Gas Exchange

Question 1

Name three features of efficient gas ex

Answer 1

Large SA
short diffusion pathway
Steep conc grad

Question 2

Why can’t insects use body as exchange surface

Answer 2

Waterproof exoskel small SA:V

Question 3

Explain process of gas exchange in insects

Answer 3

Gas move in and out of tracheae via spiracles
A diffusion gradient allows oxygen diffuse into body while waste co2 diffuse out
Contraction muscles allows mass movement air in/out

Question 4

Adaptations leaf allow effienct gas exchange

Answer 4

1. Thin flat surface = short diffusion pathway
2. Pores underside leaf = gas easily enter
3. Air spaces In spongy mesophyll allow gas move around leaf

Question 5

Three methods of moving gas in tracheal system

Answer 5

1. Diffusion = cells respire use oxygen and produce carbon dioxide creates conc gradient
2. Contract and relax = move gases on mass
3. Flight = muscles cell respire anaerobly produces lactate lowers water potential so water moves into cell by osmosis

Question 6

Human gross structure and ventilation

Answer 6

Trachea bronchi bronchioles alveoli

Breathing in diaphragm contracts external intercostal model contract

Vol increases and pressure decreases in thoracic cavity

Breathing out - diaphram relaxes and internal intercostal muscles contract

Volume decrease and pressure increase in thoracic cavity