Q: Which equation correctly represents the breakdown of lactose in the human digestive system?

$$\text{Lactose} \xrightarrow{\text{lactase}} \text{Glucose} + \text{Galactose}$$

Question 1

Which of the following best explains why water has a high surface tension?

Accepted Answer

Hydrogen bonds between water molecules result in cohesion, allowing water to resist external force.

Question 2

A patient is prescribed antibiotics for a bacterial infection. After several treatments, the infection persists. Which biological concept best explains this scenario?

Accepted Answer

The bacteria have developed resistance due to mutations, making them insensitive to the antibiotic.

Question 3

Which of the following is a correct description of a covalent bond?

Accepted Answer

A bond where electrons are shared between atoms, often resulting in partial charges due to electronegativity differences.

Question 4

Why does ice float on liquid water?

Accepted Answer

Hydrogen bonds in ice keep water molecules farther apart, making ice less dense than liquid water.

Question 5

Which equation correctly represents the breakdown of lactose in the human digestive system?

Accepted Answer

$$	ext{Lactose} \xrightarrow{	ext{lactase}} 	ext{Glucose} + 	ext{Galactose}$$

Question 6

A population in western Africa has high levels of lactose tolerance. What is the most likely genetic explanation for this?

Accepted Answer

A random mutation allowed the lactose gene to remain active, enabling adults to digest milk.

Question 7

Which property of water is most important for moderating Earth's climate?

Accepted Answer

Water’s high specific heat due to hydrogen bonding, allowing it to resist temperature changes.

Question 8

Which of the following best describes the concept of electronegativity?

Accepted Answer

The attraction of an atom for shared electrons in a chemical bond.

Question 9

A scientist is designing an experiment to test the effect of antioxidants on heart transplant patients. Which of the following is the most important feature to include for scientific validity?

Accepted Answer

A control group that does not receive antioxidants.

Question 10

Which of the following is NOT a function of hydrogen bonds in water?

Accepted Answer

Allowing water to dissolve nonpolar substances.

Question 11

Which of the following best explains why $$	ext{H}_2	ext{O} is $$polar?

Accepted Answer

Oxygen has a higher electronegativity than hydrogen, causing shared electrons to be pulled closer to oxygen.

Question 12

Which of the following is a polysaccharide?

Accepted Answer

Starch

Question 13

Which of the following statements about autism is supported by current scientific evidence?

Accepted Answer

Autism is associated with over 100 genes and is influenced by both genetic and environmental factors.

Question 14

Which of the following best describes the role of a control group in a scientific experiment?

Accepted Answer

It provides a baseline for comparison to determine the effect of the experimental variable.

Question 15

Which of the following is a correct statement about lactose intolerance?

Accepted Answer

Lactose is not broken down in the small intestine, leading to fermentation by bacteria and gas production.

Question 16

Which of the following best explains why salt disrupts hydrogen bonding in water?

Accepted Answer

Salt ions interfere with the attraction between water molecules, reducing the number of hydrogen bonds.

Question 17

Which of the following is an example of mimicry in biology?

Accepted Answer

A harmless species resembling a harmful species to avoid predation.

Question 18

Which of the following is true about the atomic number?

Accepted Answer

It is equal to the number of protons in the nucleus of an atom.

Question 19

Which of the following best describes the effect of epigenetics on autism risk?

Accepted Answer

Environmental factors can alter the structure and function of DNA, influencing gene expression related to autism.

General Biology: Antibiotic Resistance, Scientific Method, Vaccines & Autism, Chemistry of Life, and Lactose Tolerance

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