In mid December, a woman with insulin dependent diabetes which had been in prednisone fell and received an abrasion on the dorsal side of her right hand. She was placed on penicillin. By the end of January, the ulcer had not healed, and she was referred to a plastic surgeon. On January 30, a swab of wound was cultured at 35 degrees on agar. On the same day, a smear was made for gram staining. Slid cultures set up on February 1 and incubated at 25 degrees showed septate hypae and single conidia. The most likely cause of the infection is a

dimorphic fungus

which of the following tends to be more complex in a parasitic helminth than in a free living helminths

reproductive system

Which of the following is false

fungal spores are highly resistant to heat and chemical agents

helminthic diseases are usually transmitted to humans by

gastrointestinal route

All of the following are characteristic of the platyhelminthes except that they

have highly developed digestive and nervous systems

in the malaria parasite life cycle, humans are the ____ host, while mosquitoes are the ___ host as well as the vector

intermediate; definitive

Three weeks after a river rafting trip, three family members experienced symptoms of coughing, fever, and chest pain. During the rafting trip, the family had consumed crayfish that they caught along the river banks. An examination of the patients' sputum revealed helminth eggs, and serum samples were positive for antibodies to Paragonimus. All of the family members recovered following treatment with praziquantel. In the Paragonimus life cycle,

Humans are the definitive host and crayfish are the intermediate host

The encysted larva of the beef tapeworm is called

cysticercus

Which of the following arthropods does not transmit diseases by sucking blood from human host

houseflies

a definitive host harbors which stage of a parasite

adult

what do tapeworms eat

intestinal contents

Giardia and Trichomonas are unusual eukaryotes because they

lack mitochondria

The life cycle of the fish tapeworm is similar to that of the beef tapeworm. Which of the following is the most effective preventive measure?

cooking fish before eating

Which of the following is the most effective control for malaria

eliminate Anopheles mosquitoes

In the microscope, you observe multinucleated amoebid cells with sporangia that form spores. This is a

plasmodial slime mold

Which of the following pairs is mismatched

cestodes - all are free living

which of the following is a nucleated, unicecullar organism that, if you changed the incubation temperature, would form filaments with conidiospores

ascomycete

which of the following organisms is photoautotrophic protozoan

Euglena

if a larva of Echinococcus granulosus is found in humans, humans are the

intermediate host

ringworm is caused by

fungus

yeast infections are caused by

candida albicans

plasmogamy, karyogamy, and meiosis are stages of the fungal sexual life cycle

true

arthropod vectors are blood sucking animals such as ticks, lice and fleas that transmit microbial pathogens

true

cercariae, metacercaria, redia, and sporocysts are all life cycle stages of trematodes

true

the platyhelminths group includes roundworms, tapeworms, and flukes

false

some species of dinoflagellates produce neurotoxins that cause fish kills and red tides.

true

both the cellular slime molds and the plasmodial slime molds are members of the phylum amoebozoa

true

In helminth life cycles, the organism that harbors the adult sexually reproductive phase of the parasite is called the intermediate host.

false

The sporozoite, merozoite, gametocyte, and ring stages are all part of the Plasmodium life cycle.

true

The insect vectors have six legs and include spiders, ticks, mosquitoes, and lice.

false

Most cases of hookworm infection are acquired by ingestion of adult forms in contaminated food or water.

false

Protozoa are unicellular, eukaryotic chemoheterotrophs

true

organisms belonging to apicomplexa are plasmodium and cryptosporidium

true

Parasitic flatworms belong to the Phylum Nematoda and Parasitic roundworms belong to the Phylum Platyhelminthes

false

The adult stage of a parasitic helminth is found in the definitive host

true

The nematodes that infect humans with their larvae include Ancylostoma duodenale and Trichinella spiralis

true

Fungi are aerobic or facultatively anaerobic chemoheterotrophs

true

Zygospores are produced asexually

false

the portion of a hypha that obtains nutrient is called the aerial hypha

false

the cestode, or tapeworm, consists of the scolex and proglottids

true

tapeworms and flukes are similar due to their incomplete digestive system and larval stage

true

protozoan and helminthic diseases are difficult to treat because

their cells are structurally and functionally similar to human cells

Which of the following tends to be more complex in a parasitic helminth than in free living helminths

reproductive system

helminthic diseases are usually transmitted to humans by

gastrointestinal route

which of the following is not a characteristic of parasitic platyhelminths

They have a complete digestive system

cercariae, metacercaria, miracidia, and rediae are stages in the life cycle of

nematodes

the encysted larva of the beef tapeworm is

cysticercus

which of the following arthropods does not transmit diseases by sucking blood from human host

houseflies

what is common between cestodes and trematodes

cuticle

which of the following pairs is mismatched

lice - pneumocystis

which of the following statements is false

fungal spores are resting spores to protect the fungus from adverse environmental conditions

which of the following pair is mismatched

sporangiospore - formed within hyphae

chlamydoconidium - formed in a sac

which of the following is not a characteristic of parasitic platyhelminths

they have a complete digestive system

what do tapeworms eat

intestinal contents

The lifestyle of the fish tapeworm is similar to that of the beef tapeworm.Which of the following is the most effective preventive measure

cooking fish before eating

multinucleated amoebalike cells that produce funguslike spores

plasmodial slime mold

amoebalike vegetatie structures that produce sporangia

cellular slime mold

a multicellular organism; the digestive tract has one opening

tapeworm

an organism that can grow photoautotrophically in the light and chemoheterotrophically in the dark

euglena

the cells of plasmodial slime molds can grow to several centimeters in diameter because

they distribute nutrients by cytoplasmic streaming

ringworm is caused by

ascomycete

why are fungal colonies described as vegetative structures?

because they're composed of the cells involved in catabolism and growth.

what is the thallus

it is the body which consist of long filaments

hyphae

long filaments which contains septa

septa

divides fungi into distinct, uninucleate cell-like units.

conenocytic hyphae

long continuous cells with many nuclei

vegetative hypha

portion of the hypha that obtains nutrient

aerial hyphae

concerned with reproduction

fission yeasts

divides evenly to produce two new cells. parent cell elongates, nucleus divides and 2 offspring cells are produced.

capable of facultative anaerobic growth.

dimorphic fungi

can grow either as mold or yeast

life cycle of fungi

filamentous fungi can reproduce asexually by fragmentation of the hyphae

spores

formation of fungi reproduction, both sexually and asexually

asexual spores

formed by the hyphae of one organism. produced through mitoses and cell division

condiospore

unicellular or multicellular spore that is not enclosed in a sac

conidia/conidiophore

asexual spore

conidia are produced in a chain at the end of conidiophore

sporangiospore/sporangiophore

asexual spore

sporangiospore is formed within a sporangium

sexual spore

results from sexual reproduction

3 stages: phasmogamy, karyogamy, meiosis

phasmogamy

haploid nucleus of donor cells (+) penetrates the cytoplasm of recipient (-)

karyogamy

the (+) and (-) nuclei fuse to form a diploid zygote nucleus

Meiosis

diploid give rise to haploid nuclei

mycosis

fungal infection. it is classified into five groups based on degree of tissue involvement and mode of entry into the host

systemic mycoses

fungal infection deep within the body. It is caused by fungi that live in the soil, it is spread by inhalation

subcutaneous mycoses

fungal infections beneath the skin. It is caused by saprophytic fungi that live in soil and vegetation. Occurs by direct implantation into a wound

cutaneous mycoses

fungi that only infect epidermis, hair, and nails. transmitted by direct contact with infected areas

superficial mycoses

localized along hair shafts and in superficial epidermal cells

opportunistic pathogen

generally harmless in its normal habitat but can become pathogenic in a host who is seriously traumatized.

protozoa

unicellular eukaryotes and inhabits water and soil

mostly aerobic heterotrophs and live in areas with large supply of water

what is the stage of feeding of protozoa called what do they feed upon

trophozoite. They feed upon bacteria and small particle nutrients

life cycle of protozoa

they reproduce asexually by fission, budding or schizogony

what is schizogony

multiple fission. Nucleus undergoes multiple divisions before cell divides

cyst

protective capsule that protozoa produce in adverse conditions.

it permits the organism to survive when food, moisture or oxygen are lacking, temperature are not suitable, or when toxic chemicals are present.

oocyst

cyst formed in members of the phylum apicomplexa.

a reproductive structure in which new cells are produced asexually.

Euglenozoa

2 groups based on rRNA sequences, disk-shaped mitochondria, and absence of sexual reproduction. Euglenoids and hemoflagellates

Amebae

move by extending blunt, lobelike projections of pseudopods

entamoeba histolytica

only pathogenic ameba found in human intestine.

causes dysentery

uses lectin to attache to galactose of plasma membrane and causes cell lysis

aplicomplexa

not motile in their mature forms.

obligate intracellular parasites

sporozoite

an anopheles carrying the infective stage of plasmodium m

merozoites

what is produced when sporozoites undergo schizogony

what is the ring stage

when young trophozoite looks like a ring in which nucleus and cytoplasm are visible.

definitve host

harbors the sexual reproducing stage of plasmodium

intermediate host

host in which the parasite undergoes asexual reproduction

what are the two phyla of helminths

platyhelminths (flatworms)

nematodes (roundworms)

what are some of the characteristics of helminths

they are multicellular eukaryotic animals

they may lack digestive system

their nervous system is reduced

their means of movement is reduced or lacking

reproductive system often complex

larval

developmental stage of parasites

dioecious

male reproductive organs are in one individual while the female reproductive organ is in another

monoecious/hermaphroditic

one animal has both male and female reproductive organs

trematodes (Flukes)

have flat, leaf-shaped bodies with ventral sucker and oral sucker. obtain food by absorbing it thought their cuticle

paragonimus

lung fluke.

occurs through the world

cestodes (Tapeworm)

interstinal parasite.

they lack a digestive system and absorb food through their cuticle

taenia saginata

the beef tapeworm, lives in humans.

taenia solium

pork tapeworm

humans are the only definitive host

echinococcus granulosus

humans are the intermediate hosts

nematodes

roundworms

they have complete digestive system

the males are smaller than the females

ascaris lumbricoides

a large nematode.

it is dioecius with sexual diphormism

define sexual dephormism

the male and female worms look distinctly different, the male being smaller with a curled tail

ancylostoma duodenale

live in the small intestine of humans. eggs are excreted in feces.

how does a larva enter its host

it penetrates the host's skin. it enters the blood or lymph vessel which carries it to the lungs.