Characteristics of Living Characteristics of Living ThingsThings

By the end of this presentation I should be able to identify whether something is living or not based on the Seven Characteristics of Living Things.

1. All living things are composed of some of the same basic elements…

organized differently• Carbon

• Hydrogen

• Nitrogen

• Oxygen

PhotosynthesisPlants take in Carbon Dioxide, water, and light

Within the chloroplasts of the plant cells, these elements are re-arranged to form glucose and the by-product oxygen.

6CO2 + 6H2O + light C6H12O6 + 6O2

Spontaneous Generation• Theory that life could “spring up” from

non-living matter– Disproved by Francesco Redi in 1668 through

his meat/maggot experiment– http://www.youtube.com/watch?v=WzbHOY5fGqc

– http://www.youtube.com/watch?v=0OmWbRKW4K8

2. All living things are made of cells

• Cells are the basic building blocks of all living things.

• Cells come from other cells• Unicellular: single celled organisms (bacteria)• Multicellular: organisms made of many cells

(humans)

3. All living things have movement• Animals move to find food and shelter.

Movement can be the difference between life and death.

• Plants do not move, but they bend toward sunlight.

• All living things also have internal movement of substances too (food, water, waste, etc).

4. Living things can perform complex chemical activities, such as

building up or breaking down chemicals

• Metabolism: The sum total of all chemical reactions that occur in living things- produces energy and basic materials needed for life processes

• Ingestion: To take in food and nutrients• Digestion: Break down of food• Chemicals used during and formed through these

processes are used for growth and repair OR are stored for later.Ex.) saliva contains an enzyme called amylase which helps break down starches into sugar, beginning the process of digestion

Chemical activities continued…

• We get the energy we need by combining the foods you eat with the oxygen you breathe (respiration).

-The heart pumps blood non-stop through a vascular network 96,600 kilometers (60,000 miles) long, the equivalent to twice the Earth's circumference at the equator!

•Excretion: Getting rid waste materials

–Ex.) exhaling carbon dioxide, excreting nitrogenous waste products, which otherwise can be poisonous to the body.

All of these functions combined help organisms maintain homeostasis- a state of balance in their body, stable conditions

5. Living things grow and develop• Birth

• Growth- become more complex

Lifespan: how long an organism lives (from birth to death)

6. Living things respond to their environment

• Stimulus: signal to which an organism reacts (change in environment– Ex.)When the season

changes from winter to spring there is much more dust and pollen in the air.

• Response: some action, movement, or change in behavior due to stimulus

-Ex.) you sneeze to keep germs, pollen and dust from entering your body.

Response to stimuli continued….• When organisms

continually respond to their changing environment new adaptations and characteristics can evolve within the species.

• Ex.) The finches of Galapagos Islands started out as the same species. Over time natural selection created many new species based on which beak was most “fit” to get food in its environment.

In response to stimuli, organisms also must be able to obtain and use energy

7. Living things reproduce

• Sexual reproduction: Two partners required (male and female)

• Most are multicellular

• Asexual reproduction: Only one parent, meaning the organism has all it needs to reproduce on its own

• Bacteria and some plants

Reproduction continued…• In both types of reproduction, the offspring

receive a set of special chemical “blue prints” or plans that determine the characteristics of that living thing, which will again be passed on the next generation.

• These “blue prints” of these characteristics is also known as DNA