Chapter 12: The Eukaryotes: Fungi, Algae, Protozoa, and Helminths

Schizogony

is multiple fission; the nucleus undergoes multiple divisions before the cell divides.

T vaginalis

Like some other flagellates, has an undulating membrane, which consists of a membrane bordered by a flagellum.

chlamydoconidium

A(n) is a thick- walled spore formed by rounding and enlargement within a hyphal segment.

lichen

A(n) is a combination of a green alga (or a cyanobacterium) and a fungus.

diploid zygote

The (+) and-) (nuclei fuse to form a(n) nucleus.

Arthropods

that carry pathogenic microorganisms are called vectors.

Yeasts

are nonfilamentous, unicellular fungi that are typically spherical or oval.

amebae move

The by extending blunt, lobelike projections of the cytoplasm called pseudopods.

lichens thallus

The , or body, forms when fungal hyphae grow around algal cells to become the medulla.

Dinoflagellates

are unicellular algae collectively called plankton, or free- floating organisms.

protozoa

Some produce gametes (gametocytes), which are haploid sex cells.

Eugle

- noids have a semirigid plasma membrane called a pellicle, and they move by means of a flagellum at the anterior end.

Thalli

of the larger multicellular algae, those commonly called seaweeds, consist of branched holdfasts (which anchor the alga to a rock), stem- like and often hollow stipes, and leaflike blades.

small particulate

The feeding and growing stage, or trophozoite, feeds upon bacteria and nutrients.

Euglenoids

are photoautotrophs.

zygospore

A(n) is a large spore enclosed in a thick wall.

tachyzoites

The trophozoites, called , reproduce sexually and asexually in an infected cat, and oocysts, each containing eight sporozoites, are excreted with feces.

diploid nucleus

The gives rise to haploid nuclei (sexual spores), some of which may be genetic recombinants.

Adult helminths

may also be monoecious, or hermaphroditic- one animal has both male and female reproductive organs.

Conidia

formed by the fragmentation of a septate hypha into single, slightly thick- ened cells are called arthroconidia.

Males

are smaller than females and have one or two hardened spicules on their posterior ends.

Seasonal changes

in nutrients, light, and temperature cause fluctuations in algal populations; periodic increases in numbers of planktonic algae are called algal blooms.

ciguatera

A disease called occurs when the dinoflagellate Gambierdiscus toxicus (GAM- be ̄- er- dis- kus TOKS- i- kus) passes up the food chain and is concentrated in large fish.

Fungus

are important in the food chain because they decompose dead plant matter, thereby recycling vital elements.

Fungal hyphae

also form a cortex, or protective covering, over the algal layer and sometimes under it as well.

Paramecium

The ciliates, such as , reproduce sexually by conjugation, which is very different from the bacterial process of the same name.

Spicules

are used to guide sperm to the females genital pore.

blood parasites

The hemoflagellates () are transmitted by the bites of blood- feeding insects and are found in the circulatory system of the bitten host.

plasmodial slime mold

A(n) exists as a mass of protoplasm with many nuclei (it is multinucleated)

Any fungal infection

is called a mycosis.

Fission yeasts

, such as Schizosaccharomyces, divide evenly to produce two new cells.

Slime molds

are closely related to amebae and are placed in the phylum Amoebozoa.

Helminths

are multicellular eukaryotic animals that gener- ally possess digestive, circulatory, nervous, excretory, and reproductive systems.

Fungi

that infect only the epidermis, hair, and nails are called dermatophytes, and their infections are called dermatomycoses or cutaneous mycoses.

Fungal hyphae project

below the lichen body to form rhizines, or holdfasts.

fungal sexual spore results

A(n) from sexual repro- duction, which consists of three phases:

Subcutaneous mycoses

are fungal infections beneath the skin caused by saprophytic fungi that live in soil and on vegetation.

Dinoflagellates

in the genus Alexandrium produce neurotoxins (called saxitoxins) that cause paralytic shellfish poisoning (PSP)

Arthropods

are animals characterized by segmented bodies, hard external skeletons, and jointed legs.

Conidia

are produced in a chain at the end of a conidiophore.

Adult helminths

may be dioecious; male reproductive organs are in one individual, and female reproductive organs are in another.

Plasmodial slime molds

were first scientifically reported in 1729.

plasmodial slime molds

When are grown in laboratories, a phenomenon called cytoplasmic streaming is observed, during which the protoplasm within the plasmodium moves and changes both its speed and direction so that the oxygen and nutrients are evenly distributed.