biology unit 2 - scientific process Flashcards
an issue about right or wrong applied to a biology issue
bioethical issue
recorded scientific information, gathered by observation
data
running an experiment in two groups for comparison, only the experimental group has the variable
controlled experiment
the factor you measure to see the effect of the independent variable (2 terms)
dependent variable
responding variable
the factors that are the same between the experimental group and the control group (2 terms)
constants
controlled variables
the half of a controlled experiment used only for comparison, not the experimental group
control group
the unit for temperature in metric system
- most commonly used in a lab
degrees Celsius (centigrade)
the SI unit for temperature
Kelvin
Why is Kelvin the preferred unit in SI?
absolute zero
What are the freezing and boiling points of water in Celsius?
freezing - 0 degrees Celsius
boiling - 100 degrees Celsius
a proposed explanation or a prediction about what will happen in a scientific experiment
hypothesis
a visual way of displaying data
graph
the SI unit for length
What tool measures length?
meter
meter stick or metric ruler
the metric unit for liquid volume
What tool measures liquid volume?
liter
graduated cylinder
the SI unit for mass
What tool measures mass?
kilogram
balance
1ml equals
1cc or 1cm3
the most important lab safety rule
follow the directions
Give two reasons why SI is the preferred system of measurement in science.
- universal
2. decimal system - based on tens (easier)
When scientists try to avoid having preconceived opinions about their experiments, they are avoiding what?
bias
a well-tested, well-supported big idea in science that unifies hypotheses, the dominant view - give examples
theory - cell theory, atomic theory, germ theory
a trait of scientists that makes them want to know
curiosity
a trait of scientists that makes them want evidence
When scientists question existing ideas and refuse to accept explanations without evidence, they are being what?
skeptical
a trait of scientists that allows them to see different points of view
When scientists are willing to look at ideas that are different from their own, they are being what?
open-minded
a trait of scientists that helps them come up with experiments
creative
applied science, science put to use
technology
a logical interpretation of data
inference
Why do scientists publish the results of their experiments? (2 reasons)
peer review
share ideas
What are the two major types of data, and how are they different?
qualitative - a judgment
quantitative - a number or quantity
Why do scientists prefer to quantify whenever possible?
measurements can be replicated and agreed upon
How can scientists improve their observations?
use tools like microscopes and rulers
What are two common sources of error in scientific tests?
human error
mechanical error
Why do we need a large sample size in a scientific experiment?
insures reliability
a logical interpretation of data
inference
What is the meaning of the root word hypo? Give an example word.
below - hypothesis
What is the meaning of the root word scientia? Give an example word.
to know - science
a body of knowledge gained by observation and experimentation, a way of knowing about the natural world
science
What are the goals of science?
to explain the natural world, find patterns, and make useful predictions
Name the two major types of microscopes, and give the advantage and disadvantage of each.
compound light microscope - can see living things but with less detail
electron microscopes - can see in great detail but must be dead
to notice using your senses
observation
What does the process of science usually begin with?
an observation that makes you ask a question
a proposed explanation that needs to be tested, a prediction or educated guess about what might happen in an experiment
hypotheses
Can a hypothesis ever be proven 100% correct?
no, it just gets supported by the current evidence
What does it take to disprove a hypothesis?
a single experiment
What should happen to a theory that holds true most of the time but can’t explain a particular event?
needs to be revised
How are hypotheses usually written?
if/then, if the independent variable is changed or manipulated in this way, then the dependent variable will respond in this way
a scientific test where only one variable is tested in at least two groups where one group has the variable and the other is identical except the variable and is used for comparison
controlled experiment
2 names for the factor being tested in a controlled experiment
independent variable
manipulated variable
the group being tested on
experimental group
an organized place to record data
data table
Name the 3 major types of graphs, and say what each is best for showing.
- circle or pie graph - shows parts of a whole
- bar graph - compares quantities or separate events
- line graph - shows continuous data, the relationship between two variables
When you look critically at the data to find patterns or look for sources of error to see if the data supports your hypothesis or not
analysis
Saying whether you support or refute your hypothesis
conclusion
when anonymous, independent experts look at your scientific process to see if it is high quality and to look for mistakes and bias
peer review
When scientists put their work in journals for others to read, they are doing what?
publish
Our choices about right and wrong are called what?
ethics
a well-tested, well-supported explanation in science that explains a broad range of observations and enables scientists to make accurate predictions about new situations
theory
What 4 things should be included in a good graph?
- title saying effect of IV on DV
- labeled axes with units
- units go over equally and up equally
- key
What is the name for the horizontal axis?
What is the name for the vertical axis?
horizontal - X
vertical - Y
Which axis often contains the IV?
Which axis contains the DV?
IV - X
DV - Y
What should the title of a graph be written like?
The Effect of (IV) on (DV)
What do you have to remember about the scale of the graph?
the units must go over evenly
the units must go up evenly
What system of measurement is used in science?
System Internationale - SI - newer version of metric system
What is the metric unit for time?
second
What is the relationship between length and volume?
volume is cubic length
What is the curve you must look for with liquid in a graduated cylinder, and how do you measure it?
meniscus - measure from the bottom
How is mass different from weight?
weight is affected by gravity and therefore changes.
How do you find the volume of an irregularly shaped solid?
water displacement
What is the freezing point of water in Kelvin?
boiling point?
273K
373K
the amount of matter in an object
mass
the amount of space an object takes up
volume
mass/volume
density
if something is more dense than a fluid, what happens?
sinks
if something is less dense than a fluid, what happens?
floats
kilo
1000
milli
.001
deci
.1
deca
10
hecto
100
centi
.01
the average of a set of numbers
mean
the middle value in a set of numbers
median
the most frequent value in a set of numbers
mode
the highest value minus the lowest value in a set of numbers
range
a mathematical expression used to represent a decimal number between 1 and 10 multiplied by ten, so you can write large numbers using less digits
scientific notation
Express in correct scientific notation: 61,500
6.15 X 10 4
Express in correct scientific notation: 0.0000568
5.68 X 10 -5
Express in standard form: 1.09 x 10 3
1,090
Express in standard form: 3.078 x 10-4
.0003078
How many significant figures does 5681.03 have?
6
How many significant figures does 0.53170 have?
5
Solve: 345.009 g - 23.009 g = ?
322.000 g
Complete the following problem: A piece of stone has a mass of 24.595 grams and a volume of 5.34 cm 3. What is the density of the stone? (remember that density = m/v)
4.61 g/cm3
Solve: 1.23 m x 0.89 m = ?
1.1 m 2
Convert the following measurement to scientific notation: 101 000 grams
1.01 x 105 g
How many significant figures are in the measurement 0.00130 cm?
three
What is the mean, median, mode, and range for the following number set: 7, 2, 10, 10, 10, 2, 7
mean - 6.9
median - 7
mode - 10
range - 8
What do you look through on a microscope (2 terms)
eyepiece or ocular lens
the microscope part that you put the slide on
stage
what adjusts the light on a microscope
diaphragm
the shortest objective lens on a microscope
scanning lens
the scanning, low, and high power lenses
objective lenses
What lens do you always start with when using a microscope
the lowest power
What should be used to clean microscope lenses? Why?
lens paper - prevent scratching
How should you carry a microscope?
2 hands, 1 on arm and 1 on base
Why should you only use fine focus on high power?
so you don’t cause the lens to hit the slide
What lets you turn from one objective to another on a microscpe
revolving nosepiece
How do you find total magnification on a microscope?
multiply ocular times objective
Why should you always cover a microscope?
to prevent dust from accumulating
What shape is the field of view on a microscope?
What happens to the field of view when the object is magnified more?
circle
gets smaller
What is the purpose of staining objects to be viewed under the microscope? What is a downside to staining?
more contrast to see
Why do you put the cover slip down on an angle with one edge first when preparing a wet mount?
prevent air bubbles
