Introduction to Living Environment!

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Introduction to Living Environment!
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What is Science?

• It is the body of knowledge and the way of
  knowing things
• What is the difference between English as a body
  of language and Science?
• How do we know things?

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Living Environment

• Aka Biology
• The study of living things in the environment
• What kind of things?

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The Laboratory

• Always wear goggles when using chemicals.

• When heating a material in a test tube

• point tube away from you

• never put a stopper in the tube

• glassware

test tube
beaker
Graduated cylinder- always read volume at
meniscus
flasks
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• Lab Safety Rap
• Current EVENTS- Lab Safety

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DO NOW

• 1. What is the difference between a flask and a
  beaker?
• 2. What is a meniscus?
• 3. Why is lab safety so important?

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Laboratory equipment

• Centrifuge/ultracentrifuge-

• machine that spins specimens at high speeds which
  separates the materials w/in the specimen
  according to density

• heaviest materials settle to the bottom

• can be used to separate out cell parts
• (nucleus from ribosomes)

• Micro-dissection Instruments-

• surgical instruments that cut apart microscopic
  things
• (ex. removing a nucleus from a cell)

Incubator-

• keeps specimens warm (premature babies, cell
  samples)

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Chromatography-

• chrom color

• process in which a substance (ink, chlorophyll)
  is separated into its component parts/colors

• The rate at which the components move/separate
  are unique to the substance being tested

• By comparing the separation of the unknown
  substances to that of a known substance, an
  identification may be made.

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Triple Beam Balance

• Measures in grams
• Mass is different than weight!

Ruler

• Remember to use the metric (cm) side of the
  ruler, not the inches side! 1 cm 10 mm

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Gel Electrophoresis

• Used in crime investigation, paternity testing
  and genetic research

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How do we study Science?

• Define the problem/ question
• Hypothesis to explain
• Test with a controlled experiment
• Generate data to form inferences and conclusions

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Conducting an Experiment

• A question you are trying to answer or problem
• you want to investigate

• A control the setup that remains the same
  through the experiment provides a comparison

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• A variable-

the element/factor that changes in the experiment
(amount of sun, water)
-a valid experiment tests only ONE variable
at a time
variable that does not depend on a factor in the
experiment (ex. time, days)

• independent-

relies on the independent variable ex) plant
growth depends on time, time does not depend on
plant growth

• dependent-

• A hypothesis-

possible answer to the question you are asking
often posed as an ifthen statement
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• An observation-

what you see happening provides data for analysis

• A conclusion-

Sums up the findings. Scientists use the data to
determine whether the hypothesis was supported or
refuted

• Sample size-

Refers to the of organisms being tested. The
larger the sample size, the more valid the
results are.
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What factors make a good experiment?

• Variables
• Control
• Large sample size
• Repeating the experiment with the same results as
  were previous found- what does this do?

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Measurements

• Length
• Mass
• Volume
• Temperature

• km, cm, mm

• Grams

• Liters, milliliters

• Celsius, Kelvin
• Have the same scale
• Celsius is based on where water freezes (0 C)
  and boils (100 C)
• Kelvin is based on absolute zero

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Graphing Basics

• Scientists record lab observations and
  measurements in an orderly manner
• Using data tables and line graphs (sometimes bar
  graphs too!)
• Line graphs are used to show relationships
  between two variables.
• independent variable- horizontal, or x-axis
• Dependent variable- vertical, or y-axis