Themes of Biology

1. Themes of Biology Biology CPA Miss Colabelli

2. 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

3. 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

4. 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

5. 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

6. 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

7. 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

8. 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

9. 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

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

11. Diversity & Unity of Life • All living things have features that are common

12. Tree of Life

13. 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)

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

15. Three Domains of Life

16. 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

17. Ecosystem

18. 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…

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

20. Misconceptions

21. 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

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

23. What do you see?

24. Black & Peppered Moths

25. 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

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

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

28. 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.

29. Designing and Experiment • Scientific Method • Observation • Question • Form a hypothesis • Experiment • Data collection and analysis • Conclusion

30. 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?

31. 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

32. 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)

33. 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

34. 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