B1.5 The respiratory system, breathing and respiration - respiratory surfaces

Question 1

Need for transport and exchange systems

Answer 1

Larger organisms have smaller surface area to volume ratios and are unable to directly obtain useful substances from their environment like single-celled organisms can

Question 2

Surface area

Answer 2

The total area of the surface of an object

Question 3

Surface area to volume ratio

Answer 3

The amount of surface area in relation to how large something is

Question 4

Large surface area to volume ratio

Answer 4

Large surface area to volume ratio

Question 5

Diffusion

Answer 5

The movement of substances such as gas particles or substances in solution, from a higher concentration to a lower concentration

Question 6

Gas exhange

Answer 6

When oxygen and carbon dioxide move in and out of cells by diffusion

Question 7

Purpose of gas exchange

Answer 7

Organisms need oxygen for aerobic respiration, they also need to remove carbon dioxide which is a waste product in some organisms

Question 8

Sites of gas exchange

Answer 8

The alveoli of the lungs and respiring cells around the body

Question 9

Alveoli adaptations

Answer 9

Has a large surface area, a good blood supply, is moist, is well ventilated for gas exchange and has a thin membrane for diffusion

Question 10

Moist lining of alveolus

Answer 10

The lining of the alveolus is moist, which increases the rate of diffusion

Question 11

Wall of capillary

Answer 11

The capillary walls are thin and one cell thick to optimise diffusion between the alveoli and the blood

Question 12

Many blood vessels surrounding the alveoli

Answer 12

Provide a constant blood supply to maintain a constant diffusion gradient for gas exchange

Question 13

Specific cells, tissue and sacs adapted for exchange

Answer 13

Alveoli in mammal lungs, guard cells in plants, spongy mesophyll cells in plants

Question 14

Oxygen

Answer 14

A gas that is needed for aerobic respiration to release energy, oxygen is transported into the body by the respiratory system and around the body by the circulatory system

Question 15

Respiratory system

Answer 15

A system of organs, functioning in the process of gas exchange between the body and the environment, consisting of the trachea, bronchi and lungs

Question 16

Carbon dioxide

Answer 16

A waste product of respiration that needs to be removed from the body via the circulatory system, also an essential reactant in plants that is transported in to plant leaves via the stomata

Question 17

Gas exchange in plants

Answer 17

Carbon dioxide diffuses into the plant in exchange for oxygen that diffuses out of the plant, this process is regulated by guard cells in the leaves that can open and close the stomata efficiently

Question 18

Leaf adaptations as a respiratory surface

Answer 18

Leaves have pores called stomata that can open and close to regulate gas exchange, they also have a layer of cells called the spongy mesophyll that is very spacious allowing room for diffusion and gas exchange

Question 19

Spongy mesophyll

Answer 19

Loose tissue beneath the palisade layer of a leaf, has many air spaces between its cells and an increased surface area for diffusion

Question 20

Lungs

Answer 20

Are specialised in gas exchange due to the presence of many tiny sacs called alveoli that are adapted for diffusion due to being moist, one cell thick and surrounded by capillaries