Characteristics of Living Systems

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Transcript Characteristics of Living Systems

Characteristics of Living Systems

Living Systems

• Biology - The science of life and all living organisms, including their structure, function, growth, origin, evolution, and distribution. It includes botany and zoology and all their subdivisions. • BOTANY – study plants • ZOOLOGY – study animals • PALEONTOLOGY – study past • ECOLOGY – study of life and surroundings (environments) (ancient) life forms

Living Systems

1. All organisms are composed of one or more cells 2. All organisms are able to grow, reproduce and adapt 3. All organisms use energy 4. All organisms maintain homeostasis 5. All organisms respond to the environment 6. All organisms receive instructions from DNA

1. Cell Theory

• All living things are made up of cells. • Cells are the smallest working units of all living things. • All cells come from preexisting cells through cell division.

Definition of Cell

A cell is the smallest unit that is capable of performing life functions.

Examples of Cells

Amoeba Proteus Plant Stem Bacteria Red Blood Cell Nerve Cell

Two Types of Cells

•Prokaryotic •Eukaryotic (animal cells)

2. Adaptation • Any structure, behavior, process that promotes survival of a species.

– Cactus – have thorns – Camels – have humps of FAT on their backs – Camels foot – webbed to trek terrain

3. Organisms use energy

All Life needs energy-


(autotrophs) use solar energy,


(autotrophs) use chemical energy, Most other organisms use the energy stored as the bodies of the these two. (heterotrophs)

4. Homeostasis

• Steady state of being regardless of external surroundings.

• Maintaining a stable internal environment – Shiver when cold.

– Sweat when hot.

5. Environment- surroundings

• Biotic factors – all things alive or that once lived.

• Abiotic factors – all things that never lived but affect life.

6. Instructions from DNA


living thing has


. That means that you have something in common with a zebra, a tree, a mushroom and a beetle!!!!


• Taxonomy naming system for the organization of life.

– Grouping or categorizing based on similarities Modern classification began with the work of Carolus Linnaeus, who grouped species according to shared physical characteristics. In the life sciences,

binomial nomenclature

is the formal method of naming species. As the word "binomial" suggests, the scientific name of a species is formed by the combination of two terms: the genus name and the species descriptor.

Classification of living systems

• Kingdoms • Phylum • Class • Order • Family • Genus • Species


• 6 KINGDOMS • Animalia • Plantae • Fungi • Protista • Prokaryotes • Eukaryotes } Used to be 1 kingdom- Monera (Bacteria only) • Viruses are not classified as living. Viruses do however demonstrate reproductive capabilities like living things. They are smaller than bacterial cells!

The 6 kingdoms

• Prokaryotes (Used to be 1 kingdom, Monera) – Archaebacteria – Eubacteria • Eukaryotes – Fungi – Protista – Animal – Plantae

Overview of the 6 kingdoms

• Archaebacteria – Unicellular – Live in extreme environments – Prokaryotic • Eubacteria – Unicellular – Prokaryotic – “Common bacteria”

Overview of the 6 kingdoms

• Protista – Eukaryotic – Unicellular or colonial – Lots of different life styles • Fungi – Cell walls made of chitin – Eukaryotic – Multicellular – External heterotrophs

Overview of the 6 kingdoms

• Plantae – Eukaryotic & Multicellular – Cell walls made of cellulose – Autotrophic • Animalia – Eukaryotic & Multicellular – No cell walls – Internal heterotrophs

•Let’s look at an example!

What is my name?

Puma ?

Devil Cat ?

What is my name?

Ghost Cat ?

What is my name?

My real name is

Puma concolor

What is my name?

Binomial Nomenclature

• •

There are at least 50 common names

for Puma concolor .

Common names vary according to region, country or language.

Soooo……why use a scientific name?

Binomial Nomenclature Two name system for writing scientific names.


genus name is written first (always Capitalized).


species name is written second (never capitalized).

•Both words are italicized if typed or underlined if hand written. The name is also in Latin (a dead language).

Binomial Nomenclature

• More examples-

Genus and species Common name Range

Panthera leo

Lion Africa (Asia)

Panthera onca Panthera pardus Panthera tigris

Jaguar Leopard Tiger N. & S. America Africa, Asia, Europe Asia

How many organisms are out there?

• Scientists currently estimate that – There are 10 million species worldwide – Over 5 million live in the tropics – Most unnamed species are small or microscopic

Why is taxonomy useful?

• Helps prevent confusion among scientists • Helps to show how organisms are related • Can be used to reconstruct


– evolutionary histories – of an organism or group

Organization of LIFE