3.1 Cell Membrane & Nucleus 2025-26

Multiple Choice

Which of the following correctly represents the levels of structural organization in the human body from simplest to most complex?

• Chemical, Cellular, Tissue, Organ, Organ System, Organismal

• Cellular, Chemical, Tissue, Organ, Organ System, Organismal

• Organismal, Organ System, Organ, Tissue, Cellular, Chemical

• Tissue, Organ, Organ System, Organismal, Cellular, Chemical

Multiple Select

Which of the following elements are major components of most cells?

• Carbon

• Hydrogen

• Oxygen

• Calcium

Multiple Choice

What percentage of water are cells approximately composed of?

• 30%

• 60%

• 90%

• 80%

Multiple Choice

What is the primary function of the plasma membrane in a cell?

• It produces energy for the cell

• It separates cell contents from the surrounding environment

• It stores genetic information

• It synthesizes proteins

Multiple Choice

Which of the following is NOT a component of the fluid mosaic model of the plasma membrane?

• Phospholipid bilayer

• Cholesterol

• Glycolipids

• Cell wall

Multiple Choice

What property of phospholipids makes them a good foundation for cell membranes?

• Their ability to store energy

• Their polarity

• Their rigidity

• Their large size

Fill in the Blanks

The hydrophilic heads of phospholipids are oriented on the ___ and ___ surfaces of the membrane.

Multiple Select

Which of the following are specialized functions of membrane proteins?

• Acting as enzymes

• Serving as receptors for hormones

• Transporting substances as channels or carriers

• Storing genetic information

Multiple Choice

What is the main function of tight junctions between cells?

• Allowing free passage of substances

• Binding cells loosely together

• Preventing substances from passing between cells

• Facilitating cell movement

Multiple Choice

How do desmosomes contribute to cellular integrity?

• By storing genetic information

• By allowing free movement of cells

• By preventing cells from being pulled apart

• By facilitating nutrient exchange

Multiple Choice

Which type of cell junction allows communication between cells?

• Tight junctions

• Desmosomes

• Adherens junctions

• Gap junctions

Fill in the Blanks

The control center of a cell is called the

.