Practice: Energy, Life and the Biosphere

Name:

Multiple Choice

Identify the letter of the choice that best completes the statement or answers the question.

These organisms have the ability to change light energy into chemical energy.

a.	primary consumers	c.	producers
b.	secondary consumers	d.	decomposers

Figure 24.01

The data represent population size of plant plankton and animal plankton in a deep lake in the northern United States.

Refer to Figure 24.01 and the information above. The lake is in upper New York State.

a.	a reasonable interpretation of the data
b.	contradicted by the data
c.	not enough data to make the statement
d.	not an interpretation, but a restatement of the data

Refer to Figure 24.01 and the information above. There are no animal plankton in this lake during the winter.

a.	a reasonable interpretation of the data
b.	contradicted by the data
c.	not enough data to make the statement
d.	not an interpretation, but a restatement of the data

Refer to Figure 24.01 and the information above. There is a seasonal change in the levels of plant plankton.

a.	a reasonable interpretation of the data
b.	contradicted by the data
c.	not enough data to make the statement
d.	not an interpretation, but a restatement of the data

The energy pyramid teaches us

a.	only 50% of the energy on the producer level is passed on to the next higher level.
b.	eating meat from grain-fed cattle doesn’t make efficient use of the energy stored in producers.
c.	energy lost as heat or through cellular respiration is 10% of the absorbed energy.
d.	there is a greater variety of species at the higher trophic levels.

The root of the mistletoe plant grows into the xylem of a tree in order to secure nutrients.

This relationship is called

a.	competitive exlusion.	c.	commensalism.
b.	mutualism.	d.	parasitism.

Some are capable of nitrogen fixation (recycling nitrogen so it is usable again).

a.	plants	c.	decomposers
b.	bacteria	d.	consumers

Which of the following best describes free energy?

a.	chemical-bond energy
b.	heat or thermal energy
c.	energy available to the organism to do work
d.	energy stored in ATP

A food web

a.	consists of all of the abiotic and biotic factors in the environment.
b.	shows how all of the plants and animals are related.
c.	describes the relationship between the organisms and the environment.
d.	describes the energy and nutrient links between organisms in the environment.

Figure 02.01

10.

Refer to Figure 02.01. This diagram illustrates a(n)

a.	food chain.	c.	biosphere.
b.	food web.	d.	energy cycle.

11.

Refer to Figure 02.01. The only producers shown are

a.	grasses.	c.	mice.
b.	mushrooms.	d.	deer.

The diagram shows the flow of energy in a small portion of a simple grassland ecosystem. Use the diagram to answer the following questions.

Figure 02.02

12.

Refer to the Figure 02.02 diagram above. Where does most of the energy contained in the grasses end up?

a.	Most of the energy flows into grasshoppers.
b.	Most of the energy flows into the decomposers.
c.	Most of the energy is converted to heat.
d.	Most of the energy is converted to free energy.

13.

Refer to the Figure 02.02 diagram above. Energy flow in an ecosystem can be described as

a.	a one-way flow in which energy eventually leaves the ecosystem as heat.
b.	a recycling in which energy is returned to the ecosystem by decomposers.
c.	a downward flow in which energy accumulates in producers.
d.	a one-way flow in which all energy passes through decomposers.

14.

When a chemical reaction occurs in a cell and heat is given off,

a.	energy is destroyed in the reactions.
b.	pieces of molecules are broken off and removed from cells.
c.	there is less free energy available to the cell.
d.	cells can use the heat to synthesize large organic molecules.

15.

Which of the following best describes the effect of temperature on enzyme activity?

a.	For enzyme activity to be high, the cell must become as warm as possible.
b.	For enzyme activity to be high, the cell must become as cool as possible.
c.	For enzyme activity to be high, the cell must remain within a narrow range of temperatures.
d.	Temperature is not important, since the role of enzymes is to overcome the need for activation energy.

In the experiment described below, water was added to each of five test tubes, followed by yeast and sucrose. Sucrose is a double sugar, consisting of two simple sugars bonded together. One of the test tubes was boiled after the yeast was added, and one was chilled. After 10 minutes, the presence of glucose, a simple sugar, was determined. The experimental results are shown in the last column.

Test tube	Water added	Living yeast added	Sucrose added	Temperature treatment	Presence of glucose after 10 minutes
1	yes	no	no	room temperature	none present
2	yes	yes	no	room temperature	none present
3	yes	no	yes	room temperature	none present
4	yes	yes	yes	room temperature	glucose present
5	yes	yes	yes	test tube boiled after yeast added	none present
6	yes	yes	yes	test tube chilled after yeast added	trace of glucose present

16.

Refer to the information above. One possible conclusion that can be drawn from these data is

a.	living yeast are not able to convert sucrose into glucose.
b.	sucrose is not necessary to produce glucose.
c.	living yeast have the ability to convert sucrose to glucose.
d.	glucose may be present in water.

17.

Refer to the information above. The evidence that supports that yeast may be using an enzyme to convert sucrose to glucose is most clearly seen in

a.	test tubes 2 and 4, because living yeast was present in both test tubes.
b.	test tubes 5 and 6, since enzymes are affected by temperature.
c.	test tubes 1, 2, 3, and 6, since no glucose was detected in these test tubes.
d.	None of these data supports the fact that yeast may be using an enzyme to break down sucrose into glucose.

18.

Refer to the information above. The breakdown of sucrose into glucose is best described as a

a.	synthesis reaction.	c.	substrate reaction.
b.	decomposition reaction.	d.	free-energy reaction.

19.

Refer to the information above. Which of the following statements best describes the entropy and free energy in the test tubes before and after the test tubes?

a.	Test tube 1 had more free energy and more entropy at the beginning of the experiment than it did at the end.
b.	Test tube 4 had more free energy and more entropy at the end of the experiment than it did at the beginning.
c.	All of the test tubes had the same amount of free energy and entropy at the end of the experiment as they did at the beginning.
d.	Test tube 4 had less free energy and more entropy at the end than it did at the beginning of the experiment.

20.

The energy that we get from the food we eat is

a.	used directly to power cell reactions.
b.	converted to matter and stored.
c.	used in the production of ATP.
d.	used in the production of ADP.

21.

Oxidation is best described as

a.	the addition of oxygen to a molecule.
b.	the addition of electrons to a molecule.
c.	the formation of glycogen from glucose.
d.	the removal of electrons from a molecule.

22.

Physical digestion is important to some organisms because

a.	they may not have a stomach where they can perform chemical digestion.
b.	they may lack the necessary enzymes for chemical digestion.
c.	physical digestion requires less activation energy.
d.	physical digestion increases the surface area of the food.

23.

Most plants rely on intracellular digestion because

a.	they are digesting the food they made themselves in their own cells.
b.	they lack the necessary enzymes for extracellular digestion.
c.	they are able to extract more energy from their food when they rely on intracellular digestion.
d.	they only consume very small molecules that easily fit inside the cell.

24.

Which of the following would result if peristalsis stopped?

a.	Food would enter the trachea.
b.	Protein would not be digested properly.
c.	Carbohydrates would not be digested properly.
d.	Food would stop moving through the digestive tract.

25.

Water is removed from food and absorbed back into the body in

a.	the small intestine.	c.	the stomach.
b.	the large intestine.	d.	the kidneys.

26.

The pancreas

a.	secretes juices that raise the pH of the small intestine.
b.	secretes enzymes that prepare the stomach for the digestion of proteins.
c.	secretes juices that lower the pH of the stomach.
d.	is primarily responsible for the digestion of fats.

27.

Protein is digested in

a.	the stomach.
b.	the small intestine.
c.	the large intestine.
d.	both the stomach and the small intestine.

28.

The end products of digestion

a.	contain very little free energy.
b.	consist of complex organic molecules.
c.	are small enough that they can pass through the cells lining the small intestine.
d.	are all converted to glucose before being absorbed by the cells of the small intestine.

29.

The surface area of the small intestine is very large due to

a.	the length of the small intestine.
b.	the presence of villi.
c.	the many capillaries located on the surface.
d.	its ability to stretch during peristalsis.

30.

Which of the following are classified as heterotrophs?

a.	algae	c.	plants
b.	minerals	d.	mushrooms

31.

Free energy becomes available to organisms when

a.	nutrients are transported from one part of the cell to another.
b.	energy stored in one form gets converted to another form during chemical reactions.
c.	large organic molecules are stored.
d.	large organic molecules are synthesized.

32.

Scientists have found microorganisms that live deep beneath the surface of the ocean where light does not exist. These organisms obtain free energy from inorganic chemicals in the environment. These organisms are classified as

a.	heterotrophs.	c.	decomposers.
b.	producers.	d.	autotrophs.

33.

The energy contained in food is converted to free energy by the process of

a.	photosynthesis.	c.	cellular respiration.
b.	decomposition.	d.	digestion.

34.

Which of the following statements about nutrients and energy is true?

a.	Nutrients and energy can be obtained from both living and nonliving sources.
b.	Energy can be obtained from both living and nonliving sources, but nutrients must be obtained from living sources.
c.	All organisms need energy, but only consumers need nutrients.
d.	Both producers and consumers need energy, but only decomposers need nutrients.

35.

All Earth’s ecosystems together make up the

a.	biosphere.	c.	atmosphere.
b.	community.	d.	biotic world.

36.

In an ecosystem, these organisms are most likely to be the first to increase in population size.

a.	primary consumers	c.	producers
b.	secondary consumers	d.	decomposers

37.

Which of the following essential chemical elements is recycled?

a.	nitrogen	c.	water
b.	carbon	d.	all of the above

38.

The increase in carbon dioxide concentration in the atmosphere can be attributed to a rise in

a.	use of fertilizers and pesticides.
b.	use of fossil fuels.
c.	change in humans’ diets, including more fruits and vegetables.
d.	global warming.

39.

A gardener who has a compost heap knows that it works only if

a.	oxygen is present.	c.	decomposers are present.
b.	oxygen is absent.	d.	temperature is above 60°C.