1.1 and 1.2

Question 1

What are the capabilities of unicellular organisms?

Answer 1

• Independent existence
• Performing essential functions of life

Question 2

Who was the first person to see and describe a live cell?

Answer 2

Anton Von Leeuwenhoek

Question 3

Who discovered the nucleus?

Answer 3

Robert Brown

Question 4

How did the invention and improvement of the microscope contribute to our understanding of cells?

Answer 4

• Revealed all the structural details of the cell
• Electron microscope provided even higher resolution images

Question 5

Who examined plants and discovered that all plants are composed of different kinds of cells?

Answer 5

Matthias Schleiden

Question 6

What did Theodore Schwann discover about cells?

Answer 6

He discovered that cells have a thin outer layer called the plasma membrane.

Question 7

Q: What did Schwann conclude about plant cells?

Answer 7

He concluded that plant cells have a unique characteristic: the presence of a cell wall.

Question 8

Q: What hypothesis did Schwann propose based on his observations?

Answer 8

He proposed that the bodies of animals and plants are composed of cells and products of cells.

Question 9

Q: Who formulated the cell theory?

Answer 9

Matthias Schleiden and Theodore Schwann together formulated the cell theory.

Question 10

Q: Who explained how new cells are formed?

Answer 10

Rudolf Virchow explained that cells divide and new cells are formed from pre-existing cells.

Question 11

Q: What are the two main principles of the modern cell theory?

Answer 11

• All living organisms are composed of cells and their products.
• Cells arise from pre-existing cells.

Question 12

Q: What is the dense membrane-bound structure inside a cell that contains chromosomes?

Answer 12

Nucleus

Question 13

What is the semi-fluid matrix occupying the volume of a cell called?

Answer 13

Cytoplasm

Question 14

Q: What is the outer boundary of a plant cell called?

Answer 14

Cell wall

Question 15

Q: What is the outer membrane of a human cheek cell called?

Answer 15

Cell membrane

Question 16

Q: What are the non-membrane bound organelles found in all cells?

Answer 16

Ribosomes

Question 17

Q: What is the non-membrane bound organelle found in animal cells that helps in cell division?

Answer 17

Centrosome

Question 18

Q: How do cells vary in terms of size and shape?

Answer 18

Cells can vary greatly in size, ranging from the smallest cells like Mycoplasmas to larger cells like bacteria or the ostrich egg.

They also vary in shape, which can be disc-like, polygonal, columnar, cuboid, thread-like, or irregular.

Question 19

Q: What are some examples of prokaryotic cells?

Answer 19

Bacteria, blue-green algae, mycoplasma, and PPLO (Pleuro Pneumonia Like Organisms).

Question 20

How do prokaryotic cells differ from eukaryotic cells in terms of size and multiplication?

Answer 20

Prokaryotic cells are generally smaller and multiply more rapidly than eukaryotic cells.

Question 21

Q: What are the four basic shapes of bacteria?

Answer 21

A: The four basic shapes of bacteria are bacillus (rod-like), coccus (spherical), vibrio (comma-shaped), and spirillum (spiral).

Question 22

Q: What are some common features of prokaryotic cells?

Answer 22

A: Prokaryotic cells have a cell wall surrounding the cell membrane, a fluid-filled cytoplasm, and genetic material that is not enclosed by a nuclear membrane. They may also contain small circular DNA called plasmids, which can confer unique traits like antibiotic resistance.

Question 23

Q: Are there any organelles in prokaryotic cells?

Answer 23

A: No, prokaryotic cells do not have organelles like eukaryotic cells, except for ribosomes.

Question 24

Q: What is a unique characteristic of prokaryotic cells?

Answer 24

A: Prokaryotic cells have a specialized form of cell membrane called mesosome, which consists of infoldings of the cell membrane.

Question 25

Q: How is the genetic material of prokaryotic cells different from eukaryotic cells?

Answer 25

A: In prokaryotic cells, the genetic material is naked and not enveloped by a nuclear membrane, whereas eukaryotic cells have a nucleus that contains the genetic material.

Question 26

Q: What are plasmids and what role do they play in prokaryotic cells?

Answer 26

A: Plasmids are small circular DNA molecules found in many bacteria. They carry additional genetic information and can confer unique traits to the bacteria, such as antibiotic resistance.

Question 27

Q: What is the structure of the cell envelope in prokaryotic cells?

Answer 27

A: The cell envelope in prokaryotic cells consists of three layers: glycocalyx, cell wall, and plasma membrane.

Question 28

Q: How are bacteria classified based on their response to the Gram staining procedure?

Answer 28

A: Bacteria are classified into two groups: Gram-positive bacteria, which take up the Gram stain, and Gram-negative bacteria, which do not.

Question 29

Q: What is the role of glycocalyx in bacteria?

Answer 29

A: Glycocalyx can be a loose sheath called the slime layer or a thick and tough capsule. It helps protect the cell and may be involved in attachment to surfaces.

Question 30

Q: What is the function of the cell wall in bacteria?

Answer 30

A: The cell wall determines the shape of the cell and provides structural support to prevent the bacterium from bursting or collapsing.

Question 31

Q: How is the plasma membrane of prokaryotic cells similar to that of eukaryotic cells?

Answer 31

A: The plasma membrane in prokaryotic cells is selectively permeable and interacts with the outside world, similar to the plasma membrane in eukaryotic cells.

Question 32

Q: What is a mesosome in prokaryotic cells?

Answer 32

A: A mesosome is a specialized membranous structure formed by extensions of the plasma membrane into the cell. It plays roles in cell wall formation, DNA replication, and other cellular processes.

Question 33

Q: What are flagella in bacterial cells and what is their function?

Answer 33

A: Flagella are thin filamentous extensions from the cell wall that allow bacteria to move. They help the bacteria navigate their environment.

Question 34

Q: What are pili and fimbriae in bacterial cells?

Answer 34

A: Pili are elongated tubular structures made of a special protein, while fimbriae are small bristle-like fibers. They may help bacteria attach to surfaces or host tissues.

Question 35

Q: Where are ribosomes located in prokaryotic cells and what is their function?

Answer 35

A: Ribosomes are associated with the plasma membrane of prokaryotic cells. They are responsible for protein synthesis, translating mRNA into proteins.

Question 36

Q: What are the two subunits that make up prokaryotic ribosomes and their sizes?

Answer 36

A: Prokaryotic ribosomes are made up of two subunits: 50S and 30S. When these subunits are together, they form 70S prokaryotic ribosomes.

Question 37

Q: What is the function of polyribosomes or polysomes?

Answer 37

A: Polyribosomes or polysomes are chains of several ribosomes attached to a single mRNA. They work together to translate the mRNA into proteins.

Question 38

Q: How do prokaryotic cells store reserve materials?

Answer 38

A: Reserve materials in prokaryotic cells are stored as inclusion bodies in the cytoplasm. These inclusion bodies are not bound by a membrane and can include substances like phosphate granules, cyanophycean granules, and glycogen granules.

Question 39

Q: What are gas vacuoles and in which bacteria are they found?

Answer 39

A: Gas vacuoles are present in certain types of bacteria, specifically blue-green and purple and green photosynthetic bacteria.