Question 1

Which of the following best describes the role of buffers in biological systems?

Accepted Answer

Buffers minimize changes in pH by accepting or donating hydrogen ions ($$\mathrm{H^+}) as $$needed.

Question 2

A scientist is designing an experiment to test the effect of a new fertilizer on plant growth. Which of the following is the best example of a dependent variable in this experiment?

Accepted Answer

The height of the plants measured after four weeks.

Question 3

Which of the following statements about water is correct and explains why sweating cools the human body?

Accepted Answer

Water's high heat of vaporization allows it to absorb a large amount of heat as it evaporates from the skin.

Question 4

Which of the following best explains why saturated fatty acids tend to be solid at room temperature, while unsaturated fatty acids are liquid?

Accepted Answer

Saturated fatty acids have straight chains due to single bonds, allowing molecules to pack tightly and form solids.

Question 5

A patient is diagnosed with a genetic disorder caused by a single nucleotide substitution in a gene. Which type of mutation could result in a premature stop codon and a truncated protein?

Accepted Answer

Nonsense mutation

Question 6

Which of the following best describes the function of the sodium-potassium pump in animal cells?

Accepted Answer

It uses ATP to actively transport $$3\ \mathrm{Na^+}$$ ions out of the cell and $$2\ \mathrm{K^+}$$ ions into the cell, maintaining the resting membrane potential.

Question 7

During cellular respiration, which process directly produces the most ATP?

Accepted Answer

Oxidative phosphorylation (electron transport chain and chemiosmosis)

Question 8

A cell is placed in a solution and begins to shrink. Which of the following best describes the tonicity of the solution relative to the cell?

Accepted Answer

The solution is hypertonic to the cell.

Question 9

Which of the following is a correct sequence of events during the light reactions of photosynthesis?

Accepted Answer

Water is split, electrons move through the electron transport chain, NADP$$^+ is $$reduced to NADPH, and ATP is produced by chemiosmosis.

Question 10

A researcher observes that a protein loses its function after being exposed to high temperatures but regains function when cooled. Which property of proteins does this observation illustrate?

Accepted Answer

Some proteins can renature and regain function if the primary structure is intact.

Question 11

Which of the following best explains why DNA replication is described as 'semiconservative'?

Accepted Answer

Each new DNA molecule consists of one parental strand and one newly synthesized strand.

Question 12

A woman with blood type AB and a man with blood type O have a child. Which of the following blood types could their child have?

Accepted Answer

Type A or Type B

Question 13

Which of the following best describes the function of tRNA during translation?

Accepted Answer

tRNA carries amino acids to the ribosome and matches its anticodon with the codon on mRNA.

Question 14

Which of the following scenarios best illustrates the concept of feedback inhibition in metabolic pathways?

Accepted Answer

The end product of a pathway binds to an enzyme that catalyzes an early step, decreasing its activity.

Question 15

Which of the following is a direct result of nondisjunction during meiosis in humans?

Accepted Answer

A child with Down syndrome (Trisomy 21)

Question 16

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

Accepted Answer

Eukaryotic cells have DNA located in a nucleus, while prokaryotic cells have DNA in the cytoplasm.

Question 17

A scientist is studying a metabolic pathway in which the product of the pathway inhibits the first enzyme in the pathway. Which type of regulation is this?

Accepted Answer

Feedback inhibition

Question 18

Which of the following best explains why the genetic code is described as 'degenerate'?

Accepted Answer

Multiple codons can specify the same amino acid.

Question 19

Which of the following is a correct description of the role of restriction enzymes in DNA biotechnology?

Accepted Answer

Restriction enzymes cut DNA at specific sequences, generating fragments with sticky or blunt ends.

Question 20

A cell with a diploid number of 8 chromosomes undergoes meiosis. How many chromosomes will each resulting gamete contain?

Accepted Answer

4

BIO-157 Fundamentals of Biology: Course Syllabus and Study Guide

Study Guide - Practice Questions

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