1 Study of Life

2 What is Biology? Biology is the study of all living things Living things are called organisms Living things are called organisms Organisms include bacteria, protists, fungi, plants and animals

3 All Living Things Share Common Characteristics 1. Have Cellular organization 2. Are made from Chemicals 3. Obtain & Use Energy 4. Grow & Develop 5. They Reproduce 6. Respond To Their Environment

4 Characteristics of Organisms

5 1. All Organisms have Cellular organization Cells are the smallest living unit of an organism

6 2. Made of chemicals

Chemicals Chemicals are anything made of matter The smallest unit of matter is the atom Atoms are the smallest unit to make up an element 7

8 Chemical Groups Carbohydrates (provide short-term energy) Lipids (provide long-term energy & insulation) Proteins (provide movement) Nucleic acids, esp. DNA (deoxyribonucleic acid) carries the genetic code for all organisms

9 3. Cells Require Food & Energy

10 Food Requirements Autotrophs can make their own food –Most use the sun Heterotrophs can NOT make their own food –They must consume other organisms All organisms use energy, called ATP

11 4. Organisms Grow & Develop

12 Growth & Development Organisms GROW by producing more cells and by cell enlargement Organisms DEVELOP as they mature into an adult organism

13 5. Reproduction – 2 types Sexual Reproduction Involves 2 parents Genetically different Asexual Reproduction Involves a single organism or cell Genetically identical

14 6. Organisms Respond to Stimuli Organisms respond to stimuli (temperature, water, food supplies, etc.) in order to survive & reproduce

15 4 Needs of Living Things 1. Water Most cells contain Most cells contain 2. Food For energy For energy 3. Living Space For protection & maintaining #4 For protection & maintaining #4 4. Stable Internal Conditions

16 Homeostasis Homeostasis: Keeping the internal environment of the cell or organism within the ranges required for life Stable internal conditions of pH, temperature, water balance, etc. How do we remain stable??

17 Levels of Organization AtomsMoleculesOrganelles Cells – life starts here TissuesOrgansSystemOrganism

18