Size And Surface Area

Question 1

What do cells need to take in?

Answer 1

Oxygen

Nutrients

Question 2

Why do cells need oxygen?

Answer 2

For aerobic respiration

Question 3

What type of waste products do cells excrete?

Answer 3

Carbon dioxide

Urea

Question 4

Why does heat need to be exchanged?

Answer 4

So organisms need to stay at the same temperature

Question 5

What does an organisms surface area : volume ratio affect?

Answer 5

How quickly substances are exchanged

Question 6

What type of surface are : volume ratio does smaller organisms have?

Answer 6

Higher surface area : volume ratio

Question 7

What type of surface are : volume ratio does larger organisms have?

Answer 7

Smaller surface area : volume ratio

Question 8

What substances do organisms need to supply all its cells with?

Answer 8

Glucose

Oxygen

Question 9

Why do organisms need to remove waste products from every cell?

Answer 9

To avoid damaging itself

Question 10

How do single-celled organisms transport substances?

Answer 10

Substances diffuse directly in and out of cells across the cell-surface membrane

Question 11

What is the diffusion rate in single-celled organisms?

Answer 11

Quick because there is small distances the substances have to travel

Question 12

Why, in multicellular organisms, is diffusion across the outer membrane too slow?

Answer 12

Some cells are deep within the body

Larger animals have a low surface area : volume ratio

Question 13

What do multicellular organisms need to have to absorb and excrete substances?

Answer 13

Specialised exchange organs

Question 14

What is mass transport?

Answer 14

Efficient system to carry substances to and from individual cells

Question 15

What is mass transport in mammals?

Answer 15

The circulatory system

Question 16

What is the circulatory system?

Answer 16

Blood carrying Glucose and Oxygen around the body

Also carries hormones, antibodies and waste CO2

Question 17

What does mass transport involve in plants?

Answer 17

The transport of water and solutes in the xylem and phloem

Question 18

What does the metabolic activity inside cells create?

Answer 18

Heat

Question 19

What does the rate of heat loss from an organism depend on?

Answer 19

Surface area

Question 20

If an organism has a large volume what is its surface area?

Answer 20

Relatively small

Making heat loss harder

Question 21

Is an organism has a smaller volume what is its surface area?

Answer 21

Relatively large

Making heat loss easier

Question 22

What type of metabolic rate does a smaller organism need?

Answer 22

High metabolic rate in order to generate enough heat to stay warm

Question 23

What type of shape do animals with a small surface area : volume ratio?

Answer 23

Compact

Question 24

What type of surface area : volume do animals with a less compact shape have?

Answer 24

Larger surface area : volume ratio increasing heat loss from their surface

Question 25

What does animals with a high surface area : volume ratio tend to lose?

Answer 25

More water as it evaporates from their surface

Question 26

What do small mammals living in cold regions need to do?

Answer 26

Eat large amounts of high energy foods such as seeds and nuts

Question 27

What might small mammals have to kept warm when the weather is cold?

Answer 27

Thick layers of fur

Hibernate

Question 28

What have larger organisms developed to help lose heat to keep cool?

Answer 28

Large ears to increase their surface area