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 (ancient) life forms• ECOLOGY – study of life and surroundings

(environments)

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 energy4. All organisms maintain homeostasis5. All organisms respond to the environment6. 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

Red Blood Cell

Nerve Cell

Bacteria

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-

photosynthesizers use solar energy, (autotrophs)

chemosynthesizers use chemical energy, (autotrophs)

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

• Every living thing has DNA. That means that you have something in common with a zebra, a tree, a mushroom and a beetle!!!!

Classification

• 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

Classification

• 6 KINGDOMS• Animalia• Plantae• Fungi• Protista• Prokaryotes• Eukaryotes

• Viruses are not classified as living. Viruses do however demonstrate reproductive capabilities like living things. They are smaller than bacterial cells!

Used to be 1 kingdom- Monera (Bacteria only)}

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!

Puma ?

What is my name?

Devil Cat ?

What is my name?

Ghost Cat ? What is my name?

What is my name?My real name is Puma concolor

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?

    Two name system for writing scientific names.•The genus name is written first (always Capitalized).     •The 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

Binomial Nomenclature

• More examples-

Panthera leo Lion Africa (Asia)

Panthera onca Jaguar N. & S. America

Panthera pardus Leopard Africa, Asia, Europe

Panthera tigris Tiger Asia

Genus and species Common name Range

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 phylogenies – evolutionary histories – of an organism or group

Organization of LIFE

• CELL – BASIC UNIT OF LIFE

• TISSUE- MANY CELLS

• ORGANS- MANY TISSUES

• ORGAN SYSTEMS-GROUPED ORGANS

• ORGANISMS – CONTAINS ORGAN GROUPS

• SPECIES- GROUPS OF THE SAME ORGANISM