Chapter 21, Problem 3STP

Summary Introduction

Introduction :

Protists are classified more easily by what they are not than by what they are. Protists are not animals, plants, or fungi because they do not have all of the characteristics necessary to place them in any of these kingdoms.

Answer to Problem 3STP

Correct answer :

The correct answer is option (D) Sporozoans

Explanation of Solution

Explanation/justification for the correct answer :

Option (D) Sporozoans. Animal-like protists that belongs to the phylum Apicomplexa are also known as sporozoans. All sporozoans are parasitic as they get their nutritional requirements from a host organism. Sporozoans infect vertebrates and invertebrates by living as internal parasites. So, the correct answer is option (D).

Explanation for incorrect answer :

Option (A) Chrysophytes. Chrysophytes are a group of algae occurring naturally in lakes. Owing to their coloration from unique photosynthetic pigments they are often referred to as golden-brown algae. So, this is an incorrect answer.

Option (B) Dinoflagellates. Dinoflagellate, one of the single cell marine organisms with two dissimilar flagella and plant and animal characteristics. So, this is an incorrect answer.

Option (C) Sarcodines. Members of the phylum Sarcodines are animal-like protists that use pseudopods for feeding and locomotion. They are found in the genus Amoeba. Most Amoebas are found in saltwater. So, this is an incorrect answer.