Note: To use this page as intended your browser must be JavaScript enabled.

Click on the question buttons (left) to navigate to the questions, type your answer in the text area provided below each question and then click the submit button (your answer will then appear below the text area). After answering a question, click on the answer button to view a sample answer. Compare your answer to the sample answer. If your answer is significantly different, I suggest you examine how you arrived at your answer. Instructions for saving this page with your responses.

Haustoria Questions

Question 1

Submit Answer 1

Answer 1

Haustoria are commonly found in biotrophic associations, but are not ubiquitous. The haustorium appears to be one mechanism enabling increased access to host organic carbon. However, hyphae growing between cortical cells also appear to be able to obtain sufficient nutrition.

Top

Question 2

Submit Answer 2

Answer 2

If we use the term in its broadest sense, the haustorium is an increased surface area of contact between host and fungus. The increase in surface area of contact, with associated reduced wall, enables flow of solutes in both directions. In only a few cases, though the arbuscule is common, is the fungus likely to benefit the host. In most types, the fungus is entirely parasitic and obtains its complete nutritional requirements from the host.

Top

Question 3

Submit Answer 3

Answer 3

The host/fungus interface is increased in both arbuscules and haustoria. The organisms exchange nutrients across the interface. They differ in that haustoria may have a zone at the neck of the inclusion where the interfacial region is sealed, enabling the interfacial region to be physiologically separated from the rest of the plant intercellular complex. The consequence of the neckband is that the fungus can localise its metabolic activities in energy acquisition to the haustorium. The remainder of the thallus can become specialised in transport or reproduction.

Top

Question 4

Submit Answer 4

Answer 4

 

Top

Question 5

Submit Answer 5

Answer 5

 

Top

Question 6

Submit Answer 6

Answer 6

 

Top

Question 7

Submit Answer 7

Answer 7

 

Top