Introduction to Protozoa and Protists

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Questions and Answers

Which organelle do flagellates primarily use for movement?

Shell

Pseudopods

Cilia

Flagella (correct)

Which type of protozoan is characterized by the use of cilia for movement?

Dinoflagellates

Ciliates (correct)

Amoebas

Forams

What is the main role of slime molds in their ecosystems?

Decomposers and recyclers of nutrients (correct)

Formation of toxic blooms

Predators of marine organisms

Producers of phytoplankton

What distinguishes foraminifera (forams) from other protozoans?

Secretion of a shell and extension of pseudopodia Signup and view all the answers

Which characteristic is unique to choanoflagellates compared to other protozoans?

Use of a flagellum surrounded by an elaborate collar Signup and view all the answers

Which of the following statements about dinoflagellates is accurate?

They can be bioluminescent and form toxic blooms. Signup and view all the answers

In the life cycle of cellular slime molds, what occurs when food becomes scarce?

They aggregate and form a multicellular structure. Signup and view all the answers

Which characteristic do amoebas possess that allows them to move?

They extend pseudopodia. Signup and view all the answers

What is a characteristic feature of diatoms?

They have a glassy cell wall made of silica. Signup and view all the answers

Which phylum includes organisms that have a notochord, dorsal hollow nerve cord, and post-anal tail?

Chordata Signup and view all the answers

Which is true regarding amphibia?

They have limbs that support weight on land. Signup and view all the answers

What describes the body plan of platyhelminthes?

They are acoelomates with bilateral symmetry. Signup and view all the answers

Which characteristic is associated with arthropoda?

They possess a rigid exoskeleton made of chitin. Signup and view all the answers

How do nematodes differ from other related phyla?

They have a complete digestive system. Signup and view all the answers

Which of the following defines the cephalopods within Mollusca?

They exhibit highly developed nervous systems. Signup and view all the answers

Which class includes jawless fish?

Agnatha Signup and view all the answers

What significant adaptation do reptiles have over amphibians?

They have hard-shelled eggs. Signup and view all the answers

Which organism is a member of the subphylum Urochordata?

Tunicates Signup and view all the answers

Study Notes

Protozoa

Flagellates: Move using flagella (whip-like organelles). Unicellular.
Ciliates: Move using cilia (tiny hair-like organelles). Alveolates. Similar structure to eukaryotic cilia.
Amoebas: Move using pseudopods (temporary extensions). Unicellular, adaptable shape. Found in various water bodies; can cause illness.
Forams: Marine protozoa. Secretes shell. Extends pseudopodia (extensions) through pores.
Choanoflagellates: Closest living relatives to animals. Unicellular predators. Use flagella surrounded by a collar for movement and hunting.

Fungus-like Protists

Slime Molds: Fungus-like protists. Key decomposers/recyclers. Found on decaying matter. Diet consists of bacteria.
Cellular Slime Molds: Protists with unicellular amoeboid cells. Form multicellular structures (slug-like) during food shortages. Develop fruiting bodies for spore dispersal.

Algae

Dinoflagellates: Protists forming "blooms." May be toxic. Can be bioluminescent. Two flagella; half heterotrophic, half photosynthetic. Mostly marine plankton.
Diatoms: Unicellular photosynthetic algae. Glassy silica cell walls. Thousands of types; two main shapes: pennate (cigar/pen-shaped) and centric (disk/drum-shaped).
Green Algae: Photosynthetic protists. Unicellular, colonial, or multicellular. Chlorophyll a & b (green colour). Store carbohydrates as starch. Cell walls are cellulose. Closest algal relatives to plants.

Animal-like Protists (Porifera)

Sponges (Porifera): Sessile, suspension feeders. No body symmetry. Flagellated collar cells (choanocytes).

Animal Phyla

Cnidaria

Cnidarians: Radial symmetry. Sessile or motile (jellyfish, anemones, corals). Cnidocytes (stinging cells). Medusa (free-swimming) and polyp (sessile) forms.

Platyhelminthes

Flatworms: Bilateral symmetry. Acoelomates (no body cavity). Incomplete digestive system (one opening). Parasitic flatworms (tapeworms) have a scolex (hooks and suckers).

Annelida

Segmented Worms: Segmented bodies. True coelom. Bilateral symmetry. (leeches).

Nematoda

Roundworms: Pseudocoelomates (body cavity partially lined with mesoderm). Complete digestive tract (two openings).

Mollusca

Mollusks: Bilateral symmetry. Gastropods (snails), bivalves (clams), cephalopods (octopuses).

Arthropoda

Arthropods: Segmented bodies. Jointed appendages. Exoskeleton made of chitin. Compound eyes (mosaic vision). Molting. Arachnids (spiders), crustaceans (crabs), insects.

Echinodermata

Echinoderms: Larvae have bilateral symmetry; adults have radial symmetry. Water vascular system. Capable of regeneration. Sea stars, sea urchins, sea cucumbers, and sand dollars.

Chordata

Chordates: Notochord, dorsal hollow nerve cord, pharyngeal slits, post-anal tail.
Urochordates: Tunicates.
Cephalochordates: Lancelets.
Vertebrates: Complex internal skeleton.

Agnatha (Jawless Vertebrates)

Jawless Fish: Hagfish and lampreys. Cartilage skeleton. Cylindrical body. No fins.
Hagfish: Primitive. Scavengers. Slimy.
Lampreys: Vertebrates without hinged jaws. Adults are often parasitic.

Chondrichthyes (Cartilaginous Fish)

Cartilaginous Fish: Flexible skeletons. Predators. Powerful jaws.

Osteichthyes (Bony Fish)

Bony Fish: Swim bladder for buoyancy control. Bone skeleton. Protected by an operculum.

Amphibia

Amphibians: First tetrapods (four limbs). Limbs support weight on land. Carnivorous. Primarily water-dwelling or damp habitats. Salamanders, frogs.

Reptilia

Reptiles: Lizards, snakes, crocodiles, turtles. Ectothermic (cold-blooded). Scales present

Reptilia/Aves (Birds)

Birds: Endothermic (warm-blooded). Feathers. Good vision. Courtship displays. Hard-shelled eggs.

Mammalia

Mammals: Mammary glands. Hair/fur. High metabolic rate. Long parental care. Usually give birth to live young. Endothermic. Teeth vary in shape.

Hominins

Hominins: Bipedal. Homo
- Homo habilis: "handy man," first tool use.
Homo erectus: Upright posture. Larger brain, face. Speech possible.

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Description

Explore the fascinating world of protozoa and fungus-like protists through this quiz. Learn about different categories such as flagellates, ciliates, and slime molds, along with their unique characteristics and ecological roles. Test your knowledge on these important microorganisms and their impact on the environment.