CLEP Biology Cell Organelle Structure/Function 3

Question 1

The inner mitochondrial membrane is highly folded into structures called cristae. What is the primary advantage of this folding?

Accepted Answer

It increases the surface area for ATP synthase and electron transport chain proteins

Answer

The folding of the inner membrane into cristae greatly increases the surface area available for the electron transport chain and ATP synthase complexes, maximizing ATP production.

Question 2

A cell line is treated with a drug that dissolves all microtubules. Which process would be most immediately disrupted?

Accepted Answer

Chromosome segregation during mitosis

Answer

The mitotic spindle, which separates chromosomes during cell division, is composed of microtubules and would be destroyed by such a drug.

Question 3

Which feature distinguishes rough ER from smooth ER under an electron microscope?

Accepted Answer

Rough ER is studded with ribosomes on its cytoplasmic surface

Answer

The 'rough' appearance of rough ER comes from the ribosomes attached to its cytoplasmic surface, where membrane and secretory proteins are synthesized.

Question 4

Lysosomes fuse with autophagosomes to degrade damaged organelles in a process called autophagy. What would happen if lysosomal enzymes leaked into the cytoplasm?

Accepted Answer

The cell's own proteins and organelles would be digested, leading to cell death

Answer

Lysosomal hydrolytic enzymes are active at low pH and would digest cellular components if released into the cytoplasm, causing autolysis and cell death.

Question 5

Which structural feature allows the nuclear envelope to regulate the passage of molecules between the nucleus and cytoplasm?

Accepted Answer

Nuclear pore complexes

Answer

Nuclear pore complexes are large protein channels that span both membranes of the nuclear envelope and selectively control the transport of molecules in and out of the nucleus.

CLEP Practice Test

CLEP Practice Test

CLEP Biology Cell Organelle Structure/Function 3