Textbook Notes: Fungi

Question 1

What are fungi?

Answer 1

Fungi are eukaryotic organisms.

Question 2

Describe the structure of Fungi.

Answer 2

Fungi are structured in filaments called hyphae, which are made up strings of cells and seperate from one another. Many of these hyphae grouped together make up mycelium.

Spore - particle (s) that allow fungi to be reproduced.
Sporangium - the case/sac where spores are produced.
reproductive and feeding hyphae.

Question 3

How do fungi obtain nutrients?

Answer 3

Feeding hyphae grow down and secrete enzymes into food. The enzymes create simpler substances that are absorbed by active transport and used either as:

• raw materials for growth
  or
  -in respiration for energy.

Digestion is extracellular.

Question 4

What are the harmful uses of fungi?

Answer 4

They excrete toxins which can:

• spoil food and make it dangerous to eat, e.g: some produce waste that are cancer causing substances.

Question 5

What are the beneficial uses of fungi?

Answer 5

• Many antibiotics are produced by fungi, eg the antibiotic penicillin is produced in nature by the Penicillium fungus.
• Yeast is used in bread making, brewing and wine making. Yeast cells ferment glucose, forming ethanol and carbon dioxide:

glucose → ethanol + carbon dioxide

The carbon dioxide is used in brewing and bread-making, and the ethanol is the alcohol of brewing and wine-making.

Question 6

How does reproduction occur in fungus?

Answer 6

Hyphae grow upwards and produce swellings called sporangia (sporangium) at their tips.

Inside each sporangium large numbers of spores are produced.

When they mature, the spore case bursts open, releasing the spores. If they land on suitable conditions, the spore will grow into an identical fungus as the parent.

Question 7

How is the respiration of yeast used in the wider world?

Answer 7

AEROBIC RESP.

• occurs during bread making, produces water and carbon dioxide (makes dough rise).

when air runs out,

yeast respires anaerobically - FERMENTATION
- produces CO2 and ethanol or lactate (alcohols).

Question 8

How do fungi contribute to the carbon cycle?

Answer 8

The decomposers in the cycle (bacteria and fungi) contribute most CO2 to the atmosphere. They feed on dead organic matter and release carbon and oxygen into the atmosphere as CO2 as they respire.

Question 9

How do fungi contribute to the nitrogen cycle?

Answer 9

Decomposers (bacteria and fungi) break down dead plants and animals to release the nitrogen trapped inside.