biology chp 4

Question 1

microscopy

Answer 1

phenomenon in which an object is seen under the microscope, which is not visible to the naked eyes.

Question 2

cell fractionation

Answer 2

A combination of methods used to separate cell components and organelles based on size and density.

Question 3

Who first discovered the cell, and in what year?

Answer 3

Robert Hooke in 1665.

Question 4

What are the three main principles of the cell theory?

Answer 4

1. All living organisms are composed of one or more cells.
2. The cell is the basic unit of life.
3. All cells arise from pre-existing cells.

Question 5

Name two scientists who contributed to the development of cell theory.

Answer 5

Matthias Schleiden (1838) and Theodor Schwann (1839).

Question 6

What is the difference between magnification and resolution in microscopy?:

Answer 6

Magnification refers to how much larger an image appears compared to its actual size.
Resolution is the ability to distinguish two close objects as separate entities.

Question 7

What does centrifugation help achieve in cell biology?

Answer 7

Centrifugation separates cellular components based on their size and density, allowing for the isolation of organelles.

Question 7

What model explains the structure of the cell membrane?

Answer 7

The Fluid Mosaic Model, which describes the membrane as a dynamic, flexible layer made of lipids and proteins.

Question 8

What is the primary function of mitochondria?

Answer 8

Mitochondria are responsible for ATP production through cellular respiration, providing energy to the cell.

Question 9

Where are ribosomes found, and what is their function?

Answer 9

Ribosomes can be found free in the cytoplasm or attached to the rough ER. They are responsible for protein synthesis.

Question 10

What is the function of lysosomes?

Answer 10

Lysosomes contain digestive enzymes that break down waste materials and cellular debris.

Question 11

Name two organelles found in plant cells but not in animal cells.

Answer 11

Chloroplasts and cell wall.

Question 12

What is the primary difference between prokaryotic and eukaryotic cells?

Answer 12

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

Question 13

What is the function of the rough and smooth ER?

Answer 13

Rough ER: Synthesizes proteins.
Smooth ER: Synthesizes lipids and detoxifies substances.

Question 14

What is the role of the Golgi apparatus?

Answer 14

The Golgi apparatus modifies, sorts, and packages proteins and lipids for transport.

Question 15

What is the function of the nucleus?

Answer 15

The nucleus stores genetic material (DNA) and controls cellular activities like growth, metabolism, and reproduction.

Question 16

What is the function of chloroplasts?

Answer 16

Chloroplasts carry out photosynthesis, converting sunlight into chemical energy in plants.

Question 17

What is the function of the plant cell wall?

Answer 17

The cell wall provides structural support and protection to plant cells.

Question 18

What happens when lysosomes malfunction, and name a related disease.

Answer 18

Malfunctioning lysosomes can lead to storage diseases, such as Tay-Sachs disease, where waste accumulates inside cells.

Question 19

What is the role of the cytoskeleton in the cell?

Answer 19

The cytoskeleton provides structural support, facilitates cell movement, and aids in transport of materials within the cell.