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 system   organ  organism organ

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

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