Question 1

Which of the following best explains why ice floats on liquid water, and what is the biological significance of this property?

Accepted Answer

Ice is less dense than liquid water because hydrogen bonds stabilize the molecules into a lattice, allowing aquatic life to survive under the ice during winter.

Question 2

A scientist is studying a newly discovered organism and observes that its genetic material is not enclosed within a membrane-bound nucleus. Which of the following statements is most accurate regarding this organism?

Accepted Answer

The organism is a prokaryote, and its DNA is located in a region called the nucleoid.

Question 3

Which of the following best describes the role of aquaporins in a cell membrane?

Accepted Answer

They facilitate the rapid movement of water molecules across the membrane via osmosis.

Question 4

A mutation changes a codon from $$\mathrm{UAC} to$$ $$\mathrm{UAG} in an $$mRNA sequence. What type of mutation is this, and what is its likely effect on the resulting protein?

Accepted Answer

This is a point mutation resulting in a nonsense mutation, likely leading to a truncated, nonfunctional protein.

Question 5

During glycolysis, glucose ($$\mathrm{C_6H_{12}O_6$}) is $$converted into two molecules of pyruvate. Which of the following statements about glycolysis is correct?

Accepted Answer

Glycolysis occurs in the cytoplasm and does not require oxygen.

Question 6

A researcher is studying the inheritance of two genes located on the same chromosome in fruit flies. She observes that the recombination frequency between these genes is 10%. What does this indicate about the physical distance between the genes?

Accepted Answer

The genes are 10 map units apart on the chromosome.

Question 7

Which of the following best describes the difference between starch and cellulose in plants?

Accepted Answer

Starch is composed of $$\alpha-$$glucose monomers and is used for energy storage, while cellulose is composed of $$\beta-$$glucose monomers and provides structural support.

Question 8

Which of the following scenarios best illustrates the concept of independent assortment?

Accepted Answer

During meiosis, alleles for different genes are distributed to gametes independently of one another.

Question 9

A patient is diagnosed with a disease caused by a frameshift mutation. Which of the following best describes a frameshift mutation and its likely effect?

Accepted Answer

A frameshift mutation results from the insertion or deletion of nucleotides not in multiples of three, altering the reading frame and usually producing a nonfunctional protein.

Question 10

Which of the following statements about the flow of genetic information in a cell is correct?

Accepted Answer

Information flows from DNA to RNA to protein, as described by the central dogma.

Question 11

Which of the following best explains why carbon is the backbone of organic molecules?

Accepted Answer

Carbon can form four covalent bonds, allowing for a diversity of stable and complex structures.

Question 12

A cell is placed in a solution and water moves into the cell, causing it to swell. Which of the following best describes the solution relative to the cell?

Accepted Answer

The solution is hypotonic to the cell.

Question 13

Which of the following is a function of telomerase in eukaryotic cells?

Accepted Answer

It extends the ends of linear chromosomes to prevent loss of genetic information during DNA replication.

Question 14

Which of the following best describes the function of ribosomes in a cell?

Accepted Answer

They are the sites of protein synthesis, translating mRNA into polypeptides.

Question 15

A scientist uses CRISPR-Cas9 to introduce a specific mutation into a gene. What is the primary function of the Cas9 protein in this system?

Accepted Answer

Cas9 acts as a nuclease that creates a double-stranded break at a targeted DNA sequence.

Question 16

Which of the following best describes the relationship between photosynthesis and cellular respiration?

Accepted Answer

Photosynthesis converts $$\mathrm{CO_2$}$$ and $$\mathrm{H_2O}$$ into glucose and $$\mathrm{O_2$}$$, while cellular respiration breaks down glucose and $$\mathrm{O_2$} to $$produce $$\mathrm{CO_2$}$$, $$\mathrm{H_2O}$$, and ATP.

Question 17

Which of the following statements about the scientific method is correct?

Accepted Answer

It involves making observations, forming hypotheses, conducting experiments, and drawing conclusions.

Question 18

Which of the following best describes a noncompetitive inhibitor's effect on an enzyme-catalyzed reaction?

Accepted Answer

It binds to a site other than the active site, changing the enzyme's shape and reducing its activity.

Question 19

Which of the following best explains why the maximum size of a cell is limited?

Accepted Answer

As a cell increases in size, its volume grows faster than its surface area, limiting efficient exchange of materials with the environment.

Comprehensive Study Guide for Introductory Biology: Final Exam Review

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