Characteristics of Life and Cell Evolution

Biology

The study of life/living things

Organism

A living thing

Biotic

Anything that is alive

Abiotic

Things that were never living

First Characteristic of Life... Made of???

Made of Cells; complex & organized, cell = basic unit of life, prokaryotic and eukaryotic)

Prokaryotic

Type of cell without a nucleus

Eukaryotic

Type of cell with a nucleus

Second Characteristic of Life... Responds to???

Respond to Stimuli; reacting to internal and external changes (ex. phototropism, geotropism, thigmotropism, hydrotropism)

Third Characteristic of Life... Maintains???

Maintain Homeostasis; keeping stable internal conditions

Fourth Characteristic of Life... Aquires???

Acquire Energy; obtaining and using energy

Autotrophic

Organisms that make their own food

Heterotrophic

Organisms that get carbon and energy from food sources

Metabolism

The sum of all chemical reactions in a cell or organism

Cellular Respiration

Process where cells break down glucose to produce energy (C6H12O6 + 6O2 = 6CO2 + 6H2O + ATP)

Photosynthesis

Process where plants use sunlight to convert water and carbon dioxide into glucose (Sunlight + 6H2O + 6CO2 = C6H12O6 + 6O2)

Fifth Characteristic of Life... Grow and???

Grow and Develop; increasing in complexity

Sixth Characteristic of Life... Create offspring???

Reproduce; Being able to create offspring

Asexual Reproduction

One parent organism produces offspring

Sexual Reproduction

Genetic material from two parents combines to form offspring

Seventh Characteristic of Life... Contains???

Contain DNA; Having genetic material that carries instructions for life

Eight Characteristic of Life... Have the capaticy to???

Have the Capacity to Evolve; ability to change over time

Are viruses living or nonliving? Why or why not?

No because they aren't made of cells, have no source of energy, and cannot reproduce unless they use a host cell.

Hierarchy of Life

Simplest to Complex

Subatomic Particles

The particles that make up an atom. Ex. protons, neutrons and electrons.

Atom

An element. Ex. carbon, nitrogen, oxygen.

Molecule

Atoms bonded together. Ex. water, glucose, and DNA.

Organelle

A structure within a cell performs a specific function (like a small organ). Ex. mitochondria, nucleus.

Cell

Smallest unit of life. Ex. paramecium, nerve cell (neuron), muscle cell, blood cell, bacteria.

Tissue

A group of cells that perform a specific function. Ex. nervous tissue, muscle.

Organ

A structure usually composed of several tissues that form a functional unit. Ex. brain, liver and eye.

Organ System

Two or more organs working together in the execution of a specific bodily function. Ex. nervous system, digestive system.

Multicellular Organisms

A living thing composed of many cells, many organ systems working together. Ex. mushroom, tulip, octopus, tiger.

Population

Members of one species inhabiting the same area.

Definition of species?

Group of organisms that can interbreed and produce fertile offspring

Community

Two or more populations of different species living and interacting in the same area. All BIOTIC in an assigned area.

Ecosystem

A community together with its nonliving surroundings. Biotic AND abiotic.

Biome

Specific area of an ecosystem. Our biome, Deciduous Forest.

Biosphere

All of Earth's ecosystems combined, the areas that are inhabited by life. Ex. rainforest, tundra, desert.

Taxonomy

System used to classify organisms and assign scientific names

A good classification system has what?

Reveals evolutionary trends, shows relationships, and allows change of the taxon of an organism on new information.

Domain

Highest taxonomic rank; includes Bacteria, Archaea, Eukarya

Kingdom

Taxonomic rank below domain; includes Eubacteria, Archaebacteria, Protista, Fungi, Plantae, Animalia

Binomial Nomenclature

Scientific naming system with two words: Genus species

Human's Taxonomy?

Domain: Eukarya

Kingdom: Animalia

Phylum: Cordata

Class: Mamalia

Order: Primates

Family: Hominidae

Genus: Homo

Species: sapiens

Abiogenesis

Theory of how life on Earth arose from nonliving matter.

4.6 bya???

Earth formed

3.5 bya???

Oldest cell fossils (prokaryotic)

2 bya???

First eukaryotic cells

1.5 bya???

First multicellular organisms

0.5 bya???

Life moves to land

Inorganic

Simple molecules that do NOT contain carbon AND hydrogen at least. Early gasses: H2, H2O, NH3, CO2.

Organic

Complex molecules that do consist of carbon AND hydrogen at least. Ex. Glucose C6H12O6.

1st life?

Anaerobic Heterotrophic (prokaryotes that ate organic molecules)

2nd group?

Autotrophic prokaryotes (2.5 bya). First chemosynthesis then photosynthesis.

3rd group?

Prokaryotes that do aerobic cellular respiration.

Photosynthesis releases Oxygen!!! Allows for...

Development of aerobic cellular respiration

- much more efficient metabolism = more complex

organisms possible

2. Ozone layer formation (O3)

- protects organisms from

harmful sun radiation (UV)

3. Abiogenesis no

longer possible!!

- oxygen is too reactive to

allow abiotic to biotic evolution

Describe a Prokaryotic Cell...

-no nucleus and no membrane bound organelles
-some have a plasmid
-smaller than euk's and always unicellular
-cell wall is made of peptidoglycan (carbohydrate & protein)

Domain Bacteria, Kingdom Eubacteria

Some are disease causing, can be heterotrophic or autotrophic.

Domain Archaea, Kingdom Archaebacteria

Some are extremophiles. Ex. Thermophiles aquaticus lives in hot springs. Halophile (salt) lives in the Dead Sea. Gave rise to Eukarya.

Domain Eukarya

-Evolved from Domain Archaea (proks)

-All have eukaryotic cells "True Nucleus"

-Membrane-bound organelles (nucleus, ER, golgi...)

-Unicellular (yeast and many protists) and multicellular

Endosymbiotic Theory

Theory explaining how prokaryotes gave rise to eukaryotes through symbiotic relationships