Science Practice Questions — Set 6

Question 1

Why is antibiotic resistance considered a major example of natural selection?

Accepted Answer

The antibiotics kill susceptible bacteria, but resistant bacteria survive and reproduce.

Answer

The human body evolves to become weaker against the bacteria.

Answer

Antibiotics directly cause mutations that make bacteria stronger.

Answer

The bacteria "decide" to become resistant and change their DNA.

Question 2

A patient's blood test shows low oxygen levels and high carbon dioxide levels. This indicates a failure of which two body systems to interact properly?

Accepted Answer

Respiratory and Circulatory

Answer

Circulatory and endocrine systems are mismatched.

Answer

Nervous and respiratory systems

Answer

Digestive and nervous systems

Question 3

A cell needs to move a substance from a low concentration inside to a high concentration outside. Which process must it use?

Accepted Answer

Active Transport

Answer

Osmosis

Answer

Simple Diffusion

Answer

Facilitated Diffusion

Question 4

What is the *most likely* immediate effect of a single base-pair mutation (like A -> G) in a DNA sequence?

Accepted Answer

It might change a single amino acid in a protein.

Answer

All mutations are silent and always repaired before any effect.

Answer

It will cause the entire organism to die.

Answer

It will stop the cell from ever dividing again.

Question 5

Why does a wound stop bleeding?

Accepted Answer

Platelets gather at the site and form a plug.

Answer

Skin cells divide rapidly to cover the wound surface.

Answer

White blood cells attack the wound and seal it.

Answer

Red blood cells change shape and block the opening.

Question 6

You are cold, so your body shivers. Shivering is an example of:

Accepted Answer

A homeostatic response

Answer

A reflex-arc response

Answer

Natural selection process

Answer

A muscle response that generates heat

Question 7

If you boil an enzyme (like one that digests protein), it stops working. Why?

Accepted Answer

The enzyme's shape is altered (denatured).

Answer

Boiling makes the enzyme reaction too fast to observe.

Answer

The water dilutes the enzyme.

Answer

Enzymes are living organisms that get killed by boiling.

Question 8

A person with Type A blood receives a transfusion of Type B blood. What will happen?

Accepted Answer

The recipient's antibodies will attack the Type B blood cells.

Answer

The recipient's blood will be converted to Type AB.

Answer

Nothing; all human blood is compatible.

Answer

The recipient will be cured of any disease.

Question 9

Two different organisms are in the same *Order*. What other classification level *must* they also share?

Accepted Answer

Class

Answer

Genus

Answer

Species

Answer

Family

Question 10

An element is in Group 1 (Alkali Metals) of the periodic table. What is its *most likely* property?

Accepted Answer

It is highly reactive and forms a +1 ion.

Answer

Gold is hard, non-reactive, and difficult to cut.

Answer

It is a non-reactive gas.

Answer

It forms a -1 ion.