Water moves toward higher solute concentration: $$\text{Net flow} \propto (C_{solute, outside} - C_{solute, inside})$$

$$3 \text{Na}^+_{in} \rightarrow 3 \text{Na}^+_{out}$$ and $$2 \text{K}^+_{out} \rightarrow 2 \text{K}^+_{in}$$, using 1 ATP$

Question 1

Which component of the plasma membrane is primarily responsible for maintaining membrane fluidity at varying temperatures?

Accepted Answer

Cholesterol

Question 2

A red blood cell is placed in a hypotonic solution. What is the most likely outcome for the cell?

Accepted Answer

It will swell and possibly burst due to water influx (cytolysis).

Question 3

Which of the following best describes the 'Selective Permeable Fluid Mosaic Model' of the plasma membrane?

Accepted Answer

A dynamic combination of lipids, proteins, and carbohydrates that allows selective movement of substances.

Question 4

Which type of membrane transport requires energy in the form of ATP and moves substances against their concentration gradient?

Accepted Answer

Active transport

Question 5

What is the main function of aquaporins in the plasma membrane?

Accepted Answer

Allow water molecules to rapidly cross the membrane

Question 6

Which organelle is responsible for packaging and directing proteins to their proper destinations within or outside the cell?

Accepted Answer

Golgi apparatus

Question 7

During which phase of the cell cycle does DNA replication occur?

Accepted Answer

S phase

Question 8

Which cytoskeletal element is primarily involved in muscle contraction?

Accepted Answer

Actin filaments

Question 9

A cell is exposed to a hypertonic solution. Using the concept of osmosis, which equation best describes the net movement of water?

Accepted Answer

Water moves toward higher solute concentration: $$	ext{Net flow} \propto (C_{solute, outside} - C_{solute, inside})$$

Question 10

Which process describes the synthesis of RNA from a DNA template?

Accepted Answer

Transcription

Question 11

Which of the following is TRUE regarding facilitated diffusion?

Accepted Answer

It uses channel or carrier proteins to move molecules down their concentration gradient.

Question 12

Which organelle is abundant in liver cells due to its role in detoxification?

Accepted Answer

Smooth endoplasmic reticulum

Question 13

What is the primary function of lysosomes in a cell?

Accepted Answer

Digestion and breakdown of cellular waste

Question 14

Which phase of mitosis is characterized by the alignment of chromosomes at the cell's equatorial plate?

Accepted Answer

Metaphase

Question 15

Which of the following best explains why insulin is unable to stimulate glucose uptake in Type 2 Diabetes?

Accepted Answer

Liver and muscle cells down-regulate insulin receptors, preventing glucose channel activation.

Question 16

Which equation best represents the movement of sodium ions by the Na+/K+ pump during active transport?

Accepted Answer

$$3 	ext{Na}^+_{in} ightarrow 3 	ext{Na}^+_{out}$$ and $$2 	ext{K}^+_{out} ightarrow 2 	ext{K}^+_{in}$$, using 1 ATP$

Question 17

Which cytoskeletal structure is essential for the movement of cilia and flagella?

Accepted Answer

Microtubules

Question 18

During which phase of mitosis do sister chromatids separate and move toward opposite poles?

Accepted Answer

Anaphase

Question 19

Which process is responsible for programmed cell death and is crucial for development and preventing tumor growth?

Accepted Answer

Apoptosis

Question 20

Which of the following best describes the role of the Golgi apparatus in protein synthesis?

Accepted Answer

It modifies, sorts, and packages proteins for delivery to their destinations.

Cell Biology: Structure and Function (McKinley Chapter 4) - Study Notes

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