Biology: the Study of Life

What is Biology?

• What exactly does a biologist do?• What are the features of different organisms?• How do these features work?• Why do organisms have these features?• Are they similar to the features of other living things?• How do organisms interact with other organisms?• How do organisms interact with their environment?• How can we solve problems which endanger living

things?

• Do you think biologists have identified all the forms of life on Earth?

What is life?

• Characteristics of all living things:– Orderly structure (organization)– Produce offspring (reproduce)– Grow and develop– Adjust to changes in the environment

What is an orderly structure?

• All organisms are made up of one or more cells.

• Parts of organisms function together in a living system.

• Does an organism have to reproduce in order to be alive?

• Does a species of organisms need to reproduce in order to continue its existence?– Yes, if individual organisms within a species

don’t reproduce, the species will die out.

What is the difference between growth and development?

• Growth:– An increase in living material and formation of

new structures

• Development:– All of the changes (including growth) that

happen during an organism’s life

What is an organism’s environment?

• Its surroundings, where it is and what is around it.

• An organism also has an internal environment which it responds to as well.

Can an organism’s environment change? How?

• An environmental change which causes an organism to change is called a stimulus.

• What would we call the reaction to a stimulus? Response

• What are some examples of stimuli and responses?

• Some environmental changes cause a species of organisms to change permanently.

• This type of change is called adaptation.

What is homeostasis?

• Regulation of an organism’s internal environment to maintain conditions suitable for survival.– Occurs in all living things

• Adjustments are made unconsciously by our bodies - automatically

• Think of homeostasis as the way organisms keep their environmental conditions steady.

homeo stasis

same remaining constant

Example of homeostasis in humans:

• How do we keep our body temperature within the range needed for us to stay healthy?

• Normal temp. range: ~97 – 100, 98.6o F

• To raise temp.: shiver

• To lower temp.: sweat

Example of homeostasis in all living things:

• All organisms make constant adjustments to the amount of water and minerals in their cells.

What words do we use to describe the ways organisms change?

• Adjustment, response- temporary change

• Adaptation- in biology, refers to more permanent change, which is inherited from previous generations

• Evolution- accumulation of adaptations over many generations.

Scientists gather information

• Quantitative information– Measurement, numerical data– Count, graph, table

• Qualitative information– Non-numerical description– Pure observation