Investigate and understand the natural world Explain events in the natural world Use those explanations to make useful predictions

Organized way of using evidence to learn about the natural world

Observation Process of gathering information about events or processes in a careful orderly way

DATA Quantitative: Data expressed in numbers Qualitative: Characteristics that can’t be counted Brown old short cold angry

There are 9 ducklings Quantitative

The cat appears angry Qualitative

Inference: Logical interpretation based on prior knowledge or experience The crater lake of Volcan Irazu, Coast Rica Water Testing

Scientific explanation for a set of observations

Prior Knowledge Logical Inference Informed creative imagination

Testable Controlled experiment Gathering Data

What does it mean to describe a scientist as a skeptical? Question both existing and new ideas Science is ALWAYS changing

Steps in designing an experiment

? ? ? ? ? ? ? Ask a question Form a hypothesis Set up a controlled experiment Record and analyze results Draw a conclusion

Spontaneous Generation The idea life could arise from non-living matter

Experiment in which only one variable is changed at a time. All other variables should be kept unchanged or controlled Controlled Experiment Manipulated variable: Variable that is deliberately changed. Responding variable: Variable that is observed and changes in response to the manipulated variable.

Controlled Experiment Experiment in which only one variable is changed at a time. All other variables should be kept unchanged or controlled Sun Water Food Manipulated variable: Variable that is deliberately changed. Responding variable: Variable that is observed and changes in response to the manipulated variable.

Controlled Experiment Experiment in which only one variable is changed at a time. All other variables should be kept unchanged or controlled Sun Water Food Sun

Controlled Experiment Experiment in which only one variable is changed at a time. All other variables should be kept unchanged or controlled Water Food Sun Manipulated variable Responding variable

Controlled Experiment Experiment in which only one variable is changed at a time. All other variables should be kept unchanged or controlled Sun Water Food Water

Controlled Experiment Experiment in which only one variable is changed at a time. All other variables should be kept unchanged or controlled Water Food Sun Responding variable Water Manipulated variable

Controlled Experiment Experiment in which only one variable is changed at a time. All other variables should be kept unchanged or controlled Sun Water Food Sun Food

Controlled Experiment Experiment in which only one variable is changed at a time. All other variables should be kept unchanged or controlled Water Food Sun Food

Controlled Experiment Experiment in which only one variable is changed at a time. All other variables should be kept unchanged or controlled Water Food Sun Food Manipulated variable Experiment in which only one variable is changed at a time. All other variables should be kept unchanged or controlled

Controlled Experiment Experiment in which only one variable is changed at a time. All other variables should be kept unchanged or controlled Sun Water Food Manipulated variable: Variable that is deliberately changed. Responding variable: Variable that is observed and changes in response to the manipulated variable.

Why do scientists publish their results? So the experiment can be repeated Why do scientists publish their results? So the experiment can be repeated Why do scientists publish their results? So the experiment can be repeated Why do scientists publish their results? So the experiment can be repeated

Why are controlled experiments sometimes impossible? Ethics prevents experiments on humans In the field, researchers try not to disturb animals they observe

Theory Well tested explanation that unifies a broad range of observation Theory of relativity E=mc 2

vs. Hypothesis Theory Well tested explanation Proposed explanation

Characteristics of living things Make up of units called cells Reproduce Genetic code Grow and develop Obtain and use materials and energy Respond to environment Stable internal environment As a group, change over time

Cell Collection of living matter enclosed by a barrier that separates the cell from it’s surrounding

unicellular : contains only one cell

Multicellular: contains many cells

Reproduction Sexual reproduction: Two different parents unite to produce the first cell of the new organism Asexual reproduction: New organism has one parent. Divides in half or by budding.

Sexual or Asexual Reproduction? BOTH

DNA: Deoxyribosenucleic Acid: directions for inheritance

Obtain and use materials and energy: Metabolism: Chemical reactions through which on organism builds up or breaks down materials as it carries out its life processes Energy

Respond to environment Ducks flying south for the winter Alligators slow down eating Bears sleep in the winter months Artic fox’s coat changes color

Stimulus: Signal to which an organism responds. InternalExternal Low blood sugar=eat Seed responding to water, sunlight, and nutrients = growth

Homeostasis Maintain a relatively stable internal environment 98.6

Homeostasis Maintain a relatively stable internal environment 98.6

Homeostasis Maintain a relatively stable internal environment 98.6 SWEAT to maintain Homeostasis

Homeostasis Maintain a relatively stable internal environment 98.6

Homeostasis Maintain a relatively stable internal environment 98.6 shiver to maintain Homeostasis

Evolution The ability of a group of organisms to change over time Peppered moth

paleobotany

Herpetology

ethology

Entomology

Levels of organization Molecule Group of atoms, smallest unit of most chemical compounds Water molecule

Levels of organization Molecule Cells Smallest functional unit of life Liver cells

Levels of organization Molecule Cells Group of cells Tissues, organs and organ systems

Levels of organization Molecule Cells Group of cells Organism Individual living thing

Levels of organization Molecule Cells Group of cells Organism Population Group of individuals of one type that live in the same area

Levels of organization Molecule Cells Group of cells Organism Population Community Populations that live together in a defined area

Levels of organization Molecule Cells Group of cells Organism Population Community Ecosystem Community and nonliving surrounding

Levels of organization Molecule Cells Group of cells Organism Population Community Ecosystem Biosphere “Earth”

Levels of organization Molecule Cells Group of cells Organism Population Community Ecosystem Biosphere “Earth”

Levels of organization MCGOPCEBMCGOPCEB ost ows raze n umpernickle upcakes very irthday

Metric System: Decimal system of measurement whose units are based on multiples of 10

Microscope Produces magnified images of structures that are too small to see with the unaided eye.

Compound light microscope Focus visible light rays

Electron Microscope Magnifies images by focusing beams of electrons

How do scientists study cells? Cell culture: Group of cells grown in a nutrient solution from a single original cell.

How do scientists study cells? Cell fractionation: Cells are broken into pieces and the different cell parts are separated

How do scientists study cells? Cell fractionation: Cells are broken into pieces and the different cell parts are separated

How do scientists study cells? Cell fractionation: Cells are broken into pieces and the different cell parts are separated

How do scientists study cells? Cell fractionation: Cells are broken into pieces and the different cell parts are separated

How do scientists study cells? Cell fractionation: Cells are broken into pieces and the different cell parts are separated

Biology: Science that seeks to understand the living world