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Biology B3 > Active Transport And Osmosis > Flashcards

Flashcards in Active Transport And Osmosis Deck (13):

Where are villi located?

In the small intestine


How many villi are there in the small intestine?



How are villi specialised to make the absorption of digested food quicker into the blood?

The increase the surface area of the intestines, only have one layer of surface cells and have a very good blood supply


What is active transport?

The movement of molecules against a concentration gradient


Why does having root hair cells mean plants can absorb more water and mineral ions?

They have a bigger surface area


Why do plants use active transport to get mineral ions and water from the soil?

The concentration of mineral ions and water is usually higher in the root hair cell than the soil so only active transport would work


What does active transport require to work?

Energy from respiration


When is active transport used in humans?

It's used in the gut when there is a low concentration of nutrients in the gut but a high concentration of nutrients in the blood


What is osmosis?

The movement of water molecules across a partially permeable membrane from a region of high water concentration to a region of low water concentration


What is a partially permeable membrane?

A membrane with very small holes


What direction does osmosis happen?

Both ways because molecules move randomly


What is the underneath of the leaf?

An exchange surface covered in stomata to let carbon dioxide diffuse through


What diffuses out of the stomata?

Oxygen and water vapour