What is Biology?

• Biology = the study of lifeBio- = life

-logy = the study of

• Concepts, principles and theories that allow people to understand the natural world

• Biologist = person who studies life

• Essential Questions in Science

– What?– Why?– How?

What do Biologist Study?

– Interactions of life• Living things do not exist in isolation• Living things depend on other living

things as well as non-living things

– Interactions of the environment• No species can exist in isolation from

the environment around them– Ex. If you study rabbits, you would also

study the plants they eat and animals they prey on them

– Problems and propose solutions

What is an organism?

• An organism is anything that possesses all the characteristics of life

• Living things are organized– Living things have structure– All parts function together in an

orderly way

Characteristics of Life• Organization (Cells) - Living things have structure

– All parts function together in an orderly way

• Reproduction – making more organisms of the same kind

• Growth and Development – living things change during their life

• Adaptation/Regulation – responding to changes in the organisms surroundings

• Exchange Gases – Move gases in or out of body (ex. CO2, O2)

• Use Energy– Metabolism (release of energy from food)

• Excretion – eliminating waste materials produced by the organism

• Movement – all living things move (internal and external)

• How do we answer questions about life?– We use the Scientific Method

• Set of organized steps that help us answer questions about observations that we make

Steps of the Scientific Method

• Observation

• Research

• Hypothesis

• Procedures

• Experiment

• Organize Data

• Make Conclusion

• Share Results

Observation

• Use your 5(4) senses to notice things around you– See an organism change color– Hear an organism make a sound– Feel the texture on an organism– Smell an odor– Taste – Never taste anything in lab!!!

• Develop a question based on your observations

Research

• Find out as much as you can about what you observed– Look it up!

• Computer• Books• Journals• Talk to experts in the field• Newspaper• TV• Prior knowledge

Hypothesis

• Make an educated guess– I stress the word “educated”

• Your hypothesis is a guess, but it is a guess based on information that you have learned from your research

• I hypothesize that…..

Procedures

• Write the steps you will use to test your hypothesis– First I will ….– Then I will ….– After that, …..– Next, ….– Finally, ….

Experiment

• Test your hypothesis using the procedures you have written\– When you experiment

• Follow procedures closely• Follow safety rules• Make observations• Record data collected

Organize Data

• Try to make sense out of the data you collected and organize it in a way that tells a story– Make charts, graphs or tables– Look for “trends” in your data

Make a Conclusion

• Determine what your data is telling you.

• Does your data help to confirm or disprove your hypothesis?

• Does your data answer your initial question?

• What does it mean?

Share Your Results

• If you don’t share what you found how will anyone know?

• It is important for scientist to let others know what they have discovered.

• Scientist usually publish their research in scientific journals– When scientist publish their research they

use a specific format. All scientific journals use the same format

What are you doing Friday Night?

• Use the Scientific Method to go through the steps you would use to figure out what you will do this Friday night.– Observation – what is there to do???

– Research – find out!

– Hypothesis – what do you think will happen?

– Procedures – how will you go about it?

– Experiment – the actual activity

– Organize Data – What happened

– Make Conclusion – Ok, so how did it go?

– Share Results – You know you will tell all your friends about it…

Experimental Variables

• When you do an experiment you should always be aware of your variables

• There are three types– Independent Variables– Dependent Variables– Controlled Variables

Independent Variables

• The condition in the experiment that is changed– By changing the independent

variable, a scientist can observe or measure the effects of the change

Ex. Growing plants

You want to determine the effect of water on the growth of a plant, in that case, your independent variable would be water.

Dependent Variables

• Any change that results from the manipulation of the independent variable

Ex. Growing plants

When you change the amount of water that you give the plants (independent variable), the growth of the plant slows down. The dependent variable is the height of the plant or the number of flowers that the plant produces

Controlled Variables

• Also referred to as a “Constant”• The standard, the part of the

experiment in which all conditions are kept the same.

Ex. Growing plantsYou change the amount of water you give the plants (independent variable), but you keep everything else the same, like amount and type of soil, and fertilizer, amount of sunlight, temperature….

Replication in Experiments

• You can’t determine the effect of less water on a plant if you have only one plant.

• You must replicate

• More is always better!

What happens when many people come up with the same results?

• Theory– After a hypothesis has been tested

and the same results are obtained many times by many people, a hypothesis may become a theory.

• Law– After a theory has been tested and

the same results are obtained many, many, many times by many, many, many people, a theory may become a law.