Chapter 4

Question 1

What is cytology?

Answer 1

The study of cells.

Question 2

What is microscopy?

Answer 2

Using a microscope to view small-scale structures

Question 3

What are the two types of microscopes used to study cells?

Answer 3

Light Microscope (LM) and Electron Microscope (EM).

Question 4

What is the difference between a Light Microscope and an Electron Microscope?

Answer 4

A Light Microscope uses light to form a 2D image, while an Electron Microscope uses electron beams for higher magnification and resolution.

Question 5

What is the function of a Transmission Electron Microscope (TEM)?

Answer 5

It directs an electron beam through thin-cut sections, producing a 2D image of internal cell structures.

Question 6

How does a Scanning Electron Microscope (SEM) work?

Answer 6

It directs an electron beam across the surface of a specimen, producing a 3D image.

Question 7

What are the three main structural features of a cell?

Answer 7

Plasma membrane, cytoplasm, and nucleus.

Question 8

What is the function of the plasma membrane?

Answer 8

It forms the outer barrier of the cell and regulates movement of substances in and out.

Question 9

What extensions of the plasma membrane help in movement or absorption?

Answer 9

Cilia, flagella, and microvilli.

Question 10

What is the nucleus and what does it contain?

Answer 10

It is the largest cell structure that contains DNA and is enclosed by a nuclear envelope.

Question 11

What are the components of the cytoplasm?

Answer 11

Cytosol, organelles, and inclusions.

Question 12

What is cytosol?

Answer 12

intracellular fluid, contains dissolved macromolecules and ions

Question 13

What are the two main types of organelles?

Answer 13

Membrane-bound and non-membrane-bound organelles.

Question 14

What is a membrane-bound organelle?

Answer 14

enclosed by a membrane, separates contents from cytosol

Question 15

What is a non-membrane-bound organelle?

Answer 15

not enclosed within a membrane, composed of protein

Question 16

Name five membrane-bound organelles.

Answer 16

Endoplasmic Reticulum (ER), Golgi apparatus, lysosomes, peroxisomes, and mitochondria.

Question 17

Name four non-membrane-bound organelles.

Answer 17

Ribosomes, cytoskeleton, centrosome, and proteasomes.

Question 18

What is the function of the rough ER?

Answer 18

Protein production and transport.

Question 19

What are the three main types of lipids in the plasma membrane?

Answer 19

Phospholipids, cholesterol, and glycolipids.

Question 20

What is the structure of a phospholipid?

Answer 20

A hydrophilic (polar) head and two hydrophobic (nonpolar) tails.

Question 21

What is the function of cholesterol in the plasma membrane?

Answer 21

Strengthens the membrane and stabilizes it against temperature changes.

Question 22

What do glycolipids do?

Answer 22

Help form the glycocalyx, which is important for cell recognition.

Question 23

What are the two main types of membrane proteins?

Answer 23

Integral and peripheral proteins.

Question 24

What is the role of transport proteins?

Answer 24

To regulate the movement of substances across the membrane

Question 25

What are cell surface receptors?

Answer 25

Proteins that bind specific molecules (ligands) to trigger cellular responses.

Question 26

What are identity markers?

Answer 26

Proteins that help the immune system recognize normal cells from foreign ones.

Question 27

What are the two main categories of membrane transport?

Answer 27

Passive and active transport.

Question 28

What is the difference between passive and active transport?

Answer 28

Passive transport requires no energy (moves down the concentration gradient), while active transport requires energy (moves against the concentration gradient).

Question 29

What are the two types of passive transport?

Answer 29

Diffusion and osmosis.

Question 30

What is simple diffusion?

Answer 30

The movement of small, nonpolar molecules directly across the phospholipid bilayer.

Question 31

What is facilitated diffusion?

Answer 31

The transport of charged or polar molecules through protein channels or carriers.

Question 32

What is osmosis?

Answer 32

The passive movement of water through a selectively permeable membrane.

Question 33

What happens in a hypotonic solution?

Answer 33

Water enters the cell, possibly causing it to burst (lysis).

Question 34

What happens in a hypertonic solution?

Answer 34

Water leaves the cell, causing it to shrink (crenation).

Question 35

What is primary active transport?

Answer 35

Uses ATP to move substances against their concentration gradient.

Question 36

What is secondary active transport?

Answer 36

Uses the movement of one substance down its gradient to power the movement of another against its gradient.

Question 37

What is endocytosis?

Answer 37

The process of bringing substances into the cell via vesicles.

Question 38

What are the three types of endocytosis?

Answer 38

Phagocytosis (cell eating), pinocytosis (cell drinking), and receptor-mediated endocytosis.

Question 39

What are the three types of membrane junctions?

Answer 39

Tight junctions, desmosomes, and gap junctions.

Question 40

What is the function of tight junctions?

Answer 40

Prevent substances from passing between cells.

Question 41

What is the function of desmosomes?

Answer 41

Provide mechanical strength by anchoring cells together.

Question 42

What is the function of gap junctions?

Answer 42

Allow direct communication between cells through small tunnels.

Question 43

What are the functions of the rough and smooth ER?

Answer 43

Rough ER: Protein synthesis and transport. Smooth ER: Lipid synthesis and detoxification.

Question 44

What does the Golgi apparatus do?

Answer 44

Modifies, sorts, and packages proteins for secretion or use in the cell.

Question 45

What are lysosomes?

Answer 45

Small sacs containing digestive enzymes that break down waste.

Question 46

What are peroxisomes?

Answer 46

Organelles that detoxify substances and perform lipid metabolism.

Question 47

What is the main function of mitochondria?

Answer 47

Produces ATP through aerobic respiration ("powerhouse of the cell").

Question 48

What are ribosomes?

Answer 48

Structures that synthesize proteins.

Question 49

What is the centrosome function?

Answer 49

Organizes microtubules and plays a role in cell division.

Question 50

What do proteasomes do?

Answer 50

Break down damaged or unnecessary proteins.

Question 51

What are the three components of the cytoskeleton?

Answer 51

Microfilaments – Smallest, provide cell shape. Intermediate filaments – Provide mechanical support. Microtubules – Largest, involved in cell transport and division.

Question 52

hat is the function of flagella?

Answer 52

Propels the entire cell (e.g., sperm).