The Living Organisms – Characteristics and Habitat

What are Living Organisms?

These are things such as plants, animals, and microscopic organisms that have characteristics shared with others such as growth, movement, & reproduction. They inhabit distinct habitats or environments.

Habitat and Adaptations

What is a Habitat?

This is the area where an organism lives in a natural environment. It is the supply of food, water, shelter & proper conditions to survive.

Types of Adaptations

Adaptations are traits that help organisms thrive in their environments. These adaptations can be:

• Structural Adaptations – These are the physical features of an organism. For instance, polar bears have long fur to keep them warm.
• Behavioral Adaptations – Things they do such as some birds migrate south in winter.
• Physiological Adaptations – Internal physical processes, like with a camel storing water.

Example: Fish have gills, which extract oxygen from water — this is a feature we expect given their habitat.

 

Types of Organisms Based on Habitat

Living organisms are classified into five major groups based on habitat:

1. Terrestrial organisms (land-dwelling)

2. Aquatic organisms (water-dwelling)

3. Amphibians (live both on land & in water)

4. Aerial organisms (primarily fly)

5. Arboreal organisms (live mostly on trees)

 

Key Points to Remember

• They can grow, move, respire, reproduce, excrete & respond to stimuli.

• The whole biogeochemical cycle is feedback between an organism (who exchanges information with the environment around it) & its habitat.

• Adaptations can help organisms survive in different environments.

• Habitats can be terrestrial, aquatic, arboreal, or amphibious.

 

Practice Questions:

• Identify characteristics of the organisms in the examples.
• Identify these animals in their natural habitat.
• Explain how certain animals live in their environment.

 

What are Living Organisms?

Microorganisms show signs of life, being living plants, animals, and microorganisms, showing growth, reproduction, adaptation, etc. Non-living things, on the other hand, do not need food, water, and air to survive.

 

Characteristics of Living Things

5 Fundamental processes that are associated with life- Living organisms show some basic features and these processes are either absent or are minimal in non-living forms.

All cells reproduce, respond to stimuli, metabolize nutrients (and excrete waste), and grow, so all living things share these characteristic functions: (1) cellular organization, (2) nutrition, (3) growth, (4) respiration, (5) movement, (6) responsiveness, (7) excretion, (8) reproduction, & (9) life cycle.

1. Cellular Organization

Cells are the building block of life from which all organisms are formed. Cells perform basic processes such as digestion, respiration & excretion. Organisms are categorized based on the number of cells they contain:

• Unicellular organisms – consist of a single cell that carries out all necessary life functions. Including some amoeba, paramecium, euglena, yeast, bacteria, etc.

• Multicellular organisms – Composed of many cells that coordinate with each other to sustain life. Plants, sponges, octopuses, ants, & cats, say.

2. Nutrition

Food is any substance eaten to provide nourishment to the body for survival, growth, endorsement, & development of every organism.

• Autotrophic Nutrition – The green plants make their own food from carbon dioxide, water, sunlight & chlorophyll through a process called photosynthesis.

• Heterotrophic Nutrition – Since animals consume plants and other animals, they are heterotrophs Some eat plant materials (herbivores), some eat animal material (carnivores), & some eat both (omnivores).

3. Growth

Thus a growing period can be specified for living things that have developed irreversibly in their size & development

• As a matter of course, the descendants of organisms grow into adults; a human fetus matures into an adult human or a seed grows into a plant.

• More of mammals & reptiles (and bird some here) can only grow Out up to a certain age (like humans: stop between 18 & 30 yo) — they won’t keep growing through its lifetime (even with the ‘most humans aren’t mammals’ loophole), and only tree do.

4. Respiration

Respiration is the biochemical process by which food is broken down to release energy. This energy is subsequently employed for various life processes.

• Aerobic respiration- This process of respiration occurs in the presence of oxygen and produces carbon dioxide, water & energy.

• Anaerobic respiration takes place in an oxygen-deficient environment, and yields energy yields fewer ATP molecules & as negative or byproducts — alcohol or lactic acid.

• Even plants breathe to metabolize their food and exhale energy, water &  carbon dioxide.

5. Movement and Locomotion

A common characteristic of living organisms is movement. It occurs in two forms:

• Locomotion – The movement of organisms from one place to another (e.g., birds flying, fish swimming).

• Towards the end, for internal or limited movement in the plant – You see the way in which the plant moves its organs leaves, roots or stems. A sunflower, for example, faces toward the sunlight.

6. Response to Stimuli (Responsiveness)

All living beings respond to environmental changes known as stimuli.

• Humans reflexively pull their hand away from a hot object; they salivate at the smell of food.

• Humans are scared when they notice possible risk.

• Even plants can be sensitive: the touch-me-not plant, also called Mimosa pudica, closes its leaves if touched; certain blossoms open & close at specif­ic times.

7. Excretion

Waste such as carbon dioxide, urea and other metabolic wastes must be expelled by organisms to maintain homeostasis.

• Humans and animals excrete long waste in the form of liquid waste (urine, sweat) & solid waste (stool). The lungs also remove carbon dioxide.

• Plants, by contrast, eliminate gaseous waste via stomata and eliminate unwanted substances by gums, resins, & loss of the dead bark.

8. Reproduction

The biological process of creating new offspring of the same kind as the parent.

• Viviparous animals (e.g., humans, dogs, lions) give birth to live young.

• Oviparous animals (e.g., birds, fish, insects) lay eggs.

• Plants reproduce through seeds or vegetative propagation (stems, roots, leaves, or cuttings).

9. Life Cycle

All living things have a life cycle: born, grow up, reproduce & die.

• The life expectancy is, predicated it the species differentiation. For instance, human beings have a lifespan of 60 to 80 years while for bacteria it is 20 minutes..

Lifespan of Different Organisms

 

Organisms and Their Surroundings

Things within the environment affect each other & rely on each other. The environment includes:

Biotic & Biotic relationship: The biotic components depend on one another for nutrition. Plants are also food for animals and other plants. When they die, and animals do their business, the waste products enrich the soil. The plants take in these nutrients for their growth.

Biotic - Abiotic Interactions: Biotic-abiotic interactions are always occurring. For example, all the creatures live due to the water and oxygen. Plants require sunlight, water, air, & soil as well.

Habitat and Adaptations

The term habitat refers to the location where an organism, or a population of organisms, lives in order to grow, survive, and reproduce. Animal behavior: Deer are not in a zoo, they are in the wild. A suitable place for organisms to live, in which they have food, shelter, and climate conditions to survive and grow, is a good habitat. When in a habitat that satisfies its needs, each species performs well with these adaptations. Every plant and animal has its own adaptations that help them survive their environment.

1. Terrestrial Organisms

Terrestrial organisms meaning the ones who live &  reproduce on land. On land; terrestrial habitats are further divided into:

a. Desert Habitat

Deserts have very low rainfall (<25 cm/year), but extreme temperatures. Desert organisms have-specialized adaptations for survival in extreme arid Halls of Kalahari & Sahara desert.

Adaptive Features:
Plants:

• Hence the deep root systems (like date palms) that have dug into underground sources.

• Plants that have fibrous roots and shallow roots (i.e. cactus) can soak up that water quickly after a downpour.

• Photosynthesis occurs in succulent, water-storing stems (i.e., cactus)

• Stems & leaves are coated with waxy coverings that keep moisture in.

• The leaves modified into spines to decrease the transpiration process.

Animals:

• Some burrow into the ground to cool off.

• Others go dormant (a stage known as “aestivation”) to ride out extreme heat.

• Camels, Known as the “ships of the desert,” have:

• They have long eyelashes that provide protection against sand.

• Long legs to lift their bodies off searing sand.

• Broad, cushioned paws for traversing sand.

• For one, by drinking up to 120 liters of water at a time.

b. Grassland Habitat

Grasslands are big open spaces with grass & a couple of trees. Dry conditions over moderate regions. There are some common animals also available here like deers, rabbits, zebra, lions, and elephants, etc.

Adaptive Features:
Plants:

• They have strong root systems for absorbing water.

• That is why leaves are thin so that they lose as little water as possible.

• Flexible stems so that strong winds can blow through.

Grazing Animals:

• Overgrown molars for pulverizing hay.

• The longer, stronger legs for escaping predators.

• Higher senses (olfactory, auditory) detect the threat.

Predators:

• Camouflaged skin will camouflage into the surroundings.

• Keen sight for night hunting.

• Powerful, retractable claws for stealthy movement.

c. Forest Habitat

The environment of forests, particularly tropical rainforests, is hot, humid, with rain occurring on most days. Dense vegetation prevents much light from reaching the forest floor. What you will find here are the animals & plants that thrive, monkeys, jaguars and snakes.

Adaptive Features:
Plants:

• Long leaves bear grooves with “drip tips” to allow excess rainwater to run off.

• Small plants reach out wide leaves to capture rare sunlight.

Animals:

• Other species (monkeys) have agents with muscular extremities for climbing.

• They have long arms for swinging through trees.

• Camouflage helps prey avoid predators, & predators stalk effectively.
  
  

d. Mountain and Polar Habitat

In the cold, windy, snowy mountains or polar regions. These regions host yaks, snow leopards & polar bears.

Adaptive Features:
Plants:

• Snow tumbles off the shelves of cone-shaped trees.

• The waxy needle them, so the little leaves, they have very little surface area, so you don't lose all of the water.

Animals:

• Polar bears, for example, have dense fur & blubber to insulate them.

• It’s also hooved itself — an adaptation that aids in rocky land traversal.

• The feathers of penguins, which are oily and water-repellent, keep them warm.

• Some animals spend winter in hibernation (a deep sleep) to conserve energy.
  
  

2. Aquatic Organisms

Hydrophytes are also called as aquatic organisms and they live & reproduce in water. Aquatic habitats can be broadly classified into two types:

1. Freshwater habitat – Includes rivers, lakes, & ponds (e.g., frogs, water lilies, lotus).

2. Marine (saltwater) habitat – Includes seas and oceans (e.g., whales, sharks, seaweed).

Adaptive Features:
Aquatic Plants:

• Floating plants(e.g. water hyacinth) have air spaces in their stem to prevent sinking.

• Submersed plants (Vallisneria, e.g.) that you want to avoid have flexible, mucilage coated leaves.

• Only the upper surface of floating leaves have stomata to facilitate gaseous exchange.

Aquatic Animals:

• Long aerodynamic bodies reduce drag as they swim through water.

• Fish used their gills to breathe underwater. Blowholes are found in both dolphins &  whales.

• Body covering (hard covering, scales, or waxy covering) to retain water.

3. Amphibians

Amphibians spend some time in land and some time in water. They rely on water to breed. Examples: frogs, toads & salamanders.

Adaptive Features:

• Webbed feet for swimming.

• The images are of gills or fins developed for gills.

• Lungs for breathing on land.

• Strong hind legs for jumping.
  
  

4. Aerial Organisms

They are always in flight; they are airborne organisms. This group includes birds, bats, and flying insects.

Adaptive Features:

• They can afford to develop more aerodynamically efficient bodies that lead to less air drag when flying.

• Wings are modified forelimbs.

• They also have hollow bones which make their bodies light.

• Strong flight muscles & great vision assist with survival.
  
  

5. Arboreal Organisms

Arboreal animals reside in trees — that is: they are tree-dwelling creatures. This includes monkeys, squirrels, and certain types of birds.

Adaptive Features:

• Big arms and legs for climbing

• Hooked claws for grabbing limbs.

• Some monkeys have prehensile tails, but those are for balance & support.

And each organism is adapted to its own environment. On land, in water, and in the air, and on trees, animals & plants have adapted to the condition within their environments. Studying these adaptations provides us with understanding of the diversity but also complexity of life on Earth.

 

Real-Life Examples

• A polar bear has thick fur and a layer of fat to survive in icy regions.
• Camels have long legs and thick eyelashes to survive in deserts.
• Fish have fins & gills to live underwater.
• Birds have hollow bones for easy flight.

Things you have learned!

1. Living organisms grow, move, reproduce, respond to stimuli, excrete, and need food, water, and air to survive.
2. A habitat is the natural home of an organism, providing food, water, shelter, and suitable conditions to live.
3. Organisms have adaptations—structural, behavioral, or physiological—that help them survive in their specific environments.
4. Based on their habitats, organisms can be terrestrial, aquatic, amphibians, aerial, or arboreal.
5. All living things perform life processes like nutrition, respiration, growth, excretion, reproduction, and responding to stimuli.