Insect Transport

Question 1

What is an open circulatory system?

Answer 1

-Few vessels to contain the transport medium, pumped straight from heart to haemocoel-> direct contact with tissue.
-Returns to heart through open ended vessel

Question 2

Where does gas exchange take place in insects? Why?

Answer 2

In the tracheal system.
Because haemolymph(insect blood) doesn’t have haemoglobin.

Question 3

What does the haemolymph transport?

Answer 3

Food, nitrogenous waste and cells involved in disease defence

Question 4

Whats are the negatives of haemolymphs circulation?

Answer 4

-Steep diffusion gradients cant be maintained for efficient diffusion. -Amount of haemolymph flowing to particular tissue cannot be varied to meet changing demands.

Question 5

How is an insect heart different to an animal heart?

Answer 5

The body cavity is split by a membrane, the heart extends along the length of the thorax and insect abdomen

Question 6

How do insects do gas exchange?

Answer 6

They have small openings called spiracles that allow movement of gas in and out of insect, controlled my muscles called sphincter.

Need this because they have a hard exoskeleton made of chitin

Question 7

In what order does the air move round insects?

Answer 7

Spiracles-trachea-tracheoles-cells

Question 8

Explain the role of tracheoles in gas exchange

Answer 8

Trachea have chitin, so gas exchange cant happen here.
They split into smaller tubes called tracheoles, which have no chitin and make direct contact with respiring cells

Question 9

Explain what happens in an insect after anaerobic respiration

Answer 9

Ends of tracheoles are filled with tracheal fluid, this diffuses into cells because cells water potential has decreased due to lactic acid presence. This allows a bigger surface area for gas exchange