respiration

Question 1

Gas exchange in animals

Answer 1

supplies oxygen for cellular respiration and disposes of carbon dioxide

Question 2

Gas exchange in protozoa (single celled organisms)

Answer 2

Gas transfer occurs across the plasma membrane by simple diffusion.

Question 3

invagination

Answer 3

Inverted folded inward eg lungs

Question 4

evagination

Answer 4

folded outside the body eg gills

Question 5

how do starfish breathe?

Answer 5

with their tube feet as well as their gills (branchial papulae)

Question 6

Fish and gas exchange

Answer 6

water has low oxygen levels but gills can remove >80% by countercurrent flow of blood and water

Question 7

Tracheal systems in insects

Answer 7

the tracheal system consists of tiny branching tubes that penetrate the body. Air enters the tracheoles through openings called spiracles on the insects body surface and passes into smaller tubes called tracheoles. Tracheoles filled with fluid when insect is active fluid is withdrawn from body. this increases the surface area of air in contact with cells.

Question 8

gas exchange in amphibians

Answer 8

Larval amphibians: gills and skin
adult amphibians: lungs and skin
Gills remain in some adult species.

Question 9

gas exchange in birds

Answer 9

lungs are rigid structures and undergo little change in volume.
air sacs expand and contract
air flows unidirectionally
gas exchange system is a cross current

Question 10

What increases surface area in lungs in mammals?

Answer 10

alveoli

Question 11

lungs in mammals

Answer 11

the thickness of the barrier between the blood and the air is only 2 layers of cells, blood vessel and alveoli(air sac)

Question 12

Movement of air

Answer 12

Buccal pressure in air: breathing fish and amphibians
Suction or aspiration: nonavain reptiles, mammals and birds using thoracic and abdominal muscles.

Question 13

Exchange of respiratory gases

Answer 13

gas diffuses from high to low partial pressure.

Question 14

respiratory pigments

Answer 14

needed to bind and transport gases because o2 has a low solubility in water.
In most vertebrates haemoglobin(Fe) contained in the erythrocytes.
In arthropods and molluscs haemocyanin

Question 15

what are the principles of counter current exchange ?

Question 16

what is the tidal volume, residual volume and tidal capacity in humans?

Answer 16

Tidal volume is the volume of air inhaled in a single, normal breath.(500ml) Tidal capacity is the amount of air taken in during a deep breath,(3L) and residual volume is the amount of air left in the lungs after forceful respiration.(1800-2200ml)

Question 17

what does the O2 molecule bind to in haemoglobin

Answer 17

Oxygen binds to the iron in the heme, forming an octahedral iron complex.