Q: Which of the following best describes the central dogma of molecular biology?

$$DNA \rightarrow RNA \rightarrow \text{Protein}$$

Question 1

Which of the following statements best summarizes the cell theory?

Accepted Answer

All living organisms are made up of one or more cells, and all cells arise from other pre-existing cells.

Question 2

Louis Pasteur's experiment with swan-necked flasks was important because it demonstrated that:

Accepted Answer

Cells do not arise by spontaneous generation, but from pre-existing cells.

Question 3

Which of the following best describes the central dogma of molecular biology?

Accepted Answer

$$DNA ightarrow RNA ightarrow 	ext{Protein}$$

Question 4

Which of the following is a key difference between a scientific theory and a hypothesis?

Accepted Answer

A theory is a well-supported explanation based on a body of evidence, while a hypothesis is a testable prediction.

Question 5

Which of the following best explains why water is an excellent solvent for polar and ionic substances?

Accepted Answer

Water molecules are polar and can form hydrogen bonds and electrostatic interactions with ions and polar molecules.

Question 6

Which of the following types of chemical bonds is primarily responsible for the unique properties of water, such as high cohesion and surface tension?

Accepted Answer

Hydrogen bonds

Question 7

A scientist is comparing the boiling points of water and ethanol. Water has a much higher boiling point. Which property of water is most responsible for this difference?

Accepted Answer

Water's ability to form extensive hydrogen bonds between molecules

Question 8

Which of the following statements about the structure of DNA is correct?

Accepted Answer

The two strands of DNA run antiparallel and are held together by hydrogen bonds between complementary bases.

Question 9

A segment of double-stranded DNA is found to contain 28% guanine. What is the percentage of adenine in this segment?

Accepted Answer

22%

Question 10

Which of the following best describes the difference between saturated and unsaturated fatty acids in phospholipids?

Accepted Answer

Saturated fatty acids have no double bonds and pack tightly, while unsaturated fatty acids have one or more double bonds and create kinks.

Question 11

A red blood cell is placed in pure water. What will happen to the cell, and why?

Accepted Answer

It will swell and burst because water is hypotonic compared to the inside of the cell.

Question 12

Which of the following amino acids would most likely be found in the interior of a transmembrane protein embedded in a lipid bilayer?

Accepted Answer

A hydrophobic amino acid like valine

Question 13

Which of the following statements about protein structure is correct?

Accepted Answer

Primary structure is the sequence of amino acids, and it determines all higher levels of structure and function.

Question 14

Which of the following best explains why cellulose cannot be digested by human enzymes, while starch can?

Accepted Answer

Cellulose has a different glycosidic linkage (beta) than starch (alpha), making it incompatible with human enzymes.

Question 15

Which of the following processes requires energy input from the cell (usually in the form of ATP)?

Accepted Answer

Active transport

Question 16

A membrane shows some permeability to glucose. If the proportion of unsaturated phospholipids in the membrane is increased, what will happen to the membrane’s permeability to glucose?

Accepted Answer

Permeability to glucose will increase.

Question 17

Which of the following increases the strength of hydrophobic interactions in lipid bilayers, making them less permeable to polar molecules?

Accepted Answer

Increasing the length of the hydrocarbon chains

Question 18

Which of the following best describes the process by which white blood cells engulf bacteria?

Accepted Answer

Phagocytosis

Question 19

Which of the following statements about the formation of a phosphodiester bond in nucleic acids is correct?

Accepted Answer

A phosphodiester bond forms between the 3' hydroxyl group of one nucleotide and the 5' phosphate of another nucleotide by condensation.

Question 20

Which of the following best describes the difference between facilitated diffusion and active transport?

Accepted Answer

Active transport requires cellular energy (often from ATP hydrolysis), while facilitated diffusion does not.

General Biology Exam I Study Guide: Foundations, Chemistry, and Macromolecules

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