Chapter 5

Question 1

What are some traits of protists?

Answer 1

• Protists are a diverse, polyphyletic group of eukaryotic organisms.
• Protists may be unicellular or multicellular.
• They vary in how they get their nutrition, morphology, method of locomotion, and mode of reproduction.

Question 2

What are protists called during the feeding and growth part of their life?

Answer 2

Trophozoites.

Question 3

What stage do protists enter during harsh environmental conditions?

Answer 3

Encapsulated cyst stage.

Question 4

What is encystment?

Answer 4

The process by which a trophozoite becomes a cyst (cell with a protective wall).

Question 5

What is excystment?

Answer 5

Cyst to trophozoite.

Question 6

How does asexual reproduction occur in protozoans?

Answer 6

Binary fission, budding, or schizogony.

Question 7

What is schizogony?

Answer 7

The nucleus of a cell divides multiple times before the cell divides into many smaller cells.

Question 8

What are the important structures of protists?

Answer 8

Contractile vacuoles, cilia, flagella, pellicles, and pseudopodia.

Question 9

Protozoans are heterotrophic, what does heterotrophic mean?

Answer 9

An organism that cannot produce its own food and instead relies on other sources of organic carbon, mainly plant or animal matter, for nutrition.

Question 10

What is the difference between holozoic and saprozoic?

Answer 10

Holozoic: ingest whole food
Saprozoic: ingest small, soluble food molecules.

Question 11

What do protists use for locomotion?

Answer 11

whip-like flagella, hair-like cilia, or cytoplasmic extensions (pseudopodia “false feet” to attach the cell to a surface)

Question 12

What are the three supergroups?

Answer 12

Amoebozoa, chromaleolata, and excavata.

Question 13

What does helminth mean?

Answer 13

Worm

Question 14

How are helminth parasites identified?

Answer 14

By looking for microscopic eggs and larvae.

Question 15

What are the two major groups of helminth parasites?

Answer 15

Roundworms (Nematoda) and flatworms (Platyhelminthes).

Question 16

What is monecious?

Answer 16

Both male and female reproductive organs in a single individual.

Question 17

What is dioecious?

Answer 17

Having either male or female reproductive organs.

Question 18

How are nematodes transmitted?

Answer 18

Common intestinal parasites often transmitted through undercooked foods, although they are also found in other environments.

Question 19

How are platyhelminths transmitted?

Answer 19

Includes Tapeworms/Cestodes and flukes, which are often transmitted through undercooked meat. Most of them are monoecious.

Question 20

How are nematoda (roundworms) identified?

Answer 20

In feces or around the anus of infected individuals.

Question 21

What is an example of a roundworm?

Answer 21

Ascaris lumbricoides is the largest nematode intestinal parasite found in humans; females may reach lengths greater than 1 meter. It may cause symptoms ranging from relatively mild to severe.

Question 22

What is the most common Nematoda infection?

Answer 22

Pinworm (Enterobius vermicularis) that cause sleeplessness and itching around the anus.

Question 23

How many classes of flatworms (platyhelminths) are there?

Answer 23

4

Question 24

What are some characteristics of fungi?

Answer 24

• The fungi include diverse saprotrophic eukaryotic organisms with chitin cell walls.
• Can be unicellular or multicellular
• Some (like yeast) and fungal spores are microscopic, whereas some are large.
• Some pathogenic species that can cause mycoses.

Question 25

What are multicellular molds made up of?

Answer 25

Filaments called hyphae.

Question 26

What are hyphae?

Answer 26

Hyphae can form a tangled network called a mycelium and form the thallus (body) of fleshy fungi.

Question 27

What is septate hyphae?

Answer 27

Hyphae that have walls between the cells.

Question 28

What is nonseptate or coenocytic hyphae?

Answer 28

Hyphae that lack walls and cell membranes between the cells.

Question 29

How do unicellular yeasts reproduced?

Answer 29

Budding off a smaller daughter cell.

Question 30

What are the four fungal groups?

Answer 30

Zygomycota, Ascomycota, Basidiomycota, and Microsporidia.

Question 31

Which three groups produce deadly toxins?

Answer 31

Zygomycota, Ascomycota, and Basidiomycota

Question 32

What is targeted in antifungal medication?

Answer 32

Important differences in fungal cells, such as ergosterols in fungal membranes.
- Similarities in human and fungal cells can cause difficulties in finding targets and toxic effects.

Question 33

What are algae important for?

Answer 33

Producing agar, which is used as a solidifying agent in microbiological media, and carrageenan.

Question 34

Overall algae has little pathogenicity, what is the exception to this?

Answer 34

May be associated with toxic algal blooms that contaminate seafood with toxins that cause paralysis.

Question 35

What are lichens?

Answer 35

A symbiotic between a fungus and an algae.

Question 36

What kind of symbiotic are lichens?

Answer 36

Controlled parasitism where the fungus benefits and the algae is harmed.

Question 37

What are some traits of lichens?

Answer 37

• slow growing and can live for centuries in a variety of habits.
• environmentally important, helping to create soil, providing food, and acting as indicators of air pollution.