exchange surfaces 3.1 (pmt)

Question 1

suggest why the Titicaca water frog has evolved unusually large skin folds (2 marks)

Answer 1

-they have a large sa:v ratio
-this increases rate of oxygen absorption

Question 2

what breathing instructions are given to someone whos volume of vital capacity is being measured (2)

Answer 2

to breathe in as deeply as possible
and force air out as much as possible

Question 3

how might have scientists known that termites evolved in the jurassic geological period (1)

Answer 3

using fossils in the known age

Question 4

what source of evidence can help todays scientists to find out how closely related termites are to cockroaches (1)

Answer 4

using DNA

Question 5

explain how co2 produced in respiring body cells of worker termites is removed to air outside the termite mound (4 marks)

Answer 5

-co2 diffuses down conc gradient out of respiring cell
-blood travels from cell to tracheoles
-respiration generates heat
-hot gases which are less dense expand and rise up to vents to mount top

Question 6

describe how structures of insect tracheal system and fish gills provide a large surface area for gas exchange (2)

Answer 6

inside tracheal system of insects: many tracheoles
fish: many filaments

Question 7

suggest why lugworms evolved external gills

Answer 7

rate of diffusion is insufficient to meet needs

Question 8

which have goblet cells? bronchi, bronchioles or alveoli

Answer 8

only bronchi

Question 9

does bronchi have cartilage

Answer 9

yes

Question 10

state five differences between normal expiration and forced expiration

Answer 10

normal : passive, diaphragm muscles relax and moves up, ribs move down and in, thorax volume reduces
forced: active, need energy, internal intercostal muscles contract, ribs pull down hard