The scientists allowed batches of eggs to hatch and the larvae to grow to adulthood at five different temperatures. The survival rates of the lace bug at each temperature are on the graph.

Which is an example of an effect an abiotic factor could have on a population in an ecosystem?

Nutria are large semiaquatic rodents that were imported from South America to the United States by fur traders. In the late 1940s, a hurricane dispersed nutria throughout southeast Texas. They feed on native seedlings and saplings—native organisms that are naturally found in the ecosystem—and have cleared wide areas of floodplains and marshland along the Gulf Coast.

 Which is most likely the effect of the introduction of nutria into southeast Texas ecosystems?

Pink salmon return to the same waters in which they were born to mate. Researchers collected data on the pink salmon returning to Auke Creek and the average water temperature. Table 1 shows the calendar dates of the highest percentage of pink salmon returning to Auke Creek in Juneau, Alaska, to mate in six years spanning from 1971–2010. Table 2 shows changes in the creek during the same time period.

The data in Table 1 and Table 2 show the relationship between salmon and which abiotic factor?

Observe the food web below. Which populations directly compete with owls for food?

Eutrophication occurs when algae grow rapidly and then die and decompose. The process of decomposing uses lots of oxygen. Fish in the water depend on oxygen to survive. What is the most likely effect of eutrophication on fish?

A scientist observes the plants in a forest ecosystem. In the spring, she notices that the wildflowers on the forest floor sprout and grow leaves before leaves grow on the trees. What is the best explanation for this observation?

Which of the following are examples of competition?

Select the 2 correct answers.

The Texas shiner is a type of fish found in the Edwards Plateau region of Texas. It is a predator. It typically lives in groups called schools.

Which best explains how the size of the school affects competition for resources?

the demand for resources, such as food, water, and shelter, in short supply in an ecosystem

a factor that can limit the growth of a population.

any nonliving factor in an organism’s environment, such as soil, water, temperature, and light availability.

any living factor in an organism’s environment.

Organisms depend on and compete for biotic and abiotic factors within their ecosystems for survival. Imagine a pond ecosystem that has tall trees, clear pond water, bright sunlight, thick soil, colorful flowers, and tall grass.

Which statement BEST explains how the population of grass depends on an abiotic factor present in the ecosystem?

A population of lizards in a desert ecosystem depends on biotic and abiotic factors in order to survive.

Which statement correctly lists a biotic factor AND how the lizard population depends on it to survive?

A scientist investigates the type of food that different populations in the same ecosystem depend on during a typical week. The observations are recorded in this table.

Based on the data, which statement BEST describes organisms that are competing for food resources?