1. What is Life? Honors Biology Ms. Leyda 2012-2013 Honors Biology Ms. Leyda 2012-2013

2. 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  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

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

5.  Multicellular: organisms made of many cells.  This includes most organisms you are familiar with. The picture below shows the numerous cells composing a very thin section of an onion.  Multicellular: organisms made of many cells.  This includes most organisms you are familiar with. The picture below shows the numerous cells composing a very thin section of an onion. 1. Made of Units Called Cells

7. 2. Reproduction Organisms reproduce to perpetuate (continue) their species, and produce offspring that look like themselves. Definition

8. 2. Reproduction  Sexual Offspring come from a single parent - Offspring is identical to the parent Offspring of two parents. Creating by the joining of 1 cell from each parent. - Offspring is unique, different from either parent  Asexual 2 Types of Reproduction

9. 3. Based on a Genetic Code 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. DNA = Deoxyribonucleic acid DNA is a molecule that stores genetic information in organisms. Definition

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

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

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

14. 5. Obtain and use Materials and Energy  In every process, cells use energy.  In other words, constantly!!  In every process, cells use energy.  In other words, constantly!! How often do cells use energy?

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

16. 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.

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

18. 6. Respond to Stimuli 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. 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. Definition

19. 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.

20. 7. Maintain a Stable Internal Environment Living things maintain constant temperature, pH etc. inside their bodies.  Your body runs a tight ship. Conditions on the inside are tightly controlled. Living things maintain constant temperature, pH etc. inside their bodies.  Your body runs a tight ship. Conditions on the inside are tightly controlled. Definition

21.  Homeostasis: Regulation and maintenance of a constant internal condition inside an organism.  Homeostasis: Regulation and maintenance of a constant internal condition inside an organism. 7. Maintain a Stable Internal Environment

22.  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.  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. 7. Maintain a Stable Internal Environment

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

24.  Evolution: Process of biological change by which descendants come to differ from their ancestors.  Evolution: Process of biological change by which descendants come to differ from their ancestors. 8. Taken as a group, Change over time