Question 1

A population of beetles varies in shell color, with green and brown beetles present. After a forest fire, the ground becomes dark, and the brown beetles are less visible to predators. Over time, the relative frequency of brown beetles in the population increases. What is the role of genetic variation in this process?

Accepted Answer

Brown beetles were better camouflaged, and this trait existed in the population before the fire.

Question 2

Which of the following best describes the molecule shown below?

$$\begin{array}{c}
\mathrm{$$HOCH_2$$} \hspace{0.1cm} \mathrm{(hexagon)} \hspace{0.1cm} \mathrm{OH} \
\end{array}$$

Accepted Answer

Nucleotide

Question 3

What type of interactions are directly involved in the formation of protein tertiary structure?

Accepted Answer

More than one of the above

Question 4

A bacterium is an organism that obtains energy from inorganic chemicals and carbon from carbon dioxide. Which of the following statements is correct about this species?

Accepted Answer

It is a bacterium and a chemoautotroph

Question 5

Hair and nail cells are very rich in which cytoskeletal element?

Accepted Answer

Intermediate filaments

Question 6

Amoeba proteus is a small protozoan that uses tentacle-like extensions called pseudopodia to engulf smaller unicellular organisms. This process is an example of the function of which cytoskeletal element?

Accepted Answer

Actin

Question 7

Glucose is broken down into carbon dioxide and water, releasing energy. Which of the following explains why this process is spontaneous?

Accepted Answer

The reaction has a negative enthalpy change ($$\Delta H) $$and a positive entropy change ($$\Delta S$$), leading to a negative Gibbs free energy ($$\Delta G).$$

Question 8

Enzymes do NOT ________.

Accepted Answer

Change the free energy of a reaction.

Question 9

HIV protease inhibitors are drugs that bind to the active site of the HIV protease enzyme, preventing the enzyme from functioning. This is an example of which type of enzyme inhibition?

Accepted Answer

Competitive inhibition

Question 10

A eukaryotic cell is lacking cytoplasmic tubulin. Which is the most likely result?

Accepted Answer

All of the above are likely.

Question 11

A small child has a very high fever. Why is this potentially dangerous if it stays very high for long?

Accepted Answer

An increased temperature can break bonds and alter the structure of proteins.

Question 12

Which of the following best describes the relationship between $$\Delta G$$, $$\Delta H$$, and $$\Delta S in a $$spontaneous reaction at constant temperature?

Accepted Answer

$$\Delta G = \Delta H - T\Delta S$$ and $$\Delta G \u003c 0$$

Question 13

Which of the following is NOT a function of microtubules in eukaryotic cells?

Accepted Answer

Facilitating muscle contraction

Question 14

Which of the following statements about enzymes is FALSE?

Accepted Answer

Enzymes change the equilibrium position of a reaction.

Question 15

A scientist discovers a new organism that can move using pseudopodia, engulfs food particles, and lacks a cell wall. Which of the following is most likely true about this organism?

Accepted Answer

It is a eukaryote and likely a protist.

Question 16

Which of the following best explains why antibiotics that target bacterial ribosomes do not harm human cells?

Accepted Answer

Bacterial ribosomes are structurally different from eukaryotic ribosomes.

Question 17

Which of the following is a direct result of the denaturation of a protein?

Accepted Answer

The protein loses its three-dimensional shape and function.

Question 18

Which of the following is a real-world example of feedback inhibition?

Accepted Answer

ATP inhibits an enzyme involved early in glycolysis when ATP levels are high.

Question 19

Which of the following best describes the effect of a noncompetitive inhibitor on enzyme activity?

Accepted Answer

It binds to a site other than the active site and decreases the maximum reaction rate ($$V_{max}).$$

Question 20

Which of the following statements about spontaneous chemical reactions is TRUE?

Accepted Answer

Spontaneous reactions have a negative change in free energy ($$\Delta G \u003c 0).$$

General Biology: Midterm 1 Practice Questions Study Guide

Guida di studio - Domande di pratica

Study guide - Flashcard