Question 1

Which of the following best describes the primary function of the plasma membrane in maintaining cellular homeostasis?

Accepted Answer

It regulates the movement of molecules into and out of the cell, allowing selective transport to maintain internal balance.

Question 2

A scientist is studying a protein that helps move glucose across the cell membrane. Which type of membrane transport is most likely involved, and what is the key feature of this process?

Accepted Answer

Facilitated diffusion; glucose moves down its concentration gradient via a specific transport protein.

Question 3

Which of the following equations correctly represents the process of cellular respiration?

Accepted Answer

$$C_6H_{12}O_6$ + 6O_2 \rightarrow 6CO_2 + 6H_2O + ATP$$

Question 4

A patient is diagnosed with a genetic disorder that affects the structure of their lysosomal enzymes. Which cellular process is most likely to be impaired?

Accepted Answer

Breakdown of macromolecules and cellular waste

Question 5

During an experiment, a student observes that a plant cell placed in a hypertonic solution shrinks. Which process is responsible for this observation?

Accepted Answer

Osmosis, causing water to move out of the cell

Question 6

Which of the following best explains why DNA replication is considered semi-conservative?

Accepted Answer

Each new DNA molecule consists of one original strand and one new strand.

Question 7

A mutation occurs in the gene encoding a membrane protein responsible for active transport of sodium ions. What is the most likely consequence for the cell?

Accepted Answer

The cell will lose its ability to maintain proper ion gradients, affecting nerve impulse transmission.

Question 8

Which of the following statements about Mendelian inheritance is correct?

Accepted Answer

A dominant allele will mask the expression of a recessive allele in a heterozygote.

Question 9

In a laboratory experiment, students are asked to model the transfer of genetic information from DNA to protein. Which sequence of events correctly describes this process?

Accepted Answer

Transcription $$\rightarrow$$ Translation

Question 10

A researcher is studying the effect of a new drug on the rate of enzyme-catalyzed reactions. Which variable should be kept constant to ensure valid results?

Accepted Answer

Temperature at which the reaction occurs

Question 11

Which of the following best describes the role of ribosomes in a eukaryotic cell?

Accepted Answer

They are the site of protein synthesis, translating mRNA into polypeptides.

Question 12

A cell is observed to have a high number of mitochondria. Which hypothesis best explains this observation?

Accepted Answer

The cell requires large amounts of energy for its functions.

Question 13

Which of the following is a correct statement about the structure of biological polymers?

Accepted Answer

Carbohydrates are composed of monosaccharides joined by glycosidic bonds.

Question 14

A virus infects a bacterial cell and uses the host's machinery to produce new viral particles. Which term best describes this process?

Accepted Answer

Lytic cycle

Question 15

Which of the following best explains the importance of biotechnology in modern medicine?

Accepted Answer

It enables the manipulation of genetic material to develop treatments such as gene therapy and recombinant insulin.

Question 16

A student is asked to predict the outcome of a cross between two heterozygous pea plants for a single gene (Tt x Tt). What is the expected phenotypic ratio in the offspring?

Accepted Answer

3:1

Question 17

Which of the following best describes the flow of genetic information according to the central dogma of molecular biology?

Accepted Answer

DNA $$\rightarrow$$ RNA $$\rightarrow$$ Protein

Question 18

In a laboratory simulation, students are asked to measure the rate of photosynthesis in spinach leaves. Which variable would most directly affect the rate of photosynthesis?

Accepted Answer

Intensity of light provided to the leaves

Question 19

A geneticist is studying the inheritance of a rare disease that appears only when both parents are carriers but do not show symptoms. Which pattern of inheritance does this most likely represent?

Accepted Answer

Autosomal recessive

BIO 251 Biology I with Lab – Course Overview and Study Guide

Study Guide - Practice Questions

Study Guide - Flashcards