Question 1

In eukaryotic cells both the nucleus and mitochondria have double membranes.

Accepted Answer

Both the nucleus and mitochondria have an outer membrane and an inner membrane, making them both double membrane organelles in eukaryotic cells.

Question 2

Microtubules are composed of tubulin monomers.

Accepted Answer

Microtubules are cylindrical structures composed of tubulin monomers, which are protein subunits.

Question 3

The movements of wound-healing fibroblasts in your body depend on pseudopodia that can extend and retract, because the microfilaments in them can rapidly change their length.

Accepted Answer

Fibroblasts use pseudopodia to move and microfilaments within them can quickly change length to allow for extension and retraction.

Question 4

Cilia are usually thicker and longer than flagella.

Accepted Answer

This statement is false. Cilia are actually shorter and thinner than flagella.

Question 5

Mitochondria produce most of the energy used in a bacterial cell.

Accepted Answer

Mitochondria are not present in bacterial cells, but rather in eukaryotic cells. Bacterial cells produce energy through other processes such as glycolysis, the Krebs cycle, and oxidative phosphorylation.

Question 6

Until recently public health officials had mistakenly believed that the mosquitoes responsible for transmitting malaria primarily live indoors, and thus officials had concentrated eradication efforts on dwellings.

Accepted Answer

This statement accurately reflects the previous understanding of public health officials regarding malaria transmission and eradication efforts.

Question 7

DNA analysis supports the hypothesis that prokaryotes evolved from earlier eukaryotes through adaptive simplification-a process where unnecessary cellular structures are gradually lost.

Accepted Answer

The hypothesis that prokaryotes evolved from earlier eukaryotes through adaptive simplification has not been supported by DNA analysis. Instead, the current consensus is that the opposite occurred, with prokaryotes evolving into eukaryotes by acquiring new membrane-bound organelles through endosymbiosis.

Quiz 6: Cell Structure and Internal Compartments