Cells

Question 1

What is the function of the nucleus?

Answer 1

• Stores DNA as chromatin

- Coordinates cell’s activities, such as growth, protein synthesis and reproduction.

Question 2

What is the function of the plasma membrane?

Answer 2

• Surrounds cell to provide a physical barrier to control exit and entry of substances
• Allows communication between cells
• Detects and responds to environmental changes

Question 3

What is the function of the nucleolus?

Answer 3

• Produces rRNA and combines it with other proteins

- Releases them through nucleur envelope

Question 4

What is the function of the Rough Endoplasmic Reticulum?

Answer 4

Ribosomes on the RER synthesis and package proteins into vesicles

Question 5

What is the function of the Golgi apparatus?

Answer 5

Modifies proteins then repackages them into vesicles.

Question 6

What is the function of lysosomes?

Answer 6

Break down cellular waste, such as dead/damaged organelles and pathogens.

Question 7

What is the function of the Smooth Endoplasmic Reticulum?

Answer 7

• Contains enzymes which helps with the creation of important lipids
• Stores ions and helps cells detox

Question 8

What is the function of ribosomes?

Answer 8

Site for protein synthesis to occur

Question 9

What is the function of mitochondria?

Answer 9

Carries out aerobic respiration

Question 10

What is the function of the chloroplast?

Answer 10

Carry out photosynthesis

Question 11

What is the function of the permanent vacuole

Answer 11

Stores cell sap, which helps keep the cell turgid.

Question 12

What is the function of centrioles?

Answer 12

Produces cillia during interphase

Produces aster and spindle during cell division

Question 13

What is the function of the vacuole (many)

Answer 13

Play an important role in endocytosis and exocytosis is by storing waste material
Can destroy bacteria when the bacterium is engulfed

Question 14

What is the function of the cell wall?

Answer 14

Provides cell with both structural support and protection

Acts as a filtering mechanism

Question 15

What are the key differences between prokaryotic cells and eukaryotic cells

Answer 15

• Eukaryotes have a nucleus, pro don’t
• Eukaryotes have membrane-bound organelles, pro don’t
• Eukaryotes are typically bigger than pro

Question 16

What is the prokaryote cell ultrastructure?

Answer 16

• Outer membrane
• inner membrane
• DNA
• ribosomes
• flagellum (some)
• cytoplasm
• cell wall
• bacterial chromosome
• pilli

Question 17

Organelles involved in protein production.

Answer 17

Rough Endoplasmic Reticulum 
Ribosomes (on RER)
Vesicles
Golgi apparatus
Cytoskeleton
Cell surface membrane

Question 18

Process of protein production and synthesis.

Answer 18

1) RNA produced by nucleus
2) Ribosomes attached to rough Endoplasmic reticulum carry out protein synthesis and package proteins into vesicles
3) Vesicles travel to Golgi apparatus via cytoskeleton
4) Vesicles fuse with cis. face of Golgi apparatus and proteins enter
5) In Golgi Apparatus, proteins are structurally modified and repackaged into vesicles
6) Vesicles travel via cytoskeleton and fuse with the cell surface membrane and proteins exit via exocytosis.

Question 19

What is the ultrastructure of plants?

Answer 19

80s free ribosome
Chloroplasts
Tonoplast
Golgi apparatus 
Nucleus
Nucleuolus
RER
SER
mitochondria
Plasma membrane
Cell wall

Question 20

What is the difference in DNA in pro and eukaryotic cells?

Answer 20

Prokaryotes have

• Naked DNA
• Circular DNA
• No introns (usually)

Eukaryotes have
-DNA bound to protein
-Linear DNA
Has introns (usually)

Question 21

What is the difference in reproduction between pro and eukaryotic cells?

Answer 21

Prokaryotic cells:

• Binary fission
• Single chromosome

Eukaryotic cells:

• Mitosis and meiosis
• Chromosomes paired

Question 22

What is the difference in average size between pro and eukaryotic cells?

Answer 22

Prokaryotic cells:

• Smaller
• 1 to 5 micrometers

Eukaryotic cells:

• Larger
• 10 to 100 micrometers

Question 23

What is the cytoskeleton composed of?

Answer 23

• Microfilaments
• Microtubules
• Intermediate fibres

Question 24

What are microfilaments?

Answer 24

• Solid and smaller than microtubules
• Composed of actin
• Provide contractile motion
• Involved in cytokinesis
• Act as a skeleton to support the cell
• Responsible for cell movement

Question 25

What are microtubules?

Answer 25

- Composed of globular tubular proteins - Polymerise to form hollow tube that act as a scaffold - This scaffold determines cell shape - Acts as roads for vesicles and organelles - Self assemble from hollow tube units to form cilia and flagella - Forms spindle fibres that separate chromosomes during cell division.

Question 26

What are intermediate filaments?

Answer 26

- Intermediate diameter between microtubules and microfilaments - Entwined dimers of various proteins - Add mechanical strength and help maintain integrity of the cytoskeleton.