Themes of Biology Biology CPA Miss Colabelli

Biology  The study of life  Biologists study the smallest organisms, like bacteria, to large animals like elephants  Many different types of biology  Nutritional  Micro  Pathology

Characteristics of Life  All living things have similar qualities  Broken down into 7 characteristics of life  Organization  Response to stimulus  Homeostasis  Metabolism  Development  Reproduction  Evolution

Organization  Degree of order when an organism’s internal and external parts  Each living organism is made of one or more cells  Cell  tissue  organ  organ system  organism

Response to Stimuli  Living organisms have the ability to respond to a stimulus  Can be a physical change  In response to the environment  Necessary for an organism to survive in their environment and stay alive

Homeostasis  Organisms must maintain an internal balance  Due to environmental change  Regulatory system in order to keep balance  Body temperature  Salt intake and water intake

Metabolism  Organisms need to make energy from their environment  Humans eat food in order to get energy  Plants make their food from the sun and water

Growth and Development  All living things grow and increase in size  Done by division and making new cells  Cell division is when one cell is made from a pre-existing cell  Development is the process of an organism maturing into an adult

Reproduction  Process of living things producing themselves  Essential for continuing a species  Some organisms lay eggs, some have a baby grow internally  The process of two organism passing their DNA to its offspring is sexual reproduction  Two parents  one or more organisms  The process of one organism making an identical copy of itself is asexual reproduction  One parent  2 daughter cell

Evolution  Change over time  Populations of an organism can change based on environmental conditions  Important for survival in a changing world

Diversity & Unity of Life  All living things have features that are common

Tree of Life

 How scientists organize organisms into groups that are similar to each other  Scientists believe we descended from one common ancestor (the roots)

Tree of Life  The common ancestor branched out into diverse species  Organisms change due to their environment

Three Domains of Life

Interdependence  Organisms interacting with each other  Ecology is the study of organisms interacting with each other  When ecologists study organisms in a specific environment it is called an ecosystem

Ecosystem

Human Impact  Humans have been on earth for a very small amount of time  Our impact on the planet has been drastic  Think of some environmental changes humans have caused…

Evolution of Life  Organisms change over time BUT their genetic characteristics do not  Populations that change over time is known as evolution

Misconceptions

Evolution  Descent with modification when inherited traits within a population  Small changes over a long period of time that a new genetically distinct new species can arise  Tree of life is a symbol for this evolution over time

Natural Selection  Organisms that have favorable traits are better able to survive and pass on their traits to next generation

What do you see?

Black & Peppered Moths

Adaptation  Traits that improve an individuals ability to survive  White rabbit and short ears in snowy place  The individuals that survive are able to pass on traits to next generation

Analyzing Graphics  Would you think that Archaea are more closely related to Bacteria or Eukarya?

Review  Why is evolution important in helping explain the diversity of life?  What is the difference between evolution and natural selection?

Make a hypothesis  Fossil evidence shows that bats descended from shrewlike organisms that could not fly. Write a hypothesis for how natural selection might have led to flying bats.

Designing and Experiment  Scientific Method  Observation  Question  Form a hypothesis  Experiment  Data collection and analysis  Conclusion

Observation and Question  Begins with observing something in nature  2 types of observation  Qualitative – using senses  Quantitative – measurement  Wondering how or what about it  Ex:  Observation: Owls capture prey in the dark  Question: How do owls detect prey in the dark?

Hypothesis  Possible answers for question in mind that you can test with an experiment  Educated guess of how something occurs  Can be more than one  Ex:  Owls hunt in the dark by vision  Owls hunt in the dark by hearing  Owls hunt in the dark by sensing body heat

Experiment  Design an experiment to test your hypothesis  Controlled experiment  Control group  What you compare data to  Experimental group  What you are testing for  Independent variable  What is being tested for (ex: presence or absence of light)  Dependent variable  How the experiment responds (ex: if the owl can catch its prey)

Collecting/Analyzing Data  Collecting Data  Usually quantitative data  Compare experimental results to controlled results  Analyzing Data  Compare results to other studies and refine hypothesis  Create charts, graphs, tables to show data

Conclusion  Either supports or rejects your original hypothesis  If it supports  Can move on to construct a theory with research  If it rejects  Refine and change hypothesis and create new experiment