5.2 Flashcards
What features do terrestrial insects have that helps in reducing water loss? Explain each. (4)
(1) Waterproof coverings —> (2) it has a waxy, rigid outer skeleton
(3) Small SA:V ratio —> (4) minimises the area over which water is lost.
What are spiracles in insects? (2)
(1) Tiny openings that allow gases to enter and leave the tracheae
(2) Spiracles can be opened and closed by a valve.
What is the primary function of the tracheal system in insects? (1)
To facilitate gas exchange between the environment and the cells
How do spiracle movements benefit terrestrial insects? (2)
(1) They allow for the opening and closing of spiracles to exchange gases (2) while minimizing water loss
What is the significance of diffusion in the tracheal system? (1)
Diffusion allows oxygen to enter and carbon dioxide to exit efficiently due to concentration gradients
What conflict do terrestrial insects face regarding their tracheal system? (1)
The need to exchange respiratory gases versus the need to conserve water
What is the result of the diffusion gradient created by cellular respiration in insects? (2)
(1) spiracles open, due to a rise in CO2 concentration
(2) Oxygen diffuses from the atmosphere into the cells, while carbon dioxide diffuses out
What adaptation do insects have to maintain gas exchange efficiency? (1)
A short diffusion pathway provided by the tracheoles extending throughout the body
Fill in the blank: The tracheae are supported by strengthened rings to prevent them from _______.
collapsing
True or False: Insects can use their body surface to exchange gases like single-celled organisms.
False
Describe how single-celled organisms exchange gases. (2)
(1) Through direct diffusion across their cell-surface membrane…
(2) …due to a large surface area to volume ratio
What role do muscle movements play in the insect tracheal system? (2)
(1) They create ventilation,
(2) speeding up yhe process of gas exchange
What occurs when the spiracles are closed? (2)
(1) Gas exchange is limited,
(2) water loss is minimized
How does atmospheric air contribute to gas exchange in insects? (1)
(1) It provides oxygen that diffuses into the tracheae and tracheoles
What happens to the concentration of oxygen in the tracheae when cells are respiring? (1)
(1) The concentration of oxygen decreases
