BIO 201 Lecture Notes - Lecture 23: Ascomycota, Dikarya, Hypha

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yellowgrasshopper324

29 Apr 2016

School

Stony Brook University

Department

Biology

Course

BIO 201

Professor

John Trueand Ross Nehm

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Document Summary

Production of haploid spores (conidia) at hyphae tips. Cell divisions by unicellular fungi- fission or budding. Sexual reproduction: rare or unknown is some groups, common in others. Sex may have evolved multiple times in fungi. Sex is fungal phylogeny would likely increase tree-length and decrease ci. Reproduction in fungi is two steps (vs. one step in humans) In humans: ab- sperm + egg (cells fuse, nuclei fuse) (plasmogamy) In fungi: a- hyphal cell 1 + hyphal cell 2 (cells fuse) results in b- nucleus 1 + nucleus 2 ( nuclei don"t immediately fuse) (karyogomy) Mating types are genetically different but not physically different. There may be 2 or more mating types (+ and -) Individuals of the same type typically cannot mate, avoiding self-fertilization. Zygospore fungi are saprobes, parasites of insects and spiders, and mutualists of other fungi. The hyphae are coenocytic and spread in a radial pattern from the spore, with stalked sporangiophores reaching up into the air.

Related Questions

1. Which of the following is NOT true of mycorrhizae?

A) This groupâs name means âfungus rootsâ

B) Plant roots provide mutualistic mycorrhizae with organic nutrients

C) Mycorrhizal fungi may form a mutualistic symbiosis with plants

D) Mycorrhizal fungi provide plants with organic nutrients absorbed from the soil

2. Which of the following terms is INCORRECTLY defined or identified?

A) saprobic fungi-eukaryotic heterotrophs which absorb their nutrients from living organisms

B) plasmogamy-the union of the cytoplasms of two parent mycelia

C) dikaryon-the stage in fungal sexual reproduction in which hyphae contain pairs of haploid nuclei of opposing mating types

D) zygosporangia-the environmentally resistant dikaryotic stage of the Zygomycota

3. In the Kingdom Fungi,

A) a mycelium is a body formed of a network of hyphae

B) a haploid multicellular form alternates with a diploid multicellular form

C) coenocytic hyphae have multiple cross-walls with large pores

D) cell walls are reinforced with proteins similar to collagen

4. Which of the following groups is INCORRECTLY matched with a structure for asexual reproduction?

A) Zygomycota-sporangium(sporangia)

B) Yeast-budding off of new yeast cells

C) Basidiomycota-basidium(basidia)

5. Select the TRUE statement about animal development:

A) Deuterostome development is indeterminate

B) Mesoderm in protostomes arises as outpocketings of the primitive gut

C) In deuterostomes, the blastopore ultimately becomes the mouth of the adult

D) Radial cleavage is characteristic of protostome development

E) All of the above are true

azurecricket62

1.A mycologist visits your biology class and discusses herresearch on a particular fungus that lives on the bark of damagedspruce trees. She explains that the fungal hyphae of her researchorganism is heterokaryotic. You raise your hand and request thatshe define that word. Her correct response is

heterokaryotic means that thenuclei of the fungal hyphae are genetically the same.

heterokaryotic means that eachcompartment of the hyphae contain two distinct nuclei.

heterokaryotic means that thenuclei of each compartment of the hyphae are geneticallydistinct.

heterokaryotic means that each compartment of the hyphaecontains only one nucleus.

2. Select the true statements concerning reproduction ofbasidiomycetes. (Check all that apply.)

The adult forms of a typicalbasidiomycete consists of a mass of dikaryotic primarymycelia.

The secondary mycelia fuse to formprimary mycelia. The primary mycelia form the fruiting body.

The gills of an Amanitamushroom contains basidiospores.

Karyogamy produces a diploid zygotethat undergoes meiosis.

Meiosis produces basidiospores, and the fusion of spores fromdifferent mating strains produces the primary mycelium.

3. In the life cycle of a zygomycete, after the zygospore isformed, the next event will be

karyogamy.

4. Why does champagne have bubbles?

CO₂ is used to makeglucose during respiration.

Yeast fermentation continues afterthe champagne is bottled.

Dead yeast cells releaseCO₂ into the bottles.

Yeast produce O₂ during aerobic respiration.

5. Many antibacterial antibiotics interfere with proteinsynthesis. Why would these not be a good target for antifungaldrugs?

Fungi can rapidly metabolizedrugs.

Fungi produce few proteins.

Chitin cell walls prevent uptake ofdrugs.

Human and fungal ribosomes areextremely similar to each other.

Fungi absorb proteins during decomposition of organicmatter.

6. Which molecule would be an indicator of fungal contaminationin a drug preparation?

Deoxyribose

7. Why can lichens live on bare rock?

UV radiation powers enzymes thatallow the fungus to extract organic material from itssurroundings.

The fungi are autotrophic.

The photosynthetic endosymbiontprovides the fungus with nutrition.

They absorb heat from the sun.

They secrete acids to liberate minerals from the bare rock.

8. What type of symbiotic relationship is exemplified bymycorrhizal fungi?

Parasitism

Commensalism

Atavism

Mutualism

9. In what way are bacteria and fungi similar?

Cell wall components

Ribosome structure

Design of the nucleus

Ecological function

10. he fungal group that is most closely related to ancestralfungi are the

Zygomycota.

Basidomycota.

Ascomycota.

Chytridomycota.

11.Select the INCORRECT statement(s) concerning reproduction ofthe mold Rhizopus.

Fungal hyphae are multinucleate andhaploid.

Meiosis comes immediately beforefertilization.

The germinating zygosporangiumcontains diploid nuclei.

Rhizopus exclusivelyreproduces asexually.

Zygospores are only produced after meiosis.

12. Primary mycelia contain twice as much DNA as secondarymycelia.

True

False

13.After severe floods homeowners often return home to find thewall of their homes covered in mold. How does mold survive on wetwallboard?

It eats the gypsum that makes upthe wallboard.

Spores from within the wallboardgerminate and start growing.

It uses the wallboard as asubstrate but extracts nutrients from the air.

It digests the cellulose in the paper backing.

14. Why is the term "fungal cell mitosis" not technicallyaccurate?

The septa between nuclei form priorto mitosis.

All of the mycelium undergoesmitosis at the same time.

All stages of mitosis occur withinthe nucleus.

The mitotic spindle spans across the perforations of thesepta.

15. Select the true statements regarding the lifecycles ofbasidiomycetes and ascomycetes. (Check all that apply.)

Basidiocarps and ascocarps arefunctionally equivalent.

Dikaryotic mycelia are the same asdiploid mycelia.

Ascogenic hyphae are functionallyequivalent to secondary mycelia.

Both basidiospores and ascospores are stored externally.

16. A division of fungi that lacks septa in their hyphae exceptwhen they form sporangia or gametangia is the

	ascomycetes.
	zygomycetes.
	chytridomycetes
	basidiomycetes. PLEASE HELP

ceruleanzebra964

Fungi Fungi are the great decomposers of the biosphere. Most plants form mycorrhizae with fungi to increase absorptive area without having to grow more roots, in this relationship fungi recieve carbohydrates from plants. Humans consume fungi, mushrooms, may use fungi as a source of drugs for blood pressure, antibiotics and immunosuppresive drugs. Fungi are used in biotechnology to produce fermetation products, and some have been very useful models to study gentics in eukaryotic cells that are unicellular such as yeasts. About one third of fungi may cause infections, mycoses, in plants, animals and humans. Fungi tolerate concentration of salt and sugar that plasmolyze bacteria in perserved foods exposed to air which contains fungal spores may germinate and may spoil food. Fungi have two body shapes, molds and yeasts. Mold are large and made of long filamentous hyphae. Hyphae form mats called mycelium ( plural is mycelia). Mycelia may extend for miles underground, making fungi the largest organism on earth. The visible portion of subterrean fungi are the fruitng bodies such as mushrooms. Yeasts are globular and unicellular. They may bud forming up 24 daughter cells from a single cell. When budding is incomplete it may produce a psuedohypa. Fungi that may exist in both body types are dimorphic fungi. In general, the yeast form of a dimorphic fungus is a pathogen, the filamentous form is not pathogenic. Examples are Histoplasmosis capsulatum (histoplasmosis) and Coccidiodes immitis (coccidioidomycosis). Fungi are saprobes, they absorb nutrients from the remains of dead plants or they lasso nematodes. Fungi may derive nutrients from a living plant utilizing haustoria which are modified hyphae that penetrate living plant tissue. Some fungi use melanin to absorb gamma rays which they convert to chemical energy. Some herbivores have fungi in thier gut microbiome to help digest plants. Zygomycota contains 1100 species and reproduces asexually through sporangiaspores, which form in a sac called a sporangium on a stalk called a sporangiaphore. An example is Nosema which is an obligate intracellular parasite in insects and honeybees. Ascomycota havd 32,000 species form haploid ascospores in sacs called ascus (asci plura) and reproduce asexually with condiospores which develop on the tips of hyphae on stalks called conidiophores. Examples are Claviceps purpurea, ergot, which grows on grain and causes abortions in cattle and hallucinations in humans. Penicillium the source of the first antibiotic discovered by Fleming in the 1940s. Saccharomyces, a facultative anaerobe, ferments sugar to produce alcohol and carbon dioxide gas and is used in baking and brewing. Neurospora was used as a model to study molecular biology, Beadle and Tatum established one gene one enzyme using this model organism.

14. Why are there more antibacterial drugs than antifungal drugs? Basidiomycota have fruiting bodies called basidiocarps. Basidiospores are dispersed by the wind and germinate in warm moist environments. An example is the pathogen Cryptococcus neoformans the leading cause of fungal meningitis

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BIO 201 Lecture Notes - Lecture 23: Ascomycota, Dikarya, Hypha

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