L5Microsporidia, Blastocladiomycota, and Neocallimastigomycota,

Question 1

What is the primary ecological role of Microsporidia?

Answer 1

Microsporidia are unicellular obligate endoparasites that primarily infect invertebrates and vertebrates, playing significant roles in host population dynamics.

Question 2

How many genera and species of Microsporidia are described?

Answer 2

Approximately 200 genera and 1,400 species of Microsporidia are described.

Question 3

What distinguishes Microsporidia from other fungi?

Answer 3

Microsporidia lack mitochondria, possess mitosomes, and have a highly reduced ribosomal RNA and small genomes (2.3 to 19.5 Mb).

Question 4

What is the life cycle of Microsporidia?

Answer 4

The life cycle includes an intracellular and extracellular spore stage, with infection initiated by the ejection of the polar filament into the host cell.

Question 5

Which Microsporidia species are significant human pathogens?

Answer 5

Species such as Enterocytozoon bieneusi and Encephalitozoon cuniculi are notable human pathogens.

Question 6

What symptoms are associated with human microsporidiosis?

Answer 6

Symptoms can include chronic diarrhea, abdominal pain, and wasting, particularly in immunocompromised individuals.

Question 7

What is the ecological niche of Blastocladiomycota?

Answer 7

They thrive in aquatic environments and moist soils, serving as saprobes, parasites, or pathogens of plants and invertebrates.

Question 8

How does sexual reproduction occur in Blastocladiomycota?

Answer 8

Sexual reproduction involves the fusion of gametes to form a diploid thallus, which later undergoes meiosis to produce haploid zoospores.

Question 9

What is a model species of Blastocladiomycota?

Answer 9

Allomyces arbusculus is a key model species used for molecular and biochemical studies.

Question 10

Describe the unique life cycle of Allomyces arbusculus.

Answer 10

Allomyces arbusculus undergoes an alternation of generations, with both haploid and diploid stages, and features anisogamous gametes attracted by pheromones.

Question 11

What is the primary habitat of Neocallimastigomycota?

Answer 11

They are obligate anaerobes found in the rumen or hindgut of herbivorous mammals, where they aid in the digestion of plant materials.

Question 12

How do Neocallimastigomycota contribute to their hosts’ digestion?

Answer 12

They decompose cellulose and hemicellulose, providing essential nutrients to the host by breaking down complex carbohydrates.

Question 13

What are hydrogenosomes, and why are they important for Neocallimastigomycota?

Answer 13

Hydrogenosomes are organelles that enable anaerobic energy production, producing H2 and other fermentation end products crucial for metabolic processes.

Question 14

What is the significance of Neocallimastigomycota in biotechnology?

Answer 14

They have potential applications in probiotics for livestock health, production of polysaccharide-degrading enzymes, and biofuel production.

Question 15

Describe the life cycle of Neocallimastigomycota.

Answer 15

They reproduce asexually through the production of flagellated zoospores, which are released in response to food ingestion by the host.

Question 16

What are the main characteristics of Microsporidia?

Answer 16

Microsporidia are unicellular, obligate endoparasites, typically measuring 1 to 40 µm, with a cell wall containing chitin. They lack traditional mitochondria, instead possessing mitosomes, and have highly reduced genomes.

Question 17

Discuss the unique reproduction of Neocallimastigomycota.

Answer 17

They primarily reproduce asexually via flagellated zoospores, which are released in response to substrate availability, with no sexual reproductive stages identified to date.

Question 18

How are Neocallimastigomycota utilized in biotechnology?

Answer 18

They are explored for use as probiotics in livestock, as sources of polysaccharide-degrading enzymes for industrial applications, and for biofuel production by converting lignocellulosic biomass into fermentable sugars.

Question 19

Describe the metabolic adaptations of Neocallimastigomycota.

Answer 19

They utilize hydrogenosomes for anaerobic respiration, producing hydrogen and organic acids as byproducts of fermentation, which are critical for their energy metabolism.

Question 20

Explain the role of Neocallimastigomycota in herbivore digestion.

Answer 20

They aid in the digestion of cellulose and hemicellulose in the rumen, producing cellulases and other enzymes to break down complex plant materials into simpler compounds.

Question 21

What are the characteristics of the sexual reproduction process in Blastocladiomycota?

Answer 21

Sexual reproduction involves anisogamous gametes, with male gametes attracted to female gametes by pheromones, resulting in zygote formation and subsequent diploid thallus development.