Question 1

A patient is experiencing difficulty with gas exchange in the lungs due to thickening of the simple squamous epithelium. Which physiological process is most directly impaired, and why?

Accepted Answer

Diffusion, because increased thickness reduces the rate of gas movement across the membrane as described by Fick's Law: $$ J = -D \frac{\Delta C}{\Delta x} $$

Question 2

Which of the following best describes the role of negative feedback in homeostasis?

Accepted Answer

It opposes deviations from a set point, reducing the original stimulus to maintain stability.

Question 3

A researcher adds more substrate to an enzyme-catalyzed reaction. According to the Michaelis-Menten equation $$ v = \frac{V_{max}[S]}{K_m + [S]} $$, what will happen to the reaction rate as substrate concentration increases?

Accepted Answer

The reaction rate will increase and eventually approach a maximum velocity ($$ V_{max} ).$$

Question 4

Which of the following molecules is most likely to be hydrophobic and able to cross the plasma membrane without assistance?

Accepted Answer

Oxygen ($$ O_2$ )$$

Question 5

A patient has a genetic mutation that alters the structure of their collagen fibers. Which tissue function is most likely to be affected?

Accepted Answer

Structural support in connective tissue

Question 6

Which of the following best explains why phospholipids form bilayers in water?

Accepted Answer

Their hydrophobic tails avoid water while hydrophilic heads interact with water, minimizing free energy.

Question 7

During vigorous exercise, muscle cells increase their uptake of glucose. Which membrane transport process is primarily responsible for this increased uptake?

Accepted Answer

Facilitated diffusion via glucose transporters

Question 8

Which of the following best distinguishes an anabolic reaction from a catabolic reaction?

Accepted Answer

Anabolic reactions require energy input to build complex molecules, while catabolic reactions release energy by breaking down molecules.

Question 9

A solution contains $$ 0.1 	ext{ mol/L}  of$$ $$ NaCl $$ and $$ 0.1 	ext{ mol/L}  of$$ $$ $$CaCl_2$$ . $$Which solution has a higher osmolarity, and why?

Accepted Answer

$$ $$CaCl_2$$ $$, because it dissociates into three ions per formula unit, increasing osmolarity: $$ 	ext{Osmolarity} = 	ext{Molarity} 	imes 	ext{number of particles} $$

Question 10

Which of the following best describes the function of the rough endoplasmic reticulum (RER)?

Accepted Answer

Protein synthesis and modification due to ribosomes on its surface

Question 11

A patient is diagnosed with fibrosis in the liver, leading to excessive deposition of extracellular matrix. Which consequence is most likely?

Accepted Answer

Loss of tissue function due to impaired diffusion and cell signaling

Question 12

Which of the following best explains why enzymes lower the activation energy of a reaction?

Accepted Answer

They provide an alternative reaction pathway with a lower activation energy ($$ E_a ).$$

Question 13

Which of the following is a key difference between epithelial and connective tissue?

Accepted Answer

Epithelial tissue is avascular and forms protective barriers, while connective tissue is vascular and provides support.

Question 14

A cell is placed in a hypertonic solution. What will happen to the cell, and why?

Accepted Answer

It will shrink, because water leaves the cell to balance solute concentration.

Question 15

Which of the following best describes the function of fibroblasts in connective tissue?

Accepted Answer

They secrete collagen and other extracellular matrix components.

Question 16

Which of the following best explains why the genetic code is considered 'degenerate'?

Accepted Answer

Multiple codons can code for the same amino acid.

Question 17

A patient is unable to produce sufficient ATP in their cells. Which organelle is most likely malfunctioning?

Accepted Answer

Mitochondria

Question 18

Which of the following best describes the difference between a covalent and an ionic bond?

Accepted Answer

Covalent bonds involve sharing electrons, while ionic bonds involve transfer of electrons.

Question 19

Which of the following is a function of membrane carbohydrates?

Accepted Answer

Cell recognition and signaling

Question 20

A patient has a mutation that prevents the formation of tight junctions in epithelial tissue. Which of the following is a likely consequence?

Accepted Answer

Increased leakage of substances between cells

Anatomy & Physiology: Foundational Concepts, Chemistry, Cell Structure, and Histology

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