1. Chapter 1
The Science of Biology

2. What were your first questions?
WHY?
What?
How?

3. What is Science?
Science asks the same questions you did as a young child.
What is that?
Why does it do what it does?
How does that happen?
What happens if …?
Science (knowledge) is a process that investigates and attempts to understand and explain events in nature.

4. Goal of Science
Provide natural explanations for events in the natural world.
Give examples of this
Use explanations to understand patterns in nature and to make useful predictions about natural events

5. Since Science is a process, how do we go about doing “Science”?
The Scientific Method of course!!
Ask a question based on an observation
Do some research or infer
Propose a hypothesis
Conduct a controlled experiment
Collect data and make observations
Analyze data
Draw a conclusion

6. Observing and Asking Questions
Scientific investigations begin with observation, the act of noticing and describing events or processes in a careful, orderly way.
Researchers observed that marsh grass grows taller in some places than others.
A question is formed: Why do marsh grasses grow to different heights in different places?

7. Inferring & Forming a Hypothesis
Through observations and research, scientists form inferences, or logical interpretations based on what is already known.
These lead to a hypothesis, or a scientific explanation for a set of observations that can be tested in ways that support or reject it.

8. What kind of hypothesis could be made concerning the marsh grass growth?
Researchers inferred that something limits grass growth in some places. Based on their knowledge of salt marshes, they hypothesized that marsh grass growth is limited by available nitrogen.

9. Design a Controlled Experiment
Design an experiment that keeps track of various factors that can change, or variables
Only one variable is changed at a time
Manipulative or Independent variable
The variable that is observed and that changes in response to the independent variable is called the dependent variable (also called the responding variable).
All other variables should be kept unchanged, or controlled
Controlled variable

10. For the marsh grass experiment, identify each of the following variables:
Manipulative or independent variable
Nitrogen fertilizer is added to the soil
Control variables
Similar plant density, soil, plant type, sunlight, amount of water, temperature…
Dependent or responding variable
The rate at which the grass grows or its height.

11. Control and Experimental Groups
An experiment typically has two groups:
An experimental group contains the independent variable
A control group is exposed to the same conditions as the experimental group except for one independent variable.

12. Collecting Data Quantitative data Qualitative
How will scientists keep track of experimental observations and then analyze the results?
Collecting Data
Quantitative data
Numbers
How many blades of grass were found per meter?
How high, wide, long…was the grass?
How much nitrogen was found in the blades of grass?
Qualitative
Describe
Which way did the grass grow?
What color was the grass?
Where there any other plants growing around it?

13. Recording the data How is data recorded?
Use charts, photos, drawings or graphs
This graph shows how grass height changed over time.

14. What might have been a source of error in this experiment?
The larger the sample size, the more reliably researchers can analyze variation and evaluate differences between experimental and control groups.

15. What conclusion could be drawn from the data collected?
Use experimental data as evidence to support, refute, or revise the hypothesis being tested, and to draw a valid conclusion.
Marsh grasses grew taller than controls by adding nitrogen.

16. What if our hypothesis is not supported in our experiment?
Close but no cigar.
Reevaluated and revised the original hypothesis
Make new predictions
Redesign the experiment

17. Do you know where bees come from?
Recipe for Bees
Kill a bull during the first thaw of winter
Build a shed
Place the dead bull on branches and herbs inside the shed
Wait for summer. The decaying body of the bull produces bees
Words from a Roman poet about 2000 years ago

18. Spontaneous Generation
Life arises from non-living matter or just suddenly appear.
Abiogenisis
Meat grows maggots Corn produces rats Bread breeds mold
So what do you think of this theory?

19. How are new living organisms produced?
Question is stated Where do flies come from?
Now we need to form a hypothesis
Francesco Redi (1668)
Hypothesis: Flies lay small eggs on meat that become maggots
Set up a controlled experiment to test his hypothesis
Analysis: Found that by keeping flies away from meat, no maggots appear
Conclusion: Maggots are the result of flies laying tiny eggs on meat that develop into maggots

20. Variables Controlled variable: Jar, meat, location, temperature, time
Independent or Manipulative variable:
Gauze covering the meat jars
Dependant (responding) variable:
Whether maggots appear

21. Lazzaro Spallanzani 1776
Designed experiment to show that life did not arise spontaneously from food
Inferred that food spoils due to microbes in the food.
Took 2 flasks with broth in them
Boils on but leaves it open
Boils the other but has it closed
Results – Only the closed one
prevented growth

22. What was wrong with what Spallanzani assumed?
No air
Everyone knows that every living thing needs air to live
Whose experiment solved Spallanzi’s air problem?

23. Louis Pasteur - 1859 Tested Spallanzani’s work by using a
curved neck flask to prevent microbes from entering flask but would let air in
Boiled broth in control and experimental flasks.
Result: No growth in curved neck flask.
Microbes collecting in bend

24. Pasteur’s broth in the curved necked flask stayed sterile for years until he tilted it and the airflow carried the microbes into the broth

25. Conclusion
Contamination is due to microbes in the air.
Spontaneous generation theory died here!!
Biogenesis is born!!
All living things come from other living things.

26. Identify some scientific theories you have knowledge of.
Big Bang
Evolution
Relativity
A theory is a well-tested explanation for a range of phenomena.
A law is a concise, specific description of how some aspect of the natural world is expected to behave in a certain situation such as the Gas laws

27. What is Biology?
Biology is the study of living things and how they interact with each other.

28. What are the characteristics of living things?
You and your partner are to brainstorm and ask yourselves the following.
All living things have…
All living things need…
All living things can…
All living things must…
What makes a living thing different from the desk you are sitting in?

29. After you have brainstormed and edited your list, write them down on the chart on the next slide.
When told to do so, go to each station in the back of the room, observe the specimen and check off if it has the characteristics you wrote down.

30. Specimen
Trait 1 2 3 4 5 6 7 8 9 10

31. What makes something living?
Characteristics of Life
All living things…
…are made up of cells.
Unicellular or Multicellular.

32. 2…need a constant flow of energy.
Necessary for Metabolism
All the chemical processes taking place in the organism including those that are needed for growth and those that are needed to break down molecules (such as digestion)
Some such as plants and some bacteria, make their own food from raw materials (Autotrophic)
Others such as animals, need to process organic matter to obtain energy. (Heterotrophic)

33. 3… maintain a stable, internal environment by responding to stimuli.
Maintain an internal steady state – Homeostasis.
Stimulus – anything that causes an organism to react/respond
Examples:
Increased heart rate when stressed
Goosebumps and shivering.
Pupillary response to light and darkness
Let’s give this one a try

34. 4. …Evolve …as a group Evolution is a change in a species over time
Results from an species ability to adapt to changing conditions and reproduce.

35. Your very first baby picture
5…grow and develop.
Your very first baby picture
Process occurs by adding on more cells by cell division (making more cells of the same kind)
and cell differentiation (cells becoming different to suit their various functions).
Red blood cell White blood cell Nerve cells
Easily flow through Change shape to Like a wire to
capillaries squeeze through conduct electrical
intracellular spaces impulses

36. 6...can reproduce.
Adding on more cells or reproducing another organism
Passing on of genetic information (DNA and genes)
Not a necessary life process but needed for the continuation of the species.
Sexual (involves the fusion of two cells)
Asexual (involves only 1 cell dividing) reproduction.

37. 7. …all living things are based on a universal genetic code
DNA
It doesn’t matter if the DNA of a bacterium or a human is analyzed, we all have the same 4 bases (ATCG) making up our DNA.

38. Measurements in Science
SI Measurements (Standard Increments) aka: The Metric System
Unit Abbreviation
Length Meters m
Mass Gram g
Volume Liter l
Time Second s
Temperature Celsius `C
Kelvin `K
Density Mass/Volume g/l or g/cm3

39. Symbols of measurement
Prefixes Abbrevation Factor of base unit
kilo k ,000
deci d or 1/10
centi c or 1/100
milli m or 1/1000
micro u or 1/1,000,000

40. Metric Conversions Convert: 5L = ______ml 1.025cm = _______ m
Kilo Hecto Deka Meter Deci Centi Milli Micro
Liter
Gram
Convert:
5L = ______ml cm = _______ m
.035um = ______ mm 2.5mm = ______um
7.2g = _____kg .017g = ______mg

41. A recipe calls for 300ml of water. You add 0. 25 L
A recipe calls for 300ml of water. You add 0.25 L. Have you put in too much, too little or the right amount?
You are told that you need a jar with a volume of at least 150cm3. The label on the jar you find says 0.16L. Can you use it? Remember that 1cm3 = 1ml.

42. Lab Safety Contracts must be signed and returned to me immediately.
All Science students must complete the Safety contract before entering into the lab
Any student who does not have a lab safety contract signed will not be allowed to conduct labs.

43. The right tool is what is important Where babies really come from
Our method
The Way we do things here
Measure this
Watch it or the Safety Police will get you
They're a What?
Life is a Wonderful Thing
Used to measure out a volume of a liquid
Theory that life came from non-living things
Method used to solve problems
Where the heating test tube should be pointed
Basic units of measure for Volume
If on fire, what should be done
Studies animals
Non-essential to the individual's life characteristic
Vessel to hold and heat a liquid
Disproved the above using the gauze covered jar
An educated guess
What shouldn't be on top of a heating test tube
Basic units of measure for mass
Where to go if you get chemicals in your eyes
Studies plants
Type of reproduction found in amoeba and hydra
Instrument used to pick up small specimens
Also disproved it using the sealed boiled flasks of gravy
What the above is based on
What should be on your eyes if you are heating a test tube
How tall are you in meters
Three conditions when goggles would be worn
Studies bacteria and viruses
Keeping the body in a balanced state
Device used to observe small specimens (not microscopic ones)
Father of Microbiology who disproves this theory
Your 5 senses allows you to do this
Where all the lab safety equipment are in the room
How many milliliters are in a liter
What to do if you break a piece of glassware
Looks at how living things interact with their environment
Building up process
Measures the mass of an object
Special type of flask used by the above
Keep these out of the above
How you should be dressed when doing a lab with an open flame
What part of a meter is a cm?
Where all glassware should be on your lab tables
Studies how traits are passed from one generation to the next
Breaking down process
Used on top of a glass slide with a wet mount
What was the big difference between Spallanzani's work and Pasteur's
The final answer to your problem
Caution should always be exercised when working with this
What does um stand for?
How to pull out an electrical cord from the socket
Studies the form of the human body
The fact that you are getting scared about taking this test means that you are …
What units a graduated cylinder measures in
Life comes from life
That which changes in an experiment
The last thing you should always do after performing a lab
1cm3 = ______
What to use when handling something hot
Studies how living things are classified
All the chemical reactions in an organism

44. The right tool is what is important Where babies really come from
Our method
The Way we do things here
Measure this
Watch it or the Safety Police will get you
They're a What?
Life is a Wonderful Thing
Graduated cylinder
Spontaneous generation
Scientific method
Away from all people in lab ml
Screamed that you are on fire, stop, drop and roll and someone will bring a fire blanket
Zoology
Reproduction
Beaker or flask
Redi
Hypothesis
A stopper g
eye wash station
Botony
Asexual
Forceps
Spallanzani
Basic research and prior knowledge
Goggles
</= 2m
Chemicals, heating something, glassware
Microbiology
Homeostasis
Hand lens
Pasteur
Observations
On the side of the room
1000ml in a m
Let the teacher know. Do not touch it
Ecology
Anabolism
Balance
Swan necked flask
Opinions and inferences
Hair tied back and sleeves rolled up
1/100 or 100th
Away from the edge of your table
Genetics
Catabolism
Cover slip
Pasteur allowed oxygen to get in
Conclusion
Chemicals
micrometer
Gently unplug by the plug, not the cord
Anatomy
Irritability
Biogenesis
Variables
Clean up everything and put all away
1ml
Test tube holders, tongs or mitts
Taxonomy
Metabolism