Question 1

Which of the following statements best describes the fundamental structural difference between prokaryotic and eukaryotic cells?

Accepted Answer

Prokaryotic cells lack a membrane-bound nucleus, while eukaryotic cells possess a membrane-bound nucleus.

Question 2

A patient’s blood glucose level rises after a meal, triggering the pancreas to release insulin, which lowers blood glucose. This is an example of:

Accepted Answer

Negative feedback

Question 3

In a phylogenetic tree, which of the following best describes the most recent common ancestor of two species?

Accepted Answer

The node where the lineages of the two species diverge

Question 4

Which of the following best illustrates adaptive radiation?

Accepted Answer

A single ancestral species rapidly diversifies into many new species, each adapted to a different environment.

Question 5

Which of the following correctly lists the basic steps of the scientific method in order?

Accepted Answer

Observation, hypothesis, experiment, analysis, conclusion

Question 6

Which of the following statements best distinguishes a scientific theory from a hypothesis?

Accepted Answer

A theory is a broad explanation supported by a large body of evidence, while a hypothesis is a testable prediction.

Question 7

Which of the following elements make up over 90% of the human body by mass?

Accepted Answer

Oxygen, carbon, hydrogen, and nitrogen

Question 8

The atomic number of an element is determined by the number of:

Accepted Answer

Protons

Question 9

Why can’t you change the number of protons in an atom without changing the element?

Accepted Answer

The number of protons defines the element’s identity.

Question 10

Which of the following best describes the difference between a molecule and a compound?

Accepted Answer

A molecule consists of two or more atoms bonded together, while a compound consists of two or more different elements bonded together.

Question 11

Which type of bond is most likely to form between two atoms with a large difference in electronegativity?

Accepted Answer

Ionic bond

Question 12

Given an element with atomic number $$Z = 12$$ and atomic mass $$A = 24$$, how many neutrons does it have?

Accepted Answer

$$12$$

Question 13

What type of bond holds the hydrogen and oxygen atoms together within a single water molecule?

Accepted Answer

Polar covalent bond

Question 14

Which property of water is primarily responsible for its high surface tension?

Accepted Answer

Cohesion due to hydrogen bonding

Question 15

Why does ice float on liquid water?

Accepted Answer

Ice is less dense than liquid water due to the formation of a crystalline lattice.

Question 16

The pH of a solution is a measure of:

Accepted Answer

The concentration of hydrogen ions ($$[H^+])$$

Question 17

What is the primary function of a buffer in a biological system?

Accepted Answer

To minimize changes in pH when acids or bases are added

Question 18

Why is the acidification of seawater by absorbed $$CO_2 a $$serious problem for marine life?

Accepted Answer

It reduces the availability of carbonate ions needed by organisms to build shells and skeletons.

Question 19

Which functional groups are always found in amino acids?

Accepted Answer

Amino group ($$-NH_2$) and carboxyl group (-$$COOH$$)

Question 20

Which of the following best describes the difference between cis and trans isomers?

Accepted Answer

Cis isomers have substituents on the same side of a double bond, while trans isomers have them on opposite sides.

General Biology Study Guide: Step-by-Step Guidance for Key Concepts

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