Movement of Molecules In and Out of Cells

Question 0

What is osmosis?

Answer 0

Movement of water from a dilute solution to a more concentrated solution through a partially permeable membrane

Question 1

How do dissolved substances move in and out of cells?

Answer 1

Diffusion and active transport

Question 2

What is the effect of osmosis?

Answer 2

Gradually dilute a solution

Question 3

Give an example of osmosis in plants

Answer 3

In root hair cells, water moves from soil into cell by osmosis along the concentration gradient

Question 4

What is lost through sweating?

Answer 4

Water and ions (salts)

Question 5

What would happen if ions and water is not replaced after exercise?

Answer 5

Body cells would not function efficiently

Question 6

Why do sports drinks usually contain high amounts of sugar?

Answer 6

To replace the sugar used in energy release

Question 7

What is active transport?

Answer 7

The movement of substances from and area of low concentration to an area of high concentration (against the concentration gradient) using energy

Question 8

How are villi in the small intestine adapted to exchange materials effectively?

Answer 8

Large surface area to increase diffusion sites
Rich blood supply to maintain concentration gradient
Thin walls to provide short diffusion pathway

Question 9

How does the small intestine exchange substances?

Answer 9

Diffusion

Active transport

Question 10

How are alveoli in the lungs adapted to exchange substances efficiently?

Answer 10

Large surface area to increase diffusion sites
Rich blood supply to maintain concentration gradient
Thin walls to provide short diffusion pathway

Question 11

How are substances exchanged in the alveoli?

Answer 11

Diffusion

Question 12

What substances diffuse in the alveoli?

Answer 12

Carbon dioxide from blood into alveoli

Oxygen from alveoli into blood

Question 13

What is the proper name for the windpipe?

Answer 13

Trachea

Question 14

Describe how air moves into the lungs

Answer 14

Intercostal muscles contract causing the Ribcage to move outwards are upwards
Diaphragm moves down
Increases volume of lungs which decreases pressure causing air to be drawn in

Question 15

Describe how air moves out of the lungs

Answer 15

Intercostal muscles relax causing the Ribcage to move inwards are downwards
Diaphragm moves up
Decreases volume of lungs which increases air pressure, forcing air out

Question 16

What is the name of the process where water vapour is lost in plants?

Answer 16

Transpiration

Question 17

What is transpiration?

Answer 17

Evaporation of water from plants (through stomata)

Question 18

How can the guard cells affect how much water is lost?

Answer 18

The size of the stomata is controlled by the guard cells
If plant looses water faster than it is taken up by the roots, the stomata can close
Prevents wilting and dehydration

Question 19

What weather conditions does transpiration happen fastest?

Answer 19

Hot, windy and dry because the stomata are closed to prevent diffusion so photosynthesis has to stop

Question 20

How does a negative pressure breathing aid force someone to breath?

Answer 20

Causes chest to rise due to reduced pressure outside chest

Question 21

How does a positive pressure breathing aid force someone to breath?

Answer 21

Forces air into the lungs

Question 22

How does wind speed affect transpiration?

Answer 22

As wind speed increases, transpiration increases because water evaporates faster from the surface of the leaf. The concentration gradient is increased

Question 23

How does humidity affect transpiration?

Answer 23

As humidity increases, the rate of transpiration decreases because less water evaporates as the air is already full of water. The concentration gradient decreases.

Question 24

How does an increase in temperature affect transpiration?

Answer 24

The rate of transpiration increases because it increases the rate of evaporation.