Unit 3 Homework

What is the transmission method of Enterobius vermicularum?

transfer of eggs from anal area to mouth by fingers

The incidence of the disease _____ is very high in Alaska, due to the ingestion of contaminated bear and seal meat.

trichinellosis

When studying the four basic helminth life cycles, it is apparent that the egg larval stage of the worm has to be picked up by an intermediate host or develop in soil before it can infect humans.

true

Fungi

Eukaryotes which can be either unicellular or multi-cellular; multi-cellular forms include mushrooms

Helminths

Eukaryotes whose adult form are always multi-cellular

Select all of the correct answers in this question to test your understanding of the general characteristics of viruses.

-Lytic viral infection often results in destruction of the host cell. -The nucleic acids of certain animal viruses are composed of DNA whereas others are composed of RNA. -Viruses are composed of DNA or RNA molecules surrounded by a protein coat.

All of the following pertain to tapeworms?

-cysticerci are young infective larvae ingested in undercooked meat. - strobila is made up of proglottids. -scolex is the head. -proglottids are reproductive segments.

Which of the following is not an effective way to minimize human contact with parasitic helminths?

-freezing foods -proper sewage disposal -avoiding human feces as fertilizer - thoroughly cooking foods

Parasitic helminthes have the following characteristics

-have a definitive host where the adult form lives -are multicellular animals - include tapeworms -include roundworms

Hookworms

-include Necator americanus. - include Ancylostoma duodenale. - have oral cutting plates by which they anchor to the intestines. - have filariform larvae in soil that get transmitted into bare feet.

Ascaris lumbricoides

-larvae penetrate into lymphatics and capillaries around intestines. -spreads to humans by ingestion of Ascaris eggs in food. -larvae migrate to the pharynx, get swallowed, and return to intestines to mature. - is an intestinal roundworm.

Trichinosis includes all the following?

-migrate from intestines to blood and various body tissues. -encysted larvae get ingested. - associated with undercooked pork or bear meat. - the first symptoms are diarrhea, nausea, fever, and pain.

Transmission of tineas include?

-soil to human -human to human -animal to human -fomites to human

How many basic life and transmission cycles do helminths have?

4

Animal viruses are classified based upon the nature of their nucleic acids, the shape of their _____, and whether or not they possess a viral _____

Capsid, envelope

Protozoa

Eukaryotes which are always unicellular

Algae

Photosynthetic eukaryotes which can be either unicellular or multi-cellular; multi-cellular forms include seaweed

Which of the following causes serious congenital disease from transplacental transmission?

Toxoplasmosis

T/F In temperate zones, pinworms are the most common helminth infection.

True

Please select the correct feature that is specific for Taenia solium, but not Taenia saginata.

can encyst within the brain

The larval forms of certain Taenia species, which typically infest muscles of mammalian intermediate hosts is also called a

cysticerci.

What is the transmission method of Trichinella spiralis?

eating contaminated pork

The two major groups of parasitic helminths include the ____ with a thin, segmented body and the _____ with a cylindrical, unsegmented body.

flatworms, roundworms

Eggs and larva are developmental forms of various parasites called _____.

helminths

What is the transmission method of Ascaris lumbricoides?

ingested eggs coming from contaminated soil

What is the transmission method of Necator americanus?

walking barefoot in contaminated soil