Question

final exam environmental science 2021

1. which of the following is not true about natural gas?

a. natural gas is the dirtiest form of energy.
b. leaks in natural gas lines can cause explosions.
c. natural gas can be used for cooking food, heating homes, and fueling vehicles.
d. natural gases include butane, propane, and methane.

1. alligators will use their powerful feet, tail, and snouts to dig a hole through the mud, producing small ponds known as \alligator holes.\ many other species benefit from alligator holes. during the dry season, fish, turtles, and other aquatic animals live in the alligator holes. birds, terrestrial animals, and plants use these holes as a source of water. what term best describes the role of alligators in this ecosystem?

a. invasive exotic species
b. keystone species
c. producer
d. primary consumer

1. an experiment is performed on plants to see how different liquids affect plant growth. each plant in the experiment is given a different liquid: water, apple juice, or milk. each plant has the same amount of soil, sunlight, and listens to the same music. in this investigation, the dependent variable is ...

a. the amount of juice
b. the type of juice
c. the type of music
d. the amount the plants grow

1. as compared to developing countries, developed countries have a

a. higher average income, a higher rate of population growth, and produce more waste.
b. lower average income, a higher rate of population growth, and produce less waste.
c. higher average income, a lower rate of population growth, and produce more waste.
d. lower average income, a lower rate of population growth, and produce less waste.

Explanation:

Question 1

To determine which statement about natural gas is NOT true, we analyze each option:

• Option a: Natural gas (like coal, oil) releases CO₂ and other pollutants when burned, so it's not the dirtiest (e.g., coal is dirtier). But wait, actually, natural gas is cleaner than coal and oil in terms of carbon emissions per unit energy, but the "dirtiest form" claim—let's check others.
• Option b: Leaks in natural gas lines can cause explosions (methane is flammable), so this is true.
• Option c: Natural gas is used for cooking, heating, fueling vehicles, true.
• Option d: Natural gases include butane, propane, methane—true (they are hydrocarbon gases, part of natural gas or associated). Wait, maybe I misread. Wait, the question is "NOT true". Let's re-express: Natural gas's main component is methane, and it also has other hydrocarbons like butane, propane. But is "natural gas is the dirtiest form of energy" true? No—coal is dirtier (more CO₂, soot, heavy metals). So option a is false? Wait, no—wait, maybe the question's "dirtiest" is wrong. Wait, let's re-evaluate:

Wait, natural gas is cleaner than coal and oil. So saying it's the dirtiest is false. So option a is the false statement (NOT true).

Alligators create holes that benefit many species (birds, turtles, fish, plants) by providing water in dry seasons. A keystone species has a disproportionately large impact on its ecosystem relative to its abundance. Invasive species harm ecosystems, producers make energy, primary consumers eat producers. Alligators' role (creating critical habitats) fits keystone species.

In an experiment, the dependent variable is what's measured (depends on independent variable). Here, the experiment tests how liquid type (independent) affects plant growth (dependent). The dependent variable is the outcome measured: the amount the plants grow. The type of liquid is independent, amount of juice is not relevant, type of music is a distractor. So dependent variable is the amount the plants grow.

Answer:

a. Natural gas is the dirtiest form of energy.

Question 2