Living Organisms and Their Characteristics - Class 6 Notes & Olympiad Questions

Introduction

a) The term "environment" encompasses everything that surrounds us, including both living and non-living things.
b) Living organisms like plants, animals, and microorganisms are known as the biotic components of the environment.
c) On the other hand, non-living things such as air, water, rocks, soil, and light make up the abiotic components of the environment.
d) The place where plants and animals live is referred to as their habitat. It's possible for multiple species of plants and animals to share the same habitat.
e) Adaptation is the presence of specific features, body structures, or characteristics that enable an organism to survive in its habitat. Organisms develop these adaptations over time in response to the conditions of their environment.
f) Acclimatization, on the other hand, refers to certain changes that occur in an organism over a short period of time. These changes help the organism adjust to the variations in its environment. It allows the organism to cope with new or different conditions, ensuring its survival and well-being.

Interactions among Biotic Components

Ecosystems are composed of biotic components, which include all living organisms within a particular habitat.
These organisms can be broadly classified into three categories: producers, consumers, and decomposers.

Producers

a) Producers are primarily plants, algae, and certain bacteria that use sunlight through photosynthesis to convert carbon dioxide and water into energy-rich organic compounds.
b) By doing so, producers not only provide sustenance for themselves but also generate the energy necessary for other organisms to survive.

Consumers

a) Consumers, also known as heterotrophs, are organisms that depend on producers and other consumers for their energy requirements.
b) Consumers can be further divided into primary, secondary, and tertiary consumers.
c) Primary consumers, such as herbivores, directly feed on producers, while secondary and tertiary consumers feed on other consumers.
d) These interconnected feeding relationships form intricate food webs within ecosystems.

Decomposers

a) Decomposers play a vital role in ecosystems by breaking down organic matter and returning essential nutrients back into the environment.
b) These organisms, including bacteria and fungi, feed on dead plants and animals, as well as waste materials, completing the cycle of life.
c) Decomposers also play a crucial role in the process of decomposition, which contributes to nutrient recycling and the overall health of ecosystems.

Types of Interactions among Biotic Components

Biotic components in ecosystems are not isolated entities but are interconnected through a web of interactions.
These interactions can be classified into three main types: competition, predation, and symbiosis.

Competition

a) Competition arises when organisms compete for limited resources, such as food, water, and shelter.
b) In this struggle for survival, individuals with superior adaptations or access to resources gain an advantage, while others may face challenges.

Predation

a) Predation involves the consumption of one organism (the prey) by another organism (the predator).
b) Predators play a crucial role in maintaining ecological balance by controlling the population of prey species.

Symbiosis

a) Symbiotic relationships exist when two or more types of organisms interact with each other over an extended period.
b) There are three types of symbiotic relationships: mutualism, commensalism, and parasitism.
c) Mutualism benefits both kinds of animals involved, commensalism benefits one kind without harming the other, and parasitism benefits one type of organism at the expense of the other.

Abiotic Components and their Interactions with Biotic Components

a) Abiotic components are the non-living factors that shape ecosystems.
b) These include sunlight, temperature, water, air, soil, and minerals. Abiotic factors influence the distribution, abundance, and behaviour of biotic components.
c) For instance, sunlight is essential for photosynthesis, providing energy for producers to synthesise food. Water availability impacts the survival of all organisms, and soil composition determines the types of plants and microorganisms that can thrive in an area.

Characteristics of Living Organisms

Living beings, also known as organisms, are entities that possess the characteristics of life. These characteristics set them apart from non-living things. These characteristics include:

Cells: Living beings are made up of cells, which are the building blocks of life. Cells are tiny structures that carry out various functions necessary for an organism's survival.

Food: Living organisms require a source of energy, obtained through consuming other organisms or organic matter.

Growth: Living beings undergo growth and development, increasing in size and complexity over time.

Respiration: Organisms engage in respiration, a process that involves taking in oxygen and releasing carbon dioxide to produce energy.

Responding to Stimuli: Living beings can detect and respond to changes in their environment through various senses.

Reproduction: Living organisms possess the ability to reproduce, ensuring the continuity of their species.

Excretion: Waste products resulting from metabolic processes are excreted from living organisms.

Movement: Many living organisms are capable of movement, whether it be locomotion or movement of body parts.

Adaptation: Living beings can adapt to their environment over time. They possess traits and characteristics that help them survive and thrive in their specific habitats.