Chapter 19, Problem 2STP

Summary Introduction

Introduction:

Euglena is a eukaryotic single-celled protist possessing flagella for locomotion. They live in freshwater and saltwater. It carries the characteristics of both plants and animals. Like plants, it has plastids through which it performs photosynthesis in the presence of sunlight.

Answer to Problem 2STP

Correct answer is option (D).

Explanation of Solution

Explanation/justification for the correct answer :

Option (D) 4. Eyespot is also called as stigma and has photoreceptors that detect light and play an important role in phototaxis. It is found in the gullet, i.e., at the base of the flagellum.

Explanation for the incorrect answer :

Option (A) 1, represents chloroplast that is used to capture sunlight and perform photosynthesis. Hence, it is an incorrect answer.

Option (B) 2, represents nucleus. Hence, it is an incorrect answer. Option (C) 3, represents contractile vacuole that functions to remove the surplus amount of water in the reservoir that is found near the base of flagella. Hence, it is an incorrect answer.