Download Unit 1 (Introduction to Science) Study Guide KEY

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EOC Unit 1 Study guide - KEY
Note: A scientific theory is an explanation that explains HOW AND WHY something occurs
and is supported by ALL OF THE EVIDENCE AVAILABLE. (It is not just a “guess” or
somebody’s opinion. It is what is believed to be true based on all of what we know. The only
difference between a scientific theory and a scientific law is that a theory explains HOW it
happens while a law just says that it does happen)
1. What is the difference between a hypothesis and a theory?
Hypothesis is created before an experiment is ran. It is what the experimenter believes will be seen
during the experiment.
A scientific theory is an explanation that explains HOW AND WHY something occurs and is
supported by ALL OF THE EVIDENCE AVAILABLE. It is not a “guess” or somebody’s opinion.
2. What is the difference between an independent variable, dependent variable, & control
variable? Be sure to be able to identify each in an example experiment.
IV = the 1 difference between the control and experimental group. There can be only 1 because if
there was more than 1 then you would not know which variable caused the results you see. The
value is set by the person running the experiment. Independent variable is what “I” change.
DV = it is what is being measured, counted, observed, etc. There can be many dependent variables
depending on what you choose to measure.
CV = everything you have to keep constant during an experiment so that there is only 1
independent variable. If you allow a control variable to be changed then it becomes an independent
variable (and you have 2 of them so the experiment is no longer valid).
3. What is biology?
Study of life
4. Define in order the hierarchy of organization (molecule..organelle…cell…) and be able
to cite examples for each category.
Least specific (biggest thing)
 Biosphere – All environments on Earth that support life
(Basically, the Earth and the
sky above it that has living things occupying it.)
 Biomes – A group of ecosystems that have similar climates and communities
 Ecosystem – all living organisms in a particular area as well as the nonliving, physical
components they interact with (ex. Sunlight, water, etc.)
 Community – All living things in an area
 Population – Single species living in a single area
 Organism – Single individual
 Organ System – group of organs working together for a certain function
 Organ – 1 part of an organ system
 Tissue – group of similar cells that do a particular function for an organ
 Cell – Smallest unit of life (All living things are made up of one or more cells) (Can perform
all 7 characteristics of MRS. GOCH)
 Organelle – “organ” of a cell
 Molecule – cluster of atoms held together by chemical bonds
 Atom - basic unit of matter made of dense nucleus (protons and neutrons) with electron
cloud around it
Most specific (smallest thing)
5. What are the 7 characteristics of life?
MRS. GOCH
 Metabolism = conversion of chemical energy in the body (breaking down food to make ATP
and using ATP to build yourself)
 Reproduction = making babies
 Stimulus (response to a stimulus) = being able to react to a change in your internal or
external environment
 Growth and Development = growing/changing from a baby to an adult 1 ORGANISM 1
LIFETIME
 Organization of cells = all living things are made of cells and have been
organized/specialized toward their functions over time through natural selection
 Change over time (evolution) = populations change over many generations due to
differential fitness (differential reproductive success) POPULATIONS OVER
GENERATIONS
 *** Add because I forgot to put it on your sheet. Homeostasis = keeping your internal body
the same even though the external environment is changing
Practice questions:
1. In 1887 a strange nerve disease attacked the people in the Dutch East Indies. The disease was
beriberi. Symptoms of the disease included weakness and loss of appetite, victims often dies of heart
failure.
Find the…
independent variable: BeriBeri (1 difference in groups)
dependent variable: loss of appetite, death due to heart failure, etc. (what is being observed)
2. In 1928, Sir Alexander Fleming was studying Staphylococcus bacteria growing in a culture dish.
He noticed that a mold called Penicillium was also growing in some of the dishes. A clear area
existed around the mold because all the bacteria that had grown in this area had died. In the culture
dishes without the mold, no clear areas were present.
Fleming hypothesized that the mold must be producing a chemical that killed the bacteria. He decided
to isolate this substance and test it to see if it would kill bacteria. Fleming transferred the mold to a
nutrient broth solution. This solution contained all the materials the mold needed to grow. After the
mold grew, he removed it from the nutrient broth. Fleming then added the nutrient broth in which the
mold had grown to a culture of bacteria. He observed that the bacteria died.
Find the…
Control group: bacteria with no mold (no penicillin). The control group is always used as the
group for comparision
Experimental group: bacteria with mold (penicillin)
independent variable: mold or no mold
dependent variable: survival of bacteria
control variables: same size petri dish, temperature, light, duration of experiment, nutrients
in broth, etc.
3. Life is organized in a hierarchical fashion. Put the following sequence in order of hierarchy increasing
in complexity?
cell, molecule, organ system, organ, population, tissue, organism, ecosystem, community
Complexity increases as the level of organization gets larger because there is more involved.
Molecule, Cell, Tissue, Organ, Organ System, Organism, Population, Community, Ecosystem
4. The tree in your backyard is home to two cardinals, a colony of ants, a wasp's nest, two squirrels, and
millions of bacteria. Together, all of these organisms represent a what? Community (all the living things
in an area)
5. The role of a control (remember, if it only says “control” then it means control group) in an
experiment is to what? comparison
6. Label the chart with the correct organizational level. (Or in other words, write ecosystem, community,
etc. by the correct location)
A: Biosphere
B: Biome
C: Community
D: Population
E: Organism
7. Identify the independent & dependent variables in the following:
"There will be a statistically significant difference in graduation rates of at-risk high-school seniors who
participate in an intensive study program as opposed to at-risk high-school seniors who do not participate
in the intensive study program."
IV: Intensive Study Program
DV: Graduation Rate
“A nurse researcher wants to study the effects of yoga on blood pressure in hypertensive adults.”
IV: Yoga
DV: Blood Pressure
8. Explain why it is important to have a control group.
To have something to compare your results to. If you don’t have a control group, your results mean
nothing because you don’t know how the independent variable affected the group.
9. What is the difference between a community and a population? How is an ecosystem different?
Community = all living things in an area
Population = 1 species in an area
Ecosystem = all living (biotic) and nonliving (abiotic) factors in an area
10. What are the 5 parts that must be on every graph (4 of these must be on EVERY graph while 1 of
them will only be on graphs with 2 sets of data being shown)?
Title, X-axis labeled, Y-axis Labeled, Scale, Key/Legend (will only be needed with 2 or more sets of
data)
Remember, DRY MIX = DEPENDENT-RESPONDS-Y-AXIS
MANIPULATEINDEPENDENT-X-AXIS – Fix this – it says Y-axis on yours
11. What is the SI unit for the following measurements?
a), mass, b) length, c) temperature, d) volume, e) area, f) density
a) gram (or kilogram)
b) meter (kilometer, centimeter, etc.)
c) Kelvin
d) m3 if it’s a solid, ml if it’s a liquid
e) m2
f) g/m3 if solid, g/ml if it’s a liquid
12. Convert the following units:
a) 12 cm (centimeters) = _120,000__ um (micrometers)
b) 2,604.54 Mm (megameters) = _2,604,540___ km (kilometers)
c) 0.003 mL (milliliters) = _0.000003___ liters
d) 5.223 grams = _0.05223___ hg (hectograms)
*********Go back over staircase method
13. What is the difference in growth and development vs. change over time?
Growth & development = 1 individual in 1 lifetime growing up (due to mitosis)
Change over time = evolution – population of organisms changing over many generations (due to
differential reproductive success)
14. What is meant by homeostasis? Provide an example of it in your body.
Maintaining a constant internal environment even though the outside environment is constantly
changing. Ex. Temperature (shiver when you’re cold and sweat when you’re hot)
15. What is a response to a stimulus? Provide an example of it in your body.
Responding to a change in your environment. Ex. Eye dialating or constricting due to a change in
light.
16. A company believed that it may be able to generate more net profit by opening its stores at later times
because they had little business in the morning (and felt like they were wasting money paying employees
during this time. The company decided to do an experiment on this hypothesis by opening at a different
time each day for a week. Below is a data table showing their findings:
Day #
Time store opened
Profits
1
8 am
10,000
2
9 am
15,000
3
10 am
16,000
4
11 am
15,000
5
12 pm
13,000
6
1 pm
10,000
7
2 pm
9,700
a. Write a hypothesis (in proper format) for the company with regards to this experiment.
b. What is the: 1) independent variable, 2) dependent variable, 3) control variables for this graph
c. Graph this data (remember to put the correct variable on each axis)
d. What should their conclusion be?
e. If the store decided to change the prices of their merchandise each day in addition to opening at
different hours, would this be acceptable (in terms of being a valid experiment)? Why / why not?
A) If changing the store time gets more business then the business will see an increase
in profit. (REMEMBER IF, THEN)
B) Independent variable = time store opens, Dependent variable = profits, 3) Control
variables = same items sold, same prices, etc.
C) Bar graph
a. Title – Changes in profit due to change in opening times
b. Time on the x-axis (because it is independent variable)
c. profits on x-axis (because dependent variable)
d. Scale – x-axis (different day and time), y-axis ($1,000 intervals)
e. No legend
17. Calculate the mean of the following sets of value:
a) 5, 3, 4
3
b) 610, 610.6, 612, 616, 415
572.7
c) 0.003, 0.00004, 0.1, 1.3, 2.5
0.78