1. Unit 1 The Science of Biology

2. 1–1 What Is Science? A process of inquiry: Goal of science:
Asking questions, the answers to which produce a body of knowledge
That knowledge is subject to change and revision.
Goal of science:
Investigate and understand the natural world,
Explain events in the natural world and to use those explanations to make useful predictions.

3. Science only deals with the natural world.
Biology is a field in science that focuses on the study of life.

4. Scientists…
Collect and organize information in a careful, orderly way.
Look for patterns and connections between events.
Propose explanations that can be tested by examining evidence.
Try to explain events logically and analytically.

6. 1-2 How Scientists Work
Common steps for scientists to gather information and answer questions are known as scientific methods.
Not every scientific investigation uses every method, nor do all investigations lead to scientific theory.

7. 1-2 How Scientists Work
While there are no fixed steps, generally the scientific method involves these steps:
Make observation/Ask a question
Form a hypothesis
Set up a controlled experiment
Record and analyze results
Draw a conclusion

8. 1-2 How Scientists Work
MAKE OBSERVATION / ASK A QUESTION: observe and gather information about events or processes.
Research stage (previous investigations)
Scientific discovery often takes place when a scientist observes something no one has noticed before.

9. Observation involves one or more of the senses (sight and hearing)

10. DATA Information gathered through observations
Do not differ whether collected by one person or another.
Data is collected during initial observations and the experiment.

11. Two types of data:
Quantitative data: Measure what we observe.
Gathered using instruments (rulers, scales, beakers, etc.)
Qualitative data: Describe what we observe.
Uses your senses.

13. Scientists use data to make inferences, a logical interpretation based on prior knowledge or experience.
Often change with new observations

14. Nazca lines (Peru)

15. FORM A HYPOTHESIS: A proposed scientific explanation for a set of observations.
If/Then Statement - predicts a relationship between cause and effect.
Scientific hypotheses must be able to be tested.
Must be able to measure what you do and the results

17. SET UP CONTROLLED EXPERIMENT:
An investigation that tests a hypothesis by the process of collecting information under controlled conditions.
A controlled experiment involves 2 groups:
Experimental Group
Control Group

19. Experimental group: test group that receives experimental treatment.
Only 1 Variable is tested at a time.
A variable is the factor of an experiment that can change. There are three types of variables:
Constants (controlled variables): same for both the control and variable group.
Independent (Manipulated) variable: variable that is deliberately changed.
Dependent (Responding ) variable: changes in response to the manipulated variable (what happened).

20. Control group: group that receives no experimental treatment, the standard against which results are compared.

22. RECORD AND ANALYZE RESULTS:
Keeping a written record of observations and data is very important!
Data from an investigation can be considered confirmed only if repeating the investigation several times yields similar results.

23. DRAWING A CONCLUSION: Use evidence to determine if hypothesis is one of the following:
True
False
Partially True
If False or Partially True, revisit hypothesis and try again!

24. REPORTING RESULTS:
Results are useful only if they are made available to other scientists for peer review.
Other scientists can try to verify the results by repeating the procedure.

25. It is not always possible to do an experiment to test a hypothesis.
Alternative investigations may utilize fieldwork or surveys or large groups of subjects, controlling as many variables as possible.
As evidence accumulates from scientific investigations, a particular hypothesis may become so well supported that scientists consider it a theory. A theory is a well-tested explanation that unifies a broad range of observations.
No theory is considered absolute truth. As new evidence is uncovered, a theory may be revised or replaced.

26. “We might ask if the small size of the female brain depends exclusively upon the small size of her body... But we must not forget that women are, on the average, a little less intelligent than men, a difference which we should not exaggerate but which is, nonetheless, real. We are therefore permitted to suppose that the relatively small size of the female brain depends in part upon her physical inferiority and in part upon her intellectual inferiority.” Paul Broca ( )
INFERENCE LATER PROVEN INNACURATE. DATA WAS SOLID, INTERPRETATION FLAWED.

27. Science is an ongoing process,
Closing Thoughts:
Science is an ongoing process,
Constantly being reevaluated, revised and updated because of new tools, techniques and discoveries.
Good scientists are skeptics, questioning existing ideas and new hypotheses.

28. 1 – 3  Studying Life
Biology – “ology” the study of, “bio” life. Biologist - someone who uses scientific methods to study living things.
Describing what makes something alive is not easy.
No single characteristic is enough to describe a living thing.
Some non-living things share one or more traits with living things.

29. Living things share the following characteristics:

30. 1. Living things are made up of units called cells.

31. All living things show orderly structure (“organization”)
All living things have cellular organization.
Cells:
a collection of living matter enclosed by a barrier (cell membrane) that separates the cell from its surroundings.
the lowest level of structure capable of performing all of the activities of life.
are complex and highly organized despite their small size.
Unicellular organisms: living things that consist of only a single cell.
Multicellular organisms: contain hundreds, thousands or even trillions of cells with a variety of shapes and sizes. Each type of cell is specialized to perform a different function.

32. 2. Living things reproduce.
Hydra budding

33. All organisms produce new organisms (offspring) through a process called reproduction.
Reproduction is essential for the continuation of an organism’s species.

34. There are 2 types of reproduction:
Sexual reproduction: Two cells from different parents unite to produce the first cell of the new organism.
Offspring differ from their parents in some ways.
Asexual reproduction: New organism has a single parent.
Offspring and parents have the same traits.

36. 3. Living things are based on a universal genetic code.

37. The directions (blue print) for inheritance are carried by a molecule called deoxyribonucleic acid (DNA).
Every organism, with a few minor variations, interprets the genetic code of DNA in the same way.

38. 4. Living things grow and develop.

39. Growth is an increase in the amount of living material and the formation of new structures.
Growth can occur by increasing the size of a single cell or increasing the number of cells.
Development is all of the changes that take place during the life of an organism.
The development of specialized cells from a single fertilized egg cell is called differentiation, because the cells produced look different and perform different functions.

40. 5. Living things obtain and use materials and energy.

41. Organisms take in energy and materials and transform it to grow, develop, reproduce, and stay alive.
The combination of chemical reactions through which an organism builds up or breaks down materials as it carries out life processes is called metabolism.
All organisms get the material they need from their surroundings, or environment. The way organisms obtain energy varies.
Plants, some bacteria and most algae obtain their energy directly from sunlight through photosynthesis; they convert materials using light energy into a form of stored energy (glucose molecules).
Other organisms rely on photosynthetic organisms for their energy by eating plants or indirectly by eating organisms that ate plants. Decomposers obtain energy from organisms that have died by breaking down the organisms.

42. 6. Living things respond to their environment.

43. Organisms live in a constant interface with their surroundings, or environment, which includes other living organisms (biotic factors) as well as non-living factors (abiotic factors) like air, water, temperature and weather.
Anything in an organism’s external or internal environment that causes to react is a stimulus. A reaction to a stimulus is a response.
External stimuli come from the environment outside an organism. For example, light or temperature.
Internal stimuli come from within an organism. For example, thirst or hunger.

44. 7. Living things maintain a stable internal environment.

45. Even though conditions in the external environment may vary widely, the internal conditions of most organisms stay fairly constant.
The process by which they do this is called homeostasis.
A breakdown in homeostasis can result in disease or even death.
Homeostasis often involves internal feedback mechanisms, which respond to internal stimuli.

46. Negative feedback mechanism: A thermostat

47. Animals are not the only organisms to use homeostasis.
Plants must regulate carbon dioxide intake and water loss.
Plants use stomata (singular: stoma) - microscopic holes in a plant leaf (usually on the underside) that allow gases to enter and leave and water vapor to leave as well.

48. 8. Taken as a group, living things change over time.

49. Although individual organisms experience many changes during their lives, the basic traits they inherited from their parents usually do not change.
a characteristic that enhances the survival or reproduction of organisms that bear it is called an adaptation.

51. There are usually some differences in the adaptations of individuals within any population of organisms.
As the environment changes, some individuals have adaptations that make them better suited to the new conditions and more likely to survive and reproduce. As a result, individuals with these adaptations become more numerous in the population.

52. Over time, the characteristics of a species will change so that all individuals have the adaptation.
This process of change over time is called evolution.
Life evolves as a result of the interaction between organisms and their environments.