Surface Area

Question 1

What do single celled organisms have to do to survive

Answer 1

Absorb resources:
Oxygen
Glucose
Amino acids

Get rid of waste:
Carbon dioxide

This is done by how big its surface is-compared to its volume (inside the organism)

Question 2

What happened when an organism gets larger

Answer 2

There surface area decreases

Question 3

How to calculate surface area

Answer 3

Area of a single face X 6 (a cube has 6 faces)

Question 4

How to the calculate the volume of a cube

Answer 4

Leng X Width X Height

Question 5

To workout surface area to volume

Answer 5

You find the surface area then find the volume then put it in a rate

Surface area: Volume
Then say how much times bigger the surface area is

Question 6

What happened when the cube gets larger

Answer 6

The surface area+ volume both increase
(The volume increases much more quickly)

Question 7

Because bacteria are small

Answer 7

They have a high surface area to volume ratio
-can rely on diffusion across their surface to exchange anything they need

Question 8

Because humans are big

Answer 8

They have a low surface area to volume ratio
-can’t rely on diffusion (so we have lung and intestine which increase our surface area through the inside of our body this is done with the alveoli in the lungs which gives a huge surface area and the instestines have villi)

Question 9

Diffusions distances

Answer 9

As organisms get larger the distance that molecules would have to diffuse to get from the outside of their body to the inside increases massively

So humans rely on transport systems such as:
Circulatory system which transfers molecules from an exchange surface around the body to whichever cells need them

Same with plants but they have phloem and xylem to transport the substances around the plant

Question 10

Large organism

Answer 10

Anything to see with your naked eye