What Is Biology? The study of living things. Biologists Study? Characteristics Classifications Interactions between organisms Health & Disease
Goal of Science To investigate To understand To explain To make predictions ABOUT the World!
Levels of Organization (Place in Order from Smallest to Largest) Tissues Organs Molecules Cells Atoms Organ Systems
Levels Of Organization Atom Molecule Cells Tissues Organs Organ Systems
Levels of biological organization Largest Smallest
Defining What It Means To Be Alive
Characteristics of Living Things 1. Made Up of Cells 2. Reproduction 3. Based on a Genetic Code 4. Growth and Development 5. Need for Materials and Energy 6. Response to the Environment 7. Maintaining Internal Balance 8. Adapt & Evolve
1. Living Things are made up of Cells. Cells are basic unit of life CELL: Collection of living material enclosed within a barrier Unicellular: one cell Multicellular: many cells
Unicellular Multicellular
2. Living Things Reproduce: Asexual produce offspring which resemble parents 2 Types: Asexual reproduction: only 1 parent Sexual reproduction: 2 parents Sexual
3. Living Things are based on a Genetic Code/Organization Inheritance of traits is carried on DNA
From Dog To DNA 1. A dog is made up of more than a million cells. A Cell 2. Each cell contains a nucleus containing chromosomes. 4. A Chromosome 3. The cell s Nucleus 5. DNA molecule folds to form a chromosome 6. DNA is made of 2 strands.
4. Living things Grow and Develop GROWTH: increase in size & shape DEVELOPMENT: mature over time Living things have a Lifespan Growth Growth Development
5. Living Things Use & Need Energy Energy comes from food, used to maintain body AUTOTROPH: produce own food HETEROTROPH: must consume food DECOMPOSER: breaks down dead material for food
6. Living things respond to their surroundings React to a stimulus signal or change causing an organism to respond. a - The change could be internal or external. A response is a reaction caused by an action.
Stimulus? Response?
7. Living things maintain a Stable Internal Environment HOMEOSTASIS or DYNAMIC EQUILIBRIUM Examples: sweating, panting, shivering, etc.
Homeostasis How Does Your Body Bring You Back To Normal? & Why? To stay cool & prevent Perspiration overheating Shivering Regurgitation To stay warm Get rid of harmful wastes
Homeostasis If you think about it, your body works the same way. Most people maintain a constant body temperature around 98.6 degrees. That is your homeostasis. When facing conditions such as heavy exercise or hot weather, your body has numerous mechanisms to keep your temperature at homeostasis. Sweat is produced from glands in the dermis. 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. Living things Adapt & Evolve Adapt to changes in the environment Change to better survive in environment Changes take place over a long period of time & involve the entire species.
Adaptation A Cactus with horns A Camel s Hump To reduce water loss & protect from herbivores To store fat & live off it when food & water are scarce A Camel s webbed feet, long eye lashes, Prevent sinking in the & nostrils that close sand & prevent sand from entering eyes, nose
Life Processes: Terms 1. Nutrition taking materials & changing to a usable form (used for energy, growth, repair and maintenance) Digestion large insoluble molecules changed into small soluble molecule by enzymes. Ingestion to consume (take in) a substance Nutrient- a substance taken in for energy 2 Types Autotrophs make their own food Heterotrophs get their food
Photosynthesis for Energy Equation: Sunlight CO2 + H2O Sugar + Oxygen Light energy Chemical energy
Photosynthesis
2. Transport Substances enter and leave cells (movement of stuff within organism) A system in larger multicellular organism Example: Circulatory System (arteries/veins)
Transport of Materials Outside Cell Inside Cell
3. Cellular Respiration for Energy Cells burn food (glucose) for fuel (chemical energy) Energy is stored in molecules called ATP All cells continuously undergo this process called cellular respiration in the MITOCHONDRIA
2 Types Aerobic Respiration organisms use O2 to break food to make carbon dioxide & water. Anaerobic Respiration No O2 used to break down food.
Cellular Respiration ENERGY STORED Equation: Sugar + oxygen ENERGY RELEASED CO2 + H2O + Energy
4. Synthesis Simple substances combined (build) to form more complex substances (Needed for growth and repair)
5. Growth - More cells & bigger cells - Humans start as 1 cell & grow and develop into an organism of about 50 trillion cells. Examples: Unicellular- increase cell size Multicellular- go through growth called development
6. Excretion Removal of wastes from the body 4 Types of excretion: urination defecation exhaling sweating
7. Regulation All the activities that help maintain homeostasis Regulation occurs by nerve impulses (nervous system) & the release of chemical hormones (endocrine system) Needed to respond to the internal & external environment
8. Reproduction Produce new organisms of their own kind Two types: Asexual 1 parent with identical offspring Sexual 2 parents with offspring not identical
9. Digestion - Breakdown of COMPLEX food materials into simpler forms for organism to use.
10. Metabolism All the Chemical Reactions that occur in every cell to maintain normal functioning. The building & breaking down of complex substances. The continuous release of energy.
Virus
Virus Uses A Host s Cell For Reproduction
Is A Virus Living? Viruses have.. No Growth No Metabolism No Reproduction (uses a host for reproduction) What Do You Think Now?
Resource http://www.youtube.com/watch?v=_cpbk2t0 Yeo Life in a drop of water Youtube