Cells and Microscopes, The Bacterial cell wall and Gram staining.

Question 1

What is the function of a microscope in cell biology?

Answer 1

Microscopes are used to magnify small objects, such as cells, that are too small to be seen by the naked eye, allowing scientists to study their structure and function.

Question 2

What is the difference between light microscopes and electron microscopes?

Answer 2

Light microscopes use visible light and lenses to magnify specimens up to about 1000x, while electron microscopes use beams of electrons for much higher magnification and resolution, allowing for detailed views of cell structures.

Question 3

What is cell theory?

Answer 3

Cell theory states that all living things are made up of cells, the cell is the basic unit of life, and all cells arise from pre-existing cells.

Question 4

What are the main components of a plant cell visible under a light microscope?

Answer 4

The cell wall, cell membrane, nucleus, chloroplasts, vacuole, and cytoplasm.

Question 5

What are the advantages of using an electron microscope?

Answer 5

Higher resolution and magnification compared to light microscopes, allowing visualization of detailed structures within cells, such as organelles and viruses.

Question 6

What is magnification in microscopy?

Answer 6

Magnification is how many times larger an object appears compared to its actual size.

Question 7

How do you calculate magnification?

Answer 7

Magnification = Size of the image / Actual size of the object.

Question 8

What is resolution in microscopy?

Answer 8

Resolution is the ability of a microscope to distinguish two objects as separate entities. Higher resolution provides clearer and more detailed images.

Question 9

What are the limitations of light microscopes?

Answer 9

Limited magnification and resolution compared to electron microscopes, and they cannot visualize structures smaller than about 200 nanometers.

Question 10

What are the two types of electron microscopes?

Answer 10

Transmission Electron Microscope (TEM) and Scanning Electron Microscope (SEM).

Question 11

What is the structure of a bacterial cell wall?

Answer 11

The bacterial cell wall is primarily made of peptidoglycan, a mesh-like polymer composed of sugars and amino acids, providing structural support and protection.

Question 12

What is the role of the bacterial cell wall?

Answer 12

The cell wall provides structural support, maintains the shape of the bacterium, and protects it from osmotic pressure.

Question 13

What is the difference between Gram-positive and Gram-negative bacterial cell walls?

Answer 13

Gram-positive bacteria have a thick peptidoglycan layer and no outer membrane, while Gram-negative bacteria have a thin peptidoglycan layer and an outer membrane containing lipopolysaccharides.

Question 14

Why are Gram-negative bacteria generally more resistant to antibiotics?

Answer 14

he outer membrane of Gram-negative bacteria acts as a barrier to many antibiotics, making them more resistant to treatments compared to Gram-positive bacteria.

Question 15

What is peptidoglycan?

Answer 15

Peptidoglycan is a polymer that makes up the bacterial cell wall, providing rigidity and protection from environmental stress.

Question 16

How does the bacterial cell wall affect antibiotic treatment?

Answer 16

Antibiotics like penicillin target the peptidoglycan in bacterial cell walls, preventing the bacteria from maintaining their structure and causing them to die.

Question 17

What is the function of the bacterial outer membrane in Gram-negative bacteria?

Answer 17

The outer membrane provides protection against harmful substances, such as antibiotics, and contains proteins and lipopolysaccharides that contribute to the bacteria’s defense mechanisms.

Question 18

How do bacteria without cell walls survive?

Answer 18

Some bacteria, like mycoplasmas, lack a cell wall but survive by having a stronger cell membrane that is resistant to osmotic pressure changes.Some bacteria, like mycoplasmas, lack a cell wall but survive by having a stronger cell membrane that is resistant to osmotic pressure changes.

Question 19

What is the formula for magnification?

Answer 19

Magnification=
Actualsizeofobject / Imagesize

Question 20

What are plasmids?

Answer 20

Plasmids are small, circular DNA molecules found in bacterial cells, separate from the chromosomal DNA, often carrying antibiotic resistance genes.

Question 21

What is a flagellum?

Answer 21

A flagellum is a tail-like structure that allows bacteria to move.

Question 22

What is the purpose of the cytoplasm in bacterial cells?

Answer 22

The cytoplasm is the gel-like substance where metabolic activities occur and it contains enzymes and ribosomes for protein synthesis.

Question 23

What is the size range of most bacterial cells?

Answer 23

Bacterial cells typically range from 0.2 to 2 micrometers in size.

Question 24

How do electron microscopes benefit bacterial cell study?

Answer 24

Electron microscopes offer much higher resolution than light microscopes, allowing scientists to see detailed structures of bacterial cells like ribosomes and cell membranes.

Question 25

What is the function of the bacterial cell wall?

Answer 25

The bacterial cell wall provides structural support and protection. It is made of peptidoglycan in most bacteria.

Question 26

What is the main structural difference between bacterial and eukaryotic cells?

Answer 26

Bacterial cells lack a true nucleus and membrane-bound organelles, while eukaryotic cells have both.