Lecture Examination Botany 358, Fall 1998 Name_____________________________________________

I. In the space provided, place the term or process which best defines the question

___________________________A multi-nucleate mass of protoplasm without a cell wall that can creep along the substrate and has a homogeneous consistency.

___________________________A specialized kind of spore sac that produces non-motile spores in a single row.

___________________________A thick walled cell, similar to a chlamydospore, typically found between the hyphae of the heterothallic members of the Mucorales.

___________________________Type of syngamy found in the Chytridiales

___________________________Location and type of flagellum in the Hyphochytridiomycota

___________________________Process by which an organism converts its thallus entirely into reproductive structures.

___________________________The resistant structure in Allomyces, a member of the Blastocladiales

___________________________The area in the sporangium of some members of the Mucorales in which the sporangiophore is enlarged so that the sporangial wall appears confluent with the columella.

___________________________The order in which downy mildews are classified.

___________________________The order of slime molds characterized by light color spores and a pseudocapillitium.

___________________________The order in the Zygomycota that is characterized by coenocytic hyphae and hypogeous sporocarps.

___________________________The specialized size branch which produces a type of sporangium and is typical of the Kickxellales.

___________________________The structure in the hypha of the Leptomitales that makes it appear constricted.

___________________________The characteristic of the hypha that can be used to classify members of Chytridiomycota into the order Monoblepharidales

___________________________The type of sporangial apparatus typical of the Peronosporales which can either produce conidia or zoospores depending on environmental conditions

Diagram the sporangium of Pilobolus. Discuss how the sporangium is forcefully discharged and how the sporangiophore is drected towards light

 

 

 

 

 

 

 

 

 

 

 

 

Diagram the sporangial apparatus typical of the Synchephalastraceae in the Mucorales (Zygomycota)

 

 

 

 

 

 

 

 

By diagram, show where the secondary zoospores encyst and also diagram a secondary zoospore in Achlya (Oomycota, Saproleginiales).

 

 

 

 

 

 

 

Below, you will find a diagram of a zoospore of one of the organisms covered in this class. Label all parts. In which order would you classify the fungus that had this kind of zoospore?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Fill in the chart as completely as you can. However, you are to use on the space provided

Zygomycota

Oomycota

hypha

chemical compents of the cell wall

type of flagella

site of meiosis

type of resistant structure

type of mitospore

ploidy # (N, N+N, 2N) of thallus

possession of true gametes?

what structure conjugates?

type of syngamy

In Achlya

hormone responsible for syngamy

In the Mucorales:

In Achlya:

 

Discuss the adaptive value of producing coenozygospores given the following facts:

1. Coenozygospores are rarely found in nature

2. It is often difficult to find both plus and minus mating types of the same species in the same general locality in nature

3. Coenozygospores formed in the laboratory are notoriously difficult to germinate

4. Neutral strains that do not react to any sexual stimulus and never produce coenozygopores are very common in nature.

 

 

 

 

 

 

 

 

 

EITHER Define and explain the function of the sirenin in Allomyces. Include in your answer how they are used to explain flagellar movement Include in your answer the chemical pathway used to produce the hormone.

OR Define and explain the function of trisporic acid in Mucor. Include in your answer the chemical pathway used to produce the hormone.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Phylogenetically, the kingdom Stramenopila is more closely related to the Kindgom Plantae whereas the kingdom Fungi is more closely related to the Kingdom Animalia. Yet the orders in the Stramenopila (Oomycota, Hyphochytridiomycota) and in the Fungi are studied in this class. What features do these organisms possess that allowed them to be studied as fungi in the past and that allow them to be studied as a group in this class?