Biology Topic 2 Osmosis and Plant Transportation

What does selectively permeable mean?

A cell membrane that allows small molecules through but not larger molecules

What is diffusion?

the movement of molecules from an area of high concentration to an area of lower concentration

What is osmosis?

The diffusion of water from a dilute solution to a more concentrated solution through a selectively permeable membrane

What happens when water moves into a plant cell

The plant cell becomes turgid

What are the components of a plant cell?

cell wall, cell membrane, vacuole, nucleus

What happens to a plant cell in a dilute solution?

Vacuole expands

Cell membrane pushes against cell wall

Causes turgor necessary for support

Cell wall stops membrane expanding too much and limits water intake

Why is presence of a cell wall in plant cells important during osmosis?

Prevents the expansion of the membrane to the point of bursting

Why is this cell type important for a plant?

It limits water intake and provides turgor necessary for support

What happens when water moves out of a plant?

It becomes plkasmolysed

What happens to a plant cell when in a concentrated sugar solution?

Plant cell loses water

Vacuole becomes smaller

Cell membrane pulls away from wall

Cell is now plasmolysed

What happens to red blood cells in water?

The cells will, take water in by osmosis and burst in a process called cell lysis

Why is movement of water through a plant important?

Support, transpiration, transportation and photosynthesis

What is transpiration

The evaporation of water from the spongy mesophyll cells followed by diffusion through the leaf air spaces and the stomata

What are 4 environmental factors that effect the rate of transpiration?

Temperature, wind speed, humidity, light intensity

What is a factor of the leaf that can affect transpiration?

Surface area of leaf. The greater the surface area, the greater the number of stomata and so the faster the rate of transpiration