B8

Question 1

Uses of energy in the body

Answer 1

muscle contraction
protein synthesis
cell division
growth
maintenance of a constant body temperature

Question 2

Aerobic respiration

Answer 2

chemical reactions in cells that use oxygen to break down nutrient molecules to release energy

Question 3

Anaerobic respiration

Answer 3

chemical reactions in cells that break down nutrient molecules to release energy without using oxygen

Question 4

The features of gas exchange surfaces in humans

Answer 4

large surface area
thin surface
good blood supply
good ventilation with air

Question 5

Inspired air composition

Answer 5

21% Oxygen, 0.04% Carbon Dioxide and Variable Water vapour

Question 6

Expired air composition

Answer 6

16% Oxygen, 4% Carbon Dioxide and Saturated Water vapour

Question 7

Tobacco smoking causes? (Cigarette)

Answer 7

chronic obstructive pulmonary disease(COPD), lung cancer and coronary heart disease

Question 8

Nicotine leads to…

Answer 8

narrowing blood vessels, leads to hypertension due to high BP which can develop into Coronary HD

Question 9

Tar lead to…

Answer 9

contains chemicals called carcinogens. Can cause changes in the behaviour of some cells leading to dividing uncontrollably, this increased growth can result in tumours some of which are malignant

Question 10

CO leads to…

Answer 10

is a poisonous gas which binds with Haemoglobin resulting in less O2 carried in the blood

Question 11

Metabolism

Answer 11

all chemical reactions taking place inside a cell or living organism.

Question 12

Inhalation

Answer 12

-External intercostal muscle contracts
-Internal intercostal muscles relaxes
-This lifts the ribs upwards
-Diaphragm contracts and moves down
-Volume of thorax/chest/lungs increases
-Pressure in thorax/chest/lungs decreases
-Air flows in down the pressure gradient

Question 13

Exhalation

Answer 13

-internal intercostal muscle contracts
-External intercostal muscles relaxes
-This ribs pull inwards
-Diaphragm relaxes and moves up
-Volume of thorax/chest/lungs decreases
-Pressure in the thorax/chest/lungs increases
-Air flows out of the body down the pressure gradient

Question 14

Function of Cilia, Goblet cells and Mucus?

Answer 14

-The mucus is produced by goblet cells and traps bacteria, dust,particles
-The cilia beat
-And push the mucus away from the lungs towards the throat

Question 15

Cystic fibrosis

Answer 15

Cystic fibrosis is caused by a recessive allele of the CFTR gene. Cystic fibrosis affects the lungs by goblet cells producing thick, sticky, dehydrated mucus. much harder for cilia to sweep up the trachea and to the mouth, so mucus accumulates in the airways. As the mucus traps bacteria but the mucus can’t be removed, leads to frequent infections and eventually scar tissue in lungs. The fact that mucus obstructs the airways so gas exchange is less efficient as it is harder for oxygen to reach the lungs and for carbon dioxide to exhale, causing breathing problems.