Big Ideas in Science — Module Assessment

Question 1

For natural selection to change a population over generations, a trait must vary, be heritable, and:

Accepted Answer

affect survival or reproduction in the environment

Answer

be visible to the human eye

Answer

have appeared through a deliberate mutation

Answer

be present in every individual equally

Question 2

Why does the objection "evolution is just a theory" misunderstand science?

Accepted Answer

In science a theory is a well-tested explanation backed by evidence, not a guess

Answer

Scientists never actually use the word theory

Answer

Evolution has been formally reclassified as a law

Answer

A theory in science means an idea no one has tested yet

Question 3

What did Rutherford conclude from the gold-foil experiment, in which most particles passed through the foil but a few bounced sharply back?

Accepted Answer

An atom's mass and positive charge are concentrated in a tiny central nucleus

Answer

Atoms are indivisible solid spheres

Answer

Electrons travel in fixed planetary orbits

Answer

All elements are made of the same single kind of atom

Question 4

Why are scientists confident atoms exist even though no one saw one when the theory was built?

Accepted Answer

Many independent experiments produce consistent results that only atoms explain

Answer

A famous scientist declared it and others agreed

Answer

Atoms were guessed at and never actually tested

Answer

The idea simply sounds reasonable

Question 5

How is Einstein's relativity best described in relation to Newton's physics?

Accepted Answer

It refined Newton's picture at extreme speeds and gravities, reducing to Newton in the everyday world.

Answer

It proved Newton's laws were entirely wrong.

Answer

It replaced energy conservation with a new rule.

Answer

It applies only to objects at rest.

Question 6

A ball dropped from a height speeds up as it falls. What does the conservation of energy say is happening?

Accepted Answer

Stored gravitational energy is converting into energy of motion, with the total conserved.

Answer

Energy is being created by the fall.

Answer

Energy is destroyed as the ball approaches the ground.

Answer

The ball gains energy from the surrounding air.

Question 7

Why does looking at a very distant galaxy let astronomers see into the past?

Accepted Answer

Light takes time to travel, so light arriving now left the galaxy long ago.

Answer

Distant galaxies are frozen in time.

Answer

Telescopes reverse the flow of time.

Answer

Galaxies age more slowly the farther away they are.

Question 8

The 1965 discovery of the cosmic microwave background by Penzias and Wilson supported the Big Bang because it was:

Accepted Answer

A faint, sky-filling afterglow the theory had predicted, left over from the hot early universe.

Answer

Direct radio contact with a distant galaxy.

Answer

Proof that the universe is not expanding.

Answer

A signal pinpointing the exact center of the explosion.

Question 9

In Mendel's pea experiments, why could a trait absent in both parents appear in their offspring?

Accepted Answer

Each parent carried a hidden recessive allele that combined in the offspring.

Answer

The trait was created fresh by the cross rather than inherited.

Answer

The parents' traits blended and then unmixed by chance.

Answer

The environment triggered a brand-new characteristic.

Question 10

What was Rosalind Franklin's crucial contribution to the 1953 discovery of DNA's structure?

Accepted Answer

X-ray diffraction images, including Photo 51, that revealed DNA's helical form.

Answer

The first written proposal that genes are made of protein.

Answer

Breeding experiments that established dominant and recessive ratios.

Answer

The naming of the four bases as A, T, C, and G.

Question 11

Which statement best describes the physical basis of the greenhouse effect?

Accepted Answer

Certain gases absorb outgoing infrared heat and re-radiate part of it back toward the surface.

Answer

Sunlight is blocked from reaching the surface by a layer of gas.

Answer

Carbon dioxide reflects sunlight back to Earth like a mirror.

Answer

The oceans release stored sunlight directly into the atmosphere at night.

Question 12

What does the Keeling Curve, begun by Charles David Keeling at Mauna Loa in 1958, primarily show?

Accepted Answer

A steady long-term rise in atmospheric carbon dioxide with a regular seasonal zigzag.

Answer

A one-time spike in carbon dioxide during a single volcanic eruption.

Answer

That carbon dioxide levels stay perfectly constant year to year.

Answer

Ocean temperature measured at the sea surface near Hawaii.

Question 13

According to the Planck satellite measurements finalised in 2018, roughly what fraction of the universe is ordinary matter?

Accepted Answer

About 5%

Answer

About 27%

Answer

About 68%

Answer

About 95%

Question 14

Which response to a genuine open question best reflects scientific thinking?

Accepted Answer

Treat it as a research question with clear standards of evidence for any answer.

Answer

Because it is unexplained, any proposed answer is equally valid.

Answer

Because it is unexplained, the whole field must be unreliable.

Answer

Avoid the question entirely, since unknowns cannot be studied.