Cell Biology

Question 1

Comparison of prokaryotes and eukaryotes

Answer 1

• Cytoskeletal elements (microtubules, etc.) present in eukaryotes, absent in prokaryotes
• Prokaryotes are 1-10 micrometers in size, eukaryotes are 10-100 micrometers

Question 2

Smooth ER

Answer 2

• System of membrane channels that synthesizes lipids and steroid hormones.
• Connects rough ER to Golgi apparatus.
• Detoxifies cell
• Carbohydrate metabolism

Question 3

Vacuole

Answer 3

Plant cells and human fat (adipose) cells have large central vacuoles

Question 4

Plastids

Answer 4

Have a double membrane, found in plants/algae

• Chloroplasts
• Leucoplasts: colourless, store starch, found in roots
• Chromoplasts: store carotenoid pigments

Question 5

Microtubules

Answer 5

Hollow tubes that make cilia, flagella, and spindle fibres

Question 6

Centrioles and centrosomes

Answer 6

Outside nuclear membrane, organize spindle fibres, only in animals. 2 perpendicular centrioles = 1 centrosome. 9 triplets of microtubules in a circle, same structure as spindle fibres

Question 7

Cilia and flagella

Answer 7

9 pairs of microtubules around 2 singlet microtubules (9+2)

Question 8

Microfilaments

Answer 8

Made of actin protein and support cell shape. Enables formation of cleavage furrow, movement of amoeba, and contraction of skeletal muscles