Biology Chapter 18: Protists Quiz

Questions and Answers

Are protists prokaryotic or eukaryotic?

eukaryotic

How were protists biologically classified?

Traditionally divided into plant-like and animal-like forms.

How are protists classified today?

As a diverse assemblage of plant-, animal-, and fungus-like groups.

What are some of the important functions that protists perform to contribute to human life?

Medicines for high blood pressure, digestion problems, ulcers, and arthritis; used in scientific studies and valuable in industry. Signup and view all the answers

Why are protists so important to evolutionary biologists?

They are key to understanding the endosymbiosis theory of evolution. Signup and view all the answers

Describe the endosymbiont theory.

It explains the dependency between a host cell and ingested bacteria, leading to a permanent relationship. Signup and view all the answers

What are algae?

Simple nonflowering plants including seaweeds and many single-celled forms. Signup and view all the answers

List some of the basic characteristics of the different types of algae.

Eukaryotic, no roots/stems/leaves, contain chlorophyll, unicellular algae are most frequent in water. Signup and view all the answers

Describe the euglenoids in terms of structure and function.

They can be autotrophic (photosynthesize) or heterotrophic (ingest food) and have chloroplasts for photosynthesis. Signup and view all the answers

Are euglenoids heterotrophs or autotrophs?

Both heterotrophs and autotrophs. Signup and view all the answers

Why are dinoflagellates known as whirling cells?

Because the term 'dinoflagellate' means 'whirling flagella'. Signup and view all the answers

Describe red tide and the connection to the dinoflagellates.

Red tides result from a rapid increase in dinoflagellate populations, discoloring the water. Signup and view all the answers

Compare and contrast the golden algae, diatoms, and brown algae.

Diatoms are known as 'Jewels of the Sea', possessing intricate designs and photosynthetic capabilities. Signup and view all the answers

Study Notes

Protists Overview

Protists are eukaryotic organisms, distinguishing them from prokaryotic bacteria.
They can be unicellular or multicellular and do not have highly specialized tissues.

Classification of Protists

Traditional classification split protists into plant-like and animal-like groups.
Current classification recognizes protists as a diverse array that includes plant-, animal-, and fungus-like organisms.

Importance of Protists

Protists contribute to human life through various applications in medicine, including treatments for high blood pressure, digestive issues, ulcers, and arthritis.
They play significant roles in scientific research and industrial applications.

Evolutionary Significance

Protists are crucial for evolutionary biology, particularly the endosymbiosis theory, which explains how eukaryotic cells evolved with chloroplasts and mitochondria.

Endosymbiont Theory

This theory posits that a large host cell and ingested bacteria formed a symbiotic relationship, leading to mutual dependence.
Over time, mitochondria and chloroplasts became specialized and could no longer survive independently.

Algae Characteristics

Algae are simple, non-flowering plants including seaweeds and unicellular forms.
They contain chlorophyll and perform photosynthesis but lack true roots, stems, and leaves.

Types of Algae

Eukaryotic organisms, algae do not have roots, stems, or leaves but possess chlorophyll for photosynthesis.
Unicellular algae primarily exist in water environments, especially planktonic forms.

Euglenoids Structure and Function

Euglena are mixotrophic protists capable of both photosynthesis (autotrophic) and ingestion of food (heterotrophic).
They utilize chloroplasts for photosynthesis and exhibit locomotion through flagella and a flexible pellicle membrane.

Euglenoid Nutrition

Euglenoids can be considered heterotrophs since they consume food but also possess the ability to photosynthesize, thanks to chloroplasts.

Dinoflagellates

The term "dinoflagellate" signifies "whirling flagella," reflecting their motility.
Known for significant population blooms, which can lead to phenomena like red tides.

Red Tide Phenomenon

Red tides occur when dinoflagellate populations grow excessively, discolored due to high concentrations of cells.
Environmental conditions driving these blooms remain only partially understood, but can reach densities of 20 million cells per liter.

Comparing Algae Types

Diatoms are yellow or golden-brown algae, known as "Jewels of the Sea," recognized for their intricate and beautiful cell walls.
Brown algae and golden algae also exhibit photosynthetic capabilities, with distinct characteristics differentiating them from diatoms.

Description

Test your knowledge on the kingdom Protista with these flashcards. The quiz covers definitions, classification, and characteristics of protists, including their eukaryotic nature. Perfect for revising the key concepts from Chapter 18.