The Cell Membrane and Passive Transport Quiz Review

What is the outer boundary of the animal cell called?

• cytoplasm

• phospholipid bilayer

• nuclear membrane

• endoplasmic reticulum

Answer explanation

The outer boundary of an animal cell is called the phospholipid bilayer, which forms the cell membrane. It regulates what enters and exits the cell, providing structure and protection.

Tags

NGSS.MS-LS1-2

Which of the following molecule is NOT a part of the cell membrane?

• DNA

• phospholipids

• cholesterol

• proteins

Answer explanation

DNA is not a part of the cell membrane. The cell membrane primarily consists of phospholipids, cholesterol, and proteins, which contribute to its structure and function.

What is the job of the cell membrane?

• The cell membrane makes proteins.

• The cell membrane breaks down waste and food with digestive enzymes.

• The cell membrane controls what enters and exits the cell.

• The cell membrane packages proteins for transport.

Answer explanation

The cell membrane controls what enters and exits the cell, acting as a selective barrier. This function is crucial for maintaining homeostasis and allowing necessary substances to pass while keeping harmful ones out.

Tags

NGSS.MS-LS1-2

Which of the following statements is NOT correct regarding the plasma membrane structure?

• Protein molecules are collected toward one side of the cell.

• Phospholipids form a bilayer.

• Phospholipids have a fluid consistency.

• The head of the phospholipid molecule is attracted toward water.

Answer explanation

The statement "Protein molecules are collected toward one side of the cell" is NOT correct. In the plasma membrane, proteins are distributed throughout the bilayer, not localized to one side.

Which of the following statements is NOT correct about the phospholipid molecules in the plasma membrane?

• Each phospholipid molecule has two tails.

• Each phospholipid molecule has one phosphate head.

• The phospholipid heads are hydrophobic.

• The phospholipid heads face outward.

Answer explanation

The statement "The phospholipid heads are hydrophobic" is NOT correct. In fact, phospholipid heads are hydrophilic, meaning they are attracted to water, while the tails are hydrophobic and face inward, away from water.

Passive transport is called "passive" because it occurs WITHOUT

• cause.

• energy.

• a concentration gradient.

• a cell wall.

Answer explanation

Passive transport is called "passive" because it occurs WITHOUT energy. This process relies on the natural movement of molecules along a concentration gradient, requiring no input of energy from the cell.

Correctly identify the definition of passive transport.

• A type of membrane transport that does NOT require energy.

• A type of membrane transport that DOES require energy.

• The movement of large particles against their concentration gradient.

• The concentration of ions in the interior of the cell.

Answer explanation

Passive transport is defined as a type of membrane transport that does NOT require energy. This process allows substances to move across cell membranes along their concentration gradient without the use of ATP.

Which of the following is an example of passive transport? Select 3.

• Facilitated Diffusion

• Diffusion

• Osmosis

• Bulk Transport

• Pinocytosis

Answer explanation

Facilitated diffusion, diffusion, and osmosis are all forms of passive transport, which do not require energy. They rely on concentration gradients to move substances across cell membranes.

Which part of the cell membrane is B?

• glycoprotein

• carbohydrate

• phospholipid

• channel protein

Answer explanation

The correct answer is phospholipid, as it forms the fundamental structure of the cell membrane, creating a bilayer that separates the cell from its environment. Glycoproteins and channel proteins are embedded, while carbohydrates are attached.

Which part of the cell membrane is C?

• glycoprotein

• carbohydrate

• phospholipid

• channel protein

Answer explanation

C represents a channel protein, which facilitates the transport of substances across the cell membrane. Unlike glycoproteins and carbohydrates, channel proteins form pores that allow specific molecules to pass through the membrane.