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Draw a large labelled diagram to show the structure of Rhizopus during asexual reproduction - Leaving Cert Biology - Question 15(a) - 2019
Question 15(a)
Draw a large labelled diagram to show the structure of Rhizopus during asexual reproduction. What mode of nutrition does Rhizopus use? Describe an environmental co... show full transcript
Worked Solution & Example Answer:Draw a large labelled diagram to show the structure of Rhizopus during asexual reproduction - Leaving Cert Biology - Question 15(a) - 2019
Step 1
Draw a large labelled diagram to show the structure of Rhizopus during asexual reproduction.
Answer
To illustrate the structure of Rhizopus during asexual reproduction, draw a large labelled diagram that includes the following components:
- Mycelium: The network of hyphae.
- Stolon: Structures that connect different parts of the fungus.
- Sporangiophore: Specialised hyphae that bear sporangia.
- Sporangium: The sac-like structure where spores are produced.
- Rhizoid: Root-like structures that anchor the fungus and absorb nutrients.
- Columella: The sterile part of the sporangium that supports the spores.
Make sure the diagram is large enough for clear labels, and ensure the associated parts are pointed out with arrows.
Step 2
Step 3
Describe an environmental condition that would cause Rhizopus to reproduce sexually.
Answer
An environmental condition that could trigger sexual reproduction in Rhizopus is a lack of water or extreme temperatures. These stressors may prompt the organism to switch from asexual to sexual reproduction to increase genetic diversity and enhance survival under adverse conditions.
Step 4
Describe in detail the process of sexual reproduction in Rhizopus.
Answer
The process of sexual reproduction in Rhizopus involves several steps:
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Mating Types Formation: Rhizopus fungi have different mating types, often referred to as '+' and '-' strains. These strains must come into contact to initiate sexual reproduction.
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Swelling Formation: When the compatible strains meet, they form swellings on the hyphae where the nuclei of both mating types can migrate.
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Production of Gametangia: The swollen areas develop into gametangia, which are structures that produce gametes (the reproductive cells).
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Fusion of Gametes: The gametes from the gametangia fuse, resulting in the formation of a zygote, a fertilized cell that holds genetic material from both parent strains.
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Zygospore Formation: The zygote then develops into a thick-walled zygospore, which is a resting (dormant) spore that can withstand harsh environmental conditions.
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Meiosis and Germination: When conditions become favorable, the zygospore undergoes meiosis to produce new spores that can germinate and develop into new hyphae, thus continuing the life cycle.