What is Life? Biology

Vocabulary Cell Photosynthesis Respiration Metabolism Reproduction Unicellular Multicellular Reproduction Asexual Sexual DNA Nutrients Photosynthesis Respiration Metabolism Decomposer Stimulus/response Homeostasis Evolution

Characteristics of living things All organisms (living things) have/do: Made of Units called CELLS Reproduce Based on a Universal Genetic Code Grow and Develop Obtain and Use Materials & Energy Respond to stimulus (Environment) Maintain Homeostasis Taken as a group- Change over time

1. Made of Units (Cells) Definition All organisms are made of cells, which are like microscopic building blocks. • Cells: The basic unit of life • Unicellular: organisms made of only one cell They cannot be seen without a microscope.  Ie. Many pathogens (disease causing agents)

Unicelluar

1. Made of Units (Cells) Multicellular: organisms made of many cells. Includes most organisms you are familiar with.

Multicellular

2. Reproduction - To perpetuate (continue) a species Definition - To perpetuate (continue) a species - To produce offspring that look like themselves.

2. Reproduction 2 Types of Reproduction Sexual Asexual -Offspring of two parents. 1 cell from each parent joins together to create new life. - Offspring is unique, different from either parent Asexual - Offspring come from a single parent - Offspring is identical to the parent

3. Based on a Genetic Code DNA = Deoxyribonucleic acid Definition The genetic code of all living things on Earth is carried by DNA or RNA DNA = Deoxyribonucleic acid DNA is a molecule that stores genetic information in organisms.

4. Grow and Develop Definition Organisms will increase in size (grow) AND change in form (develop) during their lifetime. GROW DEVELOP

4. Grow and Develop What is a Life Cycle? The continuous sequence of changes from a single cell, to fully grown, then repeated with each generation.

5. Obtain and use Materials and Energy Definition Living things must get nutrients and energy from their environment. Some Examples: Macromolecules Carbohydrates (energy source) Proteins (cell building materials) Lipids (fats) (cell building materials) Nucleic acids (genetic materials)

5. Obtain and use Materials and Energy How often do cells use energy? CONSTANTLY! In every process, cells use energy. Respiration Photosynthesis Cell growth Reproduction

5. Obtain and use Materials and Energy Metabolism: All chemical processes than synthesize (make) or break down materials within an organism

5. Obtain and use Materials and Energy Photosynthesis: Process in which light energy is converted into chemical energy. Carbon Dioxide and Water produce Sugar and Oxygen.

5. Obtain and use Materials and Energy Decomposer: Organism that breaks down organic compounds into simpler compounds.

6. Respond to Stimuli Definition Living things must respond to changes in their environment. Anything in the environment that causes an organism to react is called a stimulus.  The reaction that takes place as a result of the stimulus is called the response.  Responses can be short-term or long-term and they can be positive or negative.

6. Respond to Stimuli Positive Response: causes the organism to move towards the stimulus.  Negative Response: causes the organism to move away from the stimulus. 

7. Maintain Homeostasis Definition Living things maintain constant, stable internal environment (ie. Temperature & pH) inside their bodies. Your body runs a tight ship.  Conditions on the inside are tightly controlled.

7. Maintain Homeostasis Homeostasis: Regulation and maintenance of a constant internal condition inside an organism.  

7. Maintain Homeostasis Most people maintain a constant body temperature around 98.6°F.  That is your homeostasis. When facing conditions such as heavy exercise or hot weather, you sweat.  As the water in the sweat changes from liquid to gas (evaporation), heat is lost allowing you to feel cooler.  Your face gets red and flushed.  This is due to the dilation of blood vessels which brings heat to the surface of your skin where it is lost to the environment. 

8. As a group, they Change over time Definition Living things on Earth today are different than living things on Earth thousands of years ago.  

8. As a group, they Change over time Evolution: Process of biological change by which descendants come to differ from their ancestors over time.