FREE HESI Critical Thinking Questions and Answers

Question 1

A student observes a plant bending toward a light source. What is the best explanation for this behavior?

Accepted Answer

Phototropism

Answer

Phototropism is the growth response of a plant in response to a light stimulus. When a plant bends toward a light source, it is exhibiting positive phototropism, a mechanism that helps it maximize light absorption for photosynthesis.

Question 2

If a cell is placed in a hypertonic solution, what will most likely happen to the cell?

Accepted Answer

The cell will shrink

Answer

A hypertonic solution has a higher solute concentration outside the cell than inside. Due to osmosis, water will move from an area of higher water concentration (inside the cell) to an area of lower water concentration (outside the cell) to equalize the solute concentration, causing the cell to lose water and shrink.

Question 3

Which conclusion is best supported by the discovery of fossils with similar bone structures in different species?

Accepted Answer

They share a common ancestor

Answer

The discovery of fossils with similar bone structures (homologous structures) in different species provides strong evidence for common ancestry. These shared anatomical features suggest that these species evolved from a common ancestor, with modifications occurring over time due to adaptation to different environments.

Question 4

Why is it important to have a control group in a biological experiment?

Accepted Answer

To serve as a baseline for comparison

Answer

A control group in a biological experiment is essential because it provides a baseline for comparison. This group does not receive the experimental treatment or manipulation, allowing researchers to isolate the effect of the independent variable and determine if observed changes in the experimental group are truly due to the treatment.

Question 5

A scientist finds that changing the pH of a solution stops an enzyme from working. What is the most logical explanation?

Accepted Answer

The enzyme denatured due to pH change

Answer

Enzymes are highly sensitive to changes in environmental conditions like pH and temperature because these factors can alter their specific three-dimensional structure, particularly the active site. When the pH changes drastically, the enzyme can denature, meaning its shape is altered, rendering it unable to bind to its substrate and function effectively.

HESI (ATI) Practice Test

HESI (ATI) Practice Test

FREE HESI Critical Thinking Questions and Answers