praxis elementary science 5005 practice test

A series of tests developed by ETS to assess the skills and knowledge of prospective teachers.

CHESAPEAKE BAY FOOD WEB
Based on the food web shown, which of the following is true about the feeding relationships?
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  • A. Bivalves have no natural predators in the Chesapeake Bay ecosystem.
  • B. Wading birds are herbivores that eat aquatic vegetation.
  • C. Phytoplankton are producers that convert light energy into organic matter.
  • D. Sea ducks are primary consumers that eat only bald eagles.
Correct Answer & Rationale
Correct Answer: C

In the food web, phytoplankton are classified as producers because they perform photosynthesis, converting light energy into organic matter. This foundational role supports the entire ecosystem. Option A is incorrect; bivalves often have predators, such as certain fish and birds, that feed on them. Option B misclassifies wading birds, which are carnivores that primarily feed on small fish and invertebrates, not herbivores. Option D is misleading, as sea ducks are primary consumers but do not exclusively eat bald eagles; they primarily consume aquatic plants and invertebrates. Thus, option C accurately reflects the role of phytoplankton in the ecosystem.

Other Related Questions

Which THREE of the following are health problems associated with long-term exposure to air pollution?
  • A. Accelerated aging of the lungs
  • B. Increased lung capacity
  • C. Increased risk of asthma
  • D. Increased risk of cardiovascular disease
Correct Answer & Rationale
Correct Answer: A,C,D

Long-term exposure to air pollution can lead to several significant health issues. Option A, accelerated aging of the lungs, is accurate as pollutants can damage lung tissue over time, reducing function. Option C is also correct; exposure to air pollution is linked to a higher incidence of asthma, particularly in children, due to airway inflammation and increased sensitivity. Option D is valid as well; numerous studies show that air pollution significantly raises the risk of cardiovascular diseases due to systemic inflammation and oxidative stress. Conversely, Option B, increased lung capacity, is incorrect. Air pollution typically impairs lung function rather than enhancing it, leading to reduced capacity over time.
Which of the following best predicts what will happen when white light passes through a green object?
  • A. The object will mostly reflect the green part of the light.
  • B. The object will mostly absorb the green part of the light.
  • C. The object will appear black.
  • D. The object will appear white.
Correct Answer & Rationale
Correct Answer: A

When white light passes through a green object, the object primarily reflects green wavelengths while absorbing others. This reflection causes the object to appear green to our eyes. Option B is incorrect because if the object absorbed the green part of the light, it would not appear green. Option C is not valid, as a black appearance would result from the object absorbing all wavelengths of light, not reflecting any. Option D is also wrong; an object appears white when it reflects all wavelengths of light equally, which does not apply to a green object.
The rotation of Earth around its axis is responsible for which of the following?
  • A. The force of gravity
  • B. The day and night cycle
  • C. The temperature differences between seasons
  • D. The movement of continents relative to one another
Correct Answer & Rationale
Correct Answer: B

The rotation of Earth around its axis creates the day and night cycle, as different parts of the planet face the Sun and then move into its shadow. This explains why we experience daytime and nighttime in a 24-hour period. Option A is incorrect; gravity is primarily caused by Earth's mass, not its rotation. Option C is also wrong; temperature differences between seasons are due to Earth's tilt and its orbit around the Sun, not its rotation. Lastly, option D misrepresents the concept; the movement of continents is influenced by tectonic activity, not the rotation of Earth.
Which of the following is a nonrenewable fossil fuel?
  • A. Coal
  • B. Uranium
  • C. Geothermal energy
  • D. Ethanol
Correct Answer & Rationale
Correct Answer: A

Coal is a nonrenewable fossil fuel formed from ancient organic matter subjected to heat and pressure over millions of years. It is finite and cannot be replenished on a human timescale. Uranium (B) is a nonrenewable resource used in nuclear energy production but is not classified as a fossil fuel. Geothermal energy (C) harnesses heat from the Earth and is considered renewable. Ethanol (D) is a biofuel derived from plant materials, making it renewable as it can be produced continuously. Thus, coal stands out as the only nonrenewable fossil fuel in this list.