Spontaneous Generation How did life start on our wonderful Earth? Spontaneous Generation

Early Earth Formation began approximately 4.6 billion years ago. Composition of the early Earth’s atmosphere: Water vapor Carbon Monoxide & Carbon Dioxide Hydrogen Sulfide Methane Hydrogen

Spontaneous Generation The theory that living organisms can come from non-living objects. IS NOT TRUE!!!

Spontaneous Generation Disproved by 2 scientists: Francesco Redi Conducted an experiment to disprove spontaneous generation in large visible organisms. Louis Pasteur Conducted an experiment to disprove spontaneous generation on the microscopic organisms.

How did life originate on Earth? We don’t know! What we do know: There is evidence for the creation of the building blocks of life in the harsh conditions of the Early Earth There are locations in the Earth where these building blocks would be protected from the harsh conditions of the Early Earth What sparked life from these building blocks?  No evidence.

Where did the building blocks of life come from? 2 Most common theories Stanley Miller (Miller-Urey Experiment) Simulated the conditions of the early Earth, which created the building blocks of life! Comets & Meteors Past studies have found the existence of peptides within Meteorites More evidence may come from the recent Rosetta spacecraft and Philae lander.

Protected locations where life could have begun Deep within the Earth’s crust. Deep within the ocean, at the thermal vents.

Evidence of the first living organisms Rocks 3.8 billion years old show evidence of carbon compounds that are created by cells Stromatolites Ancient cyanobacteria which created fossils 3.5 billions years old

First Cells Modern Cells 3.5 Billion Years Ago Did not require Oxygen Consumers Simple (unicellular) Current Most require Oxygen Consumers, Producers, and Decomposers Simple and Complex (multicellular, contains nucleus)

The Characteristics Common to All Living Organisms Life

Needs of Living Organisms Organization and Transport Growth and Development Reproduction Response to Stimuli Homeostasis Use of energy

Organization and Transport Organisms have specialized structures to perform specific functions Unicellular: Made up of one cell Are able to simply move substances into and out of the cell using diffusion Multicellular: Made up of many cells Same as unicellular, but also requires a circulatory system to bring substances to and away from each and every cell.

Growth & Development Increase in size or number of cells Multicellular organisms have cells develop to perform specialized functions. Some organisms go through Metamorphosis: A process in which an animals body undergoes dramatic changes in form

Reproduction Producing offspring of the same species. Internal Development When an offspring develops in their mother (Live birth, ex… humans) External Development When an offspring develops outside their parents body (Eggs laying organisms, ex… birds)

Reproduction Sexual Reproduction Asexual Reproduction 2 Parents 2 Types Sexual Reproduction Asexual Reproduction 2 Parents Offspring are not identical to parents 1 Parent Offspring are identical to parent

Asexual Reproduction Budding Binary Fission When an organism grows off the parent Example: Hydra When one cell splits in half into 2 cells. Example: Bacteria

Asexual Reproduction Budding Binary Fission

Response to Stimuli To survive organisms must be able to respond to stimuli. More complex (multicellular) organisms have a nervous system to respond to stimuli. Nervous System: Stimuli are converted to messages in the form of (electrical) impulses that are sent through neurons to the central nervous system. Neurons are used to send messages of stimuli and messages to muscles cells to respond

Response to Stimuli cont… Endocrine System: Uses hormones (chemicals) to transfer messages throughout the human body.

Homeostasis & Regulation A constant internal environment Examples: Warm blooded animals create their own heat to regulate their body temperature Cold blooded change their behavior to bask in the sun to regulate their body temperature

Use of Energy Respiration: Release of chemical energy Occurs in each and every cell of your body How do organisms obtain chemical energy?

Heterotrophs Autotrophs Chemotrophs Organisms that must obtain their source of energy by consuming (eating) other organisms are known as.. Heterotrophs Organisms that obtain energy of the sun and use it to create food are… Autotrophs Organisms that obtain energy from chemicals found in extreme environments are known as… Chemotrophs

The molecules that make of all living things The chemistry of living things The molecules that make of all living things

What are organisms made of? Carbohydrates Proteins Fats/Oils Nucleic Acids Water

Carbohydrates Made of C,H,O Main source of energy for living things Used to provide structural support The walls of plants are made of starch, a large carbohydrate.

Proteins Made of C,H,O,N are long changes of Amino Acids (the building blocks of a protein). Used as an energy source Used for structure: to build hair, muscles, and other body parts Used for cell communication Hormones are made of proteins and are used to communicate information to different body structures. Used to speed up chemical reactions Enzymes are proteins that help the body speed up reactions (such as breaking down food)

Lipids (Fats/Oils) Made of C,H,O Used as an energy source Used for long term energy storage Provides cushioning and insulation Used as a protective barrier Lipids do not mix with water, acting as a barrier to water soluble substances.

Nucleic Acids “Blueprints of life” Store the instructions for all processes within a living organism Example: Cell growth, reproduction, etc… Examples: DNA (deoxyribonucleic acid) RNA (Ribonucleic acid)

Water O H H Helps dissolve (break down) food Transports heat, food, and waste Helps maintain a constant body temperature Drink more water!! (and less sugary drinks) H O H