Biology: The Study of Life

Diversity of Life All living organisms that inhabit planet Earth

What do Biologists do? Biologists study interactions of life. Living organisms depend on one another

What do Biologists do? Biologists study life and its interactions with the environment. Oxygen and sugar from plants used by animals Animals produce CO2 that is used by plants.

What do Biologists do? Biologists study problems and propose solutions. Example: Why did honey bee colonies decline?

How do we know if something is alive All living things: 1) Have an orderly structure. 2) Produce offspring. 3) Grow and develop 4) Adjust to changes in the environment.

Living Things are Organized All living things are organized into Cells. Cells can make up more complex structures, but all are highly organized.

Living Things Reproduce A species is a group of organisms that can interbreed and produce fertile offspring. For a species to survive they must leave offspring.

Living Things Change During Their Lives Growth is an increase in the amount of living material and the formation of new structures. Development is all the changes that take place during the life of the organism. Growth Devlopment

Living Things Adjust to Their Surroundings Organisms exist within an environment that includes: air, water, temperature, weather, other plants and animals. Anything in the internal (inside the body) or external environment that causes a reaction is a stimulus. The reaction to a stimulus is called a response.

Homeostasis Organisms must maintain a balanced internal environment in order to survive. If temperature or pH are out of normal range proteins unwind and cannot do their job. Blood sugar is regulated by hormones (insulin and glucogon)

All Living Organisms Use Energy Energy is the ability to cause change. Plants transform the sun’s energy into food energy. Animals, fungi, and other organisms eat food to get energy.

Living Things Adapt and Evolve An Adaptation is any structure, behavior, or internal process that enables an organism to survive and produce offspring in a changing environment. An organism is born with the adaptation, they do not change. They just match the environment better.

Adaptations

Evolution Organisms that are well-adapted to their environment will survive and produce offspring. The traits that allowed them to survive will be passed to their offspring. Over time that trait becomes dominant in the population. That is evolution - gradual change over time.

The Scientific Method Scientific Method is a set of steps used to investigate scientific questions. 1) Observation or problem 2) Make a hypothesis 3) Design an experiment 4) Collect Data 5) Form a Conclusion

A Hypothesis is Tested by an Experiment A hypothesis is an explanation for a question or a problem that can be formally tested. The experiment is a test of the hypothesis under controlled conditions. Experiments have two groups: the control group and the experimental group. The control group keeps all conditions constant and is used for comparison – to be able to tell if something changes. The experimental group will have one condition that is changed or being tested.

Variables in an Experiment Independent variable is the condition that is being tested; it is the only factor that affects the outcome of the experiment. Dependent variable depends on the changes made in the independent variable. What the experimenter changes is the independent, what happens is the dependent variable.

Experiment without controls Sometimes an experiment does not have a control. Experiments on animal behavior are often descriptions of what animals are doing.

Common Safety Symbols

Data Collecting Data may be quantitative data (numerical data) temperature, length, time, counts Data may be qualitative data (descriptive data that does have measurements). This is verbal data. Data can be represented on graphs.

Graphing Rules 5 Rules for a Good Graph Graph must have a title that describes the variables. Axes are labelled. Axes have appropriate units. Axes are divided into units with equal increments. Graph takes up the entire grid.

Types of Graphs Line graph - used to show continuous change. Bar graph - used to compare counted items. Pie graph - used to show percentages. Remember independent variable on “x” axis. dependent variable on “y” axis.

After Analyzing Data, Make a Conclusion If data supports hypothesis, it is repeated over and over again, then published so that other scientists can evaluate the experiment. A hypothesis that is supported by a large amount of scientific evidence is a theory. If the data does not support the hypothesis, then it is rejected and another hypothesis can be proposed.

Natural Laws Natural laws are undisputed and accepted to be true, while theories can be changed if new information becomes available. Law of Gravity Theory of Evolution

Metric Measurement The SI (International System of Measurement) is used in science. It is based on multiples of 10. A meter is the unit of length. 1 meter = 100 centimeters = 1000 millimeters Centi means 1/100 Milli means 1/1000 Liter is the metric unit of liquid volume. Gram is the metric unit of mass. Celcius degrees is used for temperature and time is measured in seconds.

Science and Society Some discoveries in science raise questions about what is right and wrong. For example, is it all right to clone humans or have designer babies. Deciding what is right and wrong is called Ethics. The application of science to improve human life is called technology.