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The net movement of water through a partially permeable membrane from a dilute solution to a more concentrated solution.

The diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane.

Osmosis is the diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane. Water moves both ways, but its net movement is towards the more concentrated solution.

In comparisons, state that osmosis concerns only water and requires a partially permeable membrane. Diffusion and active transport can move other substances.

Keep the transport processes distinct: water enters root hair cells by osmosis, whereas mineral ions can enter by active transport.

When explaining osmosis, state the direction of water movement, refer to a partially permeable membrane and link excessive gain or loss of water to inefficient cell function.

The net movement of water through a partially permeable membrane from a more dilute solution to a more concentrated solution.

The net movement of water molecules through a partially permeable membrane from a dilute solution to a more concentrated solution.

A difference in concentration between two regions is called a concentration gradient. This gradient determines the direction of diffusion and osmosis, while active transport allows cells to move substances in the opposite direction.

The net movement of water molecules through a selectively permeable membrane from a dilute solution to a more concentrated solution.

The net movement of water molecules through a partially permeable membrane from a more dilute solution to a more concentrated solution.

The net movement of water through a partially permeable membrane from a more dilute solution to a more concentrated solution.

The overall movement of water molecules from higher water potential to lower water potential through a partially permeable membrane.

Three important processes move substances across it—diffusion, osmosis and active transport. Their crucial differences are the substance being moved, the direction of movement and whether cellular energy is required.

The net movement of water through a partially permeable membrane from a region of higher water potential to a region of lower water potential.

The net movement of water molecules through a partially permeable membrane from a region of higher water potential to a region of lower water potential.

The net movement of water through a partially permeable membrane from a more dilute solution to a more concentrated solution.

Osmosis is the net movement of water through such a membrane from a more dilute solution to a more concentrated solution. A dilute solution has more water molecules relative to dissolved substances, so more water crosses towards the concentrated side than crosses back. No energy from the cell is needed.

The net movement of water molecules through a partially permeable membrane from a region with a higher concentration of water molecules to one with a lower concentration.

The net movement of water through a partially permeable membrane from a higher water concentration to a lower water concentration.

The movement of water through a partially permeable membrane from a more dilute solution towards a more concentrated solution.

Osmosis

Definition

How each exam board covers it

AQA GCSE Biology · 8461

Exam tips

Revise Biology with GradeGen

Edexcel GCSE Biology · 1BI0

OCR GCSE Biology A · J247

OCR GCSE Biology B · J257

Definition

How each exam board covers it

AQA GCSE Biology · 8461

Exam tips

Related key terms

Revise Biology with GradeGen

Edexcel GCSE Biology · 1BI0

OCR GCSE Biology A · J247

OCR GCSE Biology B · J257