Chapter 32, Problem 1RQ

Distinguish the terms in the following pairs: autotrophic and heterotrophic; phototrophic and chemotrophic; herbivores and carnivores; omnivores and insectivores.

Summary Introduction

To distinguish: The terms autotrophic and heterotrophic.

Introduction: The modes of nutrition exhibited by organisms vary from one to another. An autotrophic organism is capable of manufacturing its own food, whereas a heterotrophic organism depends on another organism to obtain its food.

Explanation of Solution

The difference between the terms autotrophic and heterotrophic has been tabulated below:

No.	Criteria	Autotrophic	Heterotrophic
1.	Definition	The organisms that are capable of manufacturing their own food from inorganic substances such as carbon dioxide and ammonia are called autotrophic.	The organisms that are incapable of producing their own food and take inorganic substances to obtain food and energy are called heterotrophic.
2.	Examples	Most of the autotrophic organisms, like green plants, certain algae, and photosynthetic bacteria, utilize light in the form of energy.	All the animals, fungi, protozoans, and most of the bacteria are heterotrophic.

Summary Introduction

To differentiate: The terms phototrophic and chemotrophic.

Introduction: Autotrophic animals have further been classified into phototrophs and chemotrophs on the basis of their source of energy.

Explanation of Solution

The contrasting features of phototrophs and chemotrophs have been summarized in the table below:

No.	Criteria	Phototrophs	Chemotrophs
1.	Definition	These organisms utilize light as the source of energy to synthesize their own food.	These organisms utilize the energy obtained through oxidation of inorganic substances to produce their own food.
2.	Mode of food synthesis	These organisms perform photosynthesis.	These organisms perform chemosynthesis.
3.	Examples	Some examples include green plants, cyanobacteria, and certain algae.	Some of the examples include sulfur-oxidizing bacteria, and iron-oxidizing bacteria.

Summary Introduction

To distinguish: The terms herbivores and carnivores.

Introduction: Heterotrophic organisms have been further categorized into different groups on the basis of the food they consume.

Explanation of Solution

The difference between the terms herbivores and carnivores has been tabulated below:

No.	Criteria	Herbivores	Carnivores
1.	Definition	The organisms which consume only green plants as food are called herbivores.	The organisms which consume meat in order to survive are called carnivores.
2.	Examples	Animals such as cow, goat, sheep (cattle), deer, bison, and yak are all herbivores.	All the apex predators like lion, tiger, and shark, are carnivores.

Summary Introduction

To differentiate: The terms omnivores and insectivores.

Introduction: The heterotrophs have also been categorized into omnivores and insectivores on the basis of the food consumed by them.

Explanation of Solution

The contrasting features of the therms omnivores and insectivores are given in the table below:

No.	Criteria	Omnivores	Insectivores
1.	Definition	The animals which are capable of consuming both meat and plants are called omnivores.	The animals which consume only insects in the form of food are called insectivores.
2.	Examples	Some common examples are humans, crow, lizards, and turtles.	The examples of insectivorous organisms are numbat, echidna, swallow, common nightingale, gecko, and chameleon.