Unit 4 A Transport and respiration paper 2

Question 1

One adaptation of the leaf for the absorption of light visible?

Answer 1

Large surface area

Question 2

One reason gas exchange is more challenging in larger species of organisms?

Answer 2

Because they have smaller surface area to volume ratio

Question 3

Role of secretion of surfactant during gas exchange in mammalian lungs?

Answer 3

Reduces surface tension and prevents alveoli from collapsing during expiration

Question 4

Role of the dense network of capillaries during gas exchange in mammalian lungs?

Answer 4

Ensures large surface area for gas exchange and maintains steep concentration gradient

Question 5

Two ways in which the human body can increase the heart during exercise?

Answer 5

• Bohr shift
• Increased carbon levels

Question 6

Explain how the sinoatrial node pass to other parts of the heart, so that the beating of the heart is coordinated

Answer 6

find answer

Question 7

Function of left ventricle?

Answer 7

Pump oxygenated blood into aorta

Question 8

Describe two cardiovascular risk factors

Answer 8

Raised blood pressure
- Can lead to coronary heart disease which means parts of the heart are not doing their job causing failures in the heart
Tobacco
- Plays a key role w/lungs that have the oxygen needed to flow w/in the blood. If lungs are damaged a heart disease could be a result + heart cant pump w/out oxygen

Question 9

Explain sounds of heart

Answer 9

1. Lub sound
   - When atrioventricular valves close at beginning of ventricular contarction
2. Dub sound
   - When semi lunar valves close at the end of ventricular contraction