Question

question 5 (2.5 points)
select the feature that best describes cell membranes:
helps cell move through fluid habitats
contains ribosomes
involved in binding to signaling molecules
physically separates an external environment from an internal one
question 6 (2.5 points)
the plasma membrane is composed mostly of _.
phospholipids
cholesterol

Explanation:

• Question 5: The cell membrane's primary function is to physically separate the internal environment of the cell from the external environment. Flagella or cilia help cells move through fluid habitats. Ribosomes are in the cytoplasm (not a main feature of the membrane). While some membrane proteins bind to signaling molecules, the most fundamental and over - arching feature is the physical separation.
• Question 6: The plasma membrane is a phospholipid bilayer. Cholesterol is present in animal cell membranes (in smaller amounts compared to phospholipids) and helps with membrane fluidity, but phospholipids are the main component.

Answer:

Question 5: physically separates an external environment from an internal one
Question 6: phospholipids