IB Biology SL

The benefit of a cell membrane includes

• formation of an internal environment in which optimal conditions can be maintained.

• the rigid structure forms a protective layer.

• allowing any materials to free flow in and out of the internal environment.

Tags

NGSS.MS-LS1-2

The formation of membrane-bound organelles such as a the nucleus and rER is likely due to

• infoldings in the external membrane that then pinched off.

• a mutualistic relationship with a proteobacterium.

• transcription by DNA into mRNA.

• supercoiling of the nucleoid region.

The prokaryotic cell which evolved into the first mitochondria is hypothesized to have been an

• aerobic bacterium.

• anaerobic bacterium.

It is hypothesized that monomers were able to form into polymers

• in laboratory conditions only.

• at deep sea thermal vents.

• through endosymbiosis.

• due to the formation of the cell membrane.

The diagram shows a section through a membrane. What are the modes of transport in the diagram?

• A

• B

• C

• D

Which graph best represents the relationship between the concentration of chloride ions in the external environment of a cell and the rate at which the chloride ions move by facilitated diffusion into the cytoplasm of the cell?

• A

• B

• C

• D

The diagrams represent cells with the same concentration of dissolved substances in their cytoplasm. If all the cells were placed in the same hypertonic sucrose solution, which cell would show the greatest rate of change in the concentration of its cytoplasm?

• A

• B

• C

• D

Tags

NGSS.MS-LS1-2

Dialysis membrane was set up to model digestion and absorption in the small intestine.

What is a limitation of this model?

• A. There can be no active transport.

• B. Maltose will pass through the membrane.

• C. Lipase should be present with protein.

• D. The membrane is not permeable to starch.

What is the difference between simple diffusion and facilitated diffusion?

• A.

• B.

• C.

• D.

Cells in the adrenal gland produce the hormone epinephrine and store it in vesicles. To release epinephrine these vesicles are carried to the plasma membrane and fuse with it. What process is occurring?

• A. Expulsion

• B. Exchange

• C. Excretion

• D. Exocytosis