6.3 - Gas Exchange in Insects

Question 1

yello

Answer 1

bye
don’t drink caffine.
Nick mccarthyyyyyyy

Question 2

Why do insects need gas exchange?

Answer 2

• To deliver oxygen to cells
• To remove carbon dioxide from cells

Question 3

Why do insects need efficient gas exchange systems?

2 reasons but there really obvious bro

Answer 3

To deliver oxygen to cells - This allows aerobic respiration to occur to release energy for cellular processes.
To remove carbon dioxide from cells - The build up of carbon dioxide produced as a waste product of respiration reduces pH, which can denature enzymes.

Question 4

What conflicting needs do insect gas exchange systems balance? (Check)

Answer 4

Maximizing gas exchange
Minimise water loss

Question 5

What covers the insect exoskeleton to prevent water loss?

Answer 5

Waterproof cuticle

Question 6

What are the main structures of the insect gas exchange system?

There are 3

Answer 6

• Tracheae - These are air-filled tubes branching throughout the body.
• Tracheoles - These are fine branches of tracheae that deliver gases to cells.
• Spiracles - These are external openings of the tracheal system on the exoskeleton along the abdomen and thorax.

Question 7

What are tracheae?

Answer 7

Air-filled tubes branching throughout the body

Question 8

What are tracheoles?

Answer 8

Fine branches of tracheae delivering gases to cells

Question 9

What are spiracles?

Answer 9

External openings of the tracheal system

Question 10

What are adaptations of tracheae?

Name 1

Answer 10

• Reinforced with spirals of chitin - This prevents collapsing.
• Multiple tracheae - This increases surface area.

Question 11

What are adaptations of tracheoles?

Name 3

Answer 11

• Penetrate directly into tissues - This reduces the gas diffusion distance.
• Thin walls - These reduce the gas diffusion distance.
• Highly branched - This maximises the surface area.
• Not reinforced with chitin - This allows gas exchange to occur.
• Fluid at the ends of the tracheoles (tracheal fluid) - This allows oxygen to dissolve to aid diffusion and reduces

Question 12

What are adaptations of spiracles?

Answer 12

Open and close - This allows them to control gas exchange with the atmosphere and minimise water loss.

There is only 1 doesnt need to be checked

Question 13

How does gas exchange occur in insects?

6 steps

Answer 13

• Air enters the tracheal system through open spiracles.
• Air moves into larger tracheae and diffuses into smaller tracheoles.
• Tracheoles branch throughout the body, transporting air directly to cells.
• Oxygen dissolves in water in tracheal fluid and diffuses down its concentration gradient from tracheoles into body cells.
• Carbon dioxide diffuses down its concentration gradient out of body cells into the tracheoles.
• Air is then carried back to the spiracles via the tracheae and released from the body.

Question 14

How are concentration gradients maintained?

Answer 14

• Cells using up oxygen for respiration - This keeps oxygen concentration low in cells.
• Cells producing carbon dioxide in respiration - This keeps carbon dioxide concentration high in cells.
• Continuous ventilation - Fresh air is supplied to the tracheal system via spiracles.

Question 15

What are other ventilation mechanisms in insects?

name 1

Answer 15

Mechanical active ventilation - This is when muscles around the tracheae contract and relax, changing the volume and pressure in the abdomen and squeezing the tracheae to pump air in and out of the spiracles.
Tracheal fluid - This moves out into tissues during exercise to increase the diffusion rate and surface area for gas exchange.
Enlarged collapsible tracheae, or accessory sacs and air reservoirs - These inflate or deflate to ventilate the tracheal system and can increase the volume of air moved through the system.
Wing muscles connected to sacs - These pump air to ventilate the tracheal system.
Vibration of thoracic muscles - This pumps air to ventilate the tracheal system.

Question 16

How does lactate accumulation affect gas exchange?

Answer 16

• Lactate accumulation reduces the water potential in tracheal fluid at the end of tracheoles.
• Water leaves the tracheoles via osmosis.
• A higher surface area is exposed for gas exchange.

increases it