Week 1 Quiz

Biologists use a set of characteristics to decide whether something is alive. Which rule does this course use?

Select one.

• It is alive if it moves and grows on its own.
• It is alive only if it shows all seven characteristics of life.
• It is alive if it takes in energy, gives off heat, and changes over time.
• It is alive if it has a neat, ordered structure.

A candle flame grows when it is fed wax and gives off heat. Why does it still fail the checklist of life?

Select one.

• It does not move from place to place by itself.
• It is too hot for any living thing to survive.
• It does not reproduce its kind, regulate itself, or adapt over generations.
• It uses up energy, and living things only store energy rather than use it.

Which list puts these levels of organization in order from smallest to largest?

Select one.

• molecule, organelle, cell, organ, tissue, organism
• organelle, molecule, cell, tissue, organ, organism
• molecule, cell, organelle, tissue, organ, organism
• molecule, organelle, cell, tissue, organ, organism

A single heart muscle cell can twitch, but only the whole heart can pump blood. What does the pumping illustrate?

Select one.

• An emergent property of the organ level
• A characteristic of life that every single cell shows on its own
• A controlled variable in an experiment
• A theory that has not been tested

In the drops on a penny experiment (illustrative data), a penny is filled drop by drop with plain water and then with soapy water, three trials each. What is the dependent variable?

Select one.

• Plain water versus soapy water
• The number of drops before the water spills
• The same penny used for every trial
• The plain-water trials, used as the baseline

The three plain-water trials in the drops on a penny experiment held 28, 30, and 32 drops (illustrative data). What is the plain-water average?

Select one.

• 90 drops
• 32 drops
• about 31 drops
• 30 drops

In the drops on a penny experiment, plain water averaged 30 drops and soapy water averaged 14 drops, a difference of 16 drops. About what percent fewer drops did the soapy water hold, measured against the control?

Select one.

• About 53%, because 16 ÷ 30 ≈ 0.53
• About 114%, because 16 ÷ 14 ≈ 1.14
• About 47%, because 14 ÷ 30 ≈ 0.47
• About 16%, because 30 − 14 = 16

True or false: because the soapy-water trials averaged 16 fewer drops than the plain-water trials, the drops on a penny experiment proves that soap lowers the number of drops a penny holds.

True or false.

• True
• False

Which statement best describes a theory in science, such as the cell theory?

Select one.

• A guess that has not been tested yet
• A single prediction checked in one experiment
• A broad explanation backed by a large body of repeated tests
• A statement that can never be changed by new evidence

Which statements about evolution by natural selection match this course? Select all that apply.

Select every option that applies.

• Evolution is change in the heritable traits of a population over generations.
• Individuals with traits better suited to their environment survive and reproduce more.
• A single organism evolves during its lifetime when its surroundings change.
• Nearly all living things share the same genetic code, evidence of common ancestry.
• Evolution is a guess, because scientists call it a theory.