OCR A-Level Biology Chapter 7

Question 1

Features of Specialised exchange surfaces

Answer 1

• Increased surface area
• Thin Layers
• Good Blood Supply
• Good Ventilation

Question 2

What is the structure of the Trachea?

Answer 2

• There are strong, flexible incomplete cartilage rings to stop it from collapsing
• Goblet cells produce mucus to clean the trachea
• Is lined with ciliated epithelial cells to move mucus up and out of the trachea

Question 3

What are the Bronchi?

Answer 3

They are what the trachea splits into, the left bronchus leading to the left lung and vice versa. They are similar in structure to the trachea but smaller.

Question 4

What are Bronchioles?

Answer 4

The bronchi divide into many small bronchioles. They contain no cartilage, only smooth muscle with a flattened layer of epithelial cells which makes a small amount of gaseous exchange possible.

Question 5

What are the Alveoli and what is their function?

Answer 5

The alveoli are the air sacs found in the lungs where gaseous exchange takes place. They are lined with epithelial cells which allow gaseous exchange to take place.

Question 6

What are the adaptations of the alveoli?

Answer 6

• The alveoli have thin walls (one cell thick)
• a good blood supply
• Increased surface area
• Good ventilation