Biology: Protists and Their Locomotion

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Questions and Answers

What is the primary function of holdfast in multicellular organisms like kelp?

Support and anchorage (correct)

Photosynthesis

Nutrient absorption

Reproduction

Which of the following describes how fucus reproduces?

Produces only male gametes

Produces male and female gametes in separate chambers (correct)

Produces both male and female gametes in the same chamber

Reproduces asexually through fragmentation

What type of organism is referred to as a keystone species in a kelp forest?

Species that are limited to deep ocean zones

Predators that eat kelp directly

Organisms that provide habitat for many animals (correct)

Organisms with no role in the ecosystem

What characteristic distinguishes saprobic organisms?

They grow exclusively on dead organic matter Signup and view all the answers

Which of the following best describes the structure of foraminifera?

Single-celled with a shell made of calcium carbonate Signup and view all the answers

Which disease is caused by members of the genus that also produces cotton wool disease in fish?

Late blight Signup and view all the answers

What role do pseudopods play in foraminifera?

Movement and feeding Signup and view all the answers

Which nutrient source do chemoheterotrophic organisms primarily rely on?

Organic compounds from decaying matter Signup and view all the answers

What type of organisms do protists primarily consist of?

Single-celled and multicellular organisms Signup and view all the answers

What term describes the movement of organisms toward or away from light?

Phototaxis Signup and view all the answers

How do pseudopodia contribute to the movement of certain protists?

By channeling water to extend parts of the membrane Signup and view all the answers

What is the resting state of plasmodial slime molds called when conditions are poor?

Sclerotium Signup and view all the answers

Which characteristic do plasmodial slime molds share with fungi?

Being macroscopic and visible to the naked eye Signup and view all the answers

Which type of movement is associated with responsiveness to a chemical gradient?

Chemotaxis Signup and view all the answers

Which of the following is NOT a function of cilia in protists?

Absorption of nutrients Signup and view all the answers

What describes a sessile organism's behavior?

It remains fixed in place. Signup and view all the answers

What is the primary method by which Paramecium moves?

Cilia hair-like projections Signup and view all the answers

What metabolic strategy do some protists exhibit in varying environmental conditions?

Facultative autotrophic or heterotrophic Signup and view all the answers

Which organism is primarily responsible for breaking down cellulose in termite digestive tracts?

Trichonympha Signup and view all the answers

Which of the following organisms is NOT pathogenic?

Paramecium Signup and view all the answers

What is the main characteristic feature of the supergroup Excavates?

Flagella for movement Signup and view all the answers

What defines multicellular brown algae such as Fucus?

They grow in sessile forms. Signup and view all the answers

Which of the following best describes the nutritional needs of green flagellated protists?

Both autotrophic and heterotrophic based on light availability Signup and view all the answers

What is a unique characteristic of organisms from the supergroup Alveolates?

Presence of membrane-bound sacs (alveoli) under their plasma membrane Signup and view all the answers

Study Notes

Protists

Single-celled or multicellular organisms
Resemble both plants and animals
Mostly eukaryotic
Can have microtubules which form the cytoskeleton for support
Can move via cilia, flagella, or pseudopodia

Locomotion

Protists can move to achieve favorable conditions
Phototaxis: Movement towards or away from light
Chemotaxis: Movement in response to a chemical gradient
Thigmotaxis: Movement in response to touch

Plasmodial Slime Mold

A giant single-celled organism with multiple nuclei
Macroscopic, can be seen with the naked eye
Shares characteristics with fungi
Moves via pseudopods, can extend them to explore the environment
Can move towards or away from chemicals based on their needs
Forms a resting state called a sclerotinum in unfavorable conditions
Exhibits complex decision-making including identifying optimal pathways to food

Paramecium

Large single-celled organism with cilia
Has an oral groove with a pore called the cytostome for taking in food
Heterotrophic, needs to obtain food from outside sources
Not pathogenic, unlike most protists

Euglena

Flagellated, unicellular organism that lives in water
Has chloroplasts allowing for photosynthesis
Can be heterotrophic when light is scarce or autotrophic in favorable conditions.
Facultative means able to switch between different metabolic modes

Trichonympha

Unicellular, flagellated organism
Endosymbionts of termites, meaning they live within termites in a mutually beneficial relationship
Live in the termites' digestive tracts and produce enzymes called cellulases to break down cellulose in wood
Lack mitochondria, but contain other endosymbionts that produce cellulases
Some members of this supergroup cause human diseases

Fucus

Sessile, multicellular organism
Brown algae also known as kelp, distinct from plants
Has specialized structures:
- Fronds: Leaves
- Stipe: Stem
- Holdfast: Roots
Photosynthetic and grow in shallow marine areas, forming kelp forests that provide habitats for other organisms
Produces both male and female gametes in separate chambers
Used as an emulsifier and dietary supplement, also relevant for treating diseases
Kelp is a keystone species, many organisms in the kelp forest rely on it for survival

Water Mold

Chemoheterotrophic saprobic, grows on dead things and in water
Body is a mass of thread-like filaments called hyphae, a term used for fungi
Coenocytic, lacks internal cell membranes like Physarum
Produces male and female gametes
Causes various plant and animal diseases, including: - Cotton wool disease on fish - Late blight, which caused the Irish potato famine

Foraminifera

Moves via pseudopods
Chemoheterotrophic marine organisms
Biomineralized with calcium carbonate
Foraminifera uses calcium carbonate to build shells called tests
These shells contribute to the formation of deep-sea limestone

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Description

This quiz explores the fascinating world of protists, focusing on their structure, locomotion methods, and specific examples such as plasmodial slime mold and paramecium. Understand the unique characteristics that allow these organisms to thrive and adapt in various environments.