EOC Unit 1 Study guide

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)
What is the difference between a hypothesis and a theory?
Hypothesis is a prediction of the expected results before an experiment.
A theory is an explanation of how and why something occurs and is supported by all of the evidence
available.
What is the difference between an independent variable, dependent variable, & control variable? Be
sure to be able to identify each in an example experiment.
Variables:
Independent – something “I” change; the 1 difference between the 2 groups in an experiment
Dependent – measured
Control – all of the variables that must be kept constant so that there is only 1 independent variable
What is biology?
Study of life
Define in order the hierarchy of organization (molecule..organelle…cell…) and be able to cite examples
for each category.












Biosphere – All environments on earth that support life
(Basically, the Earth and the sky
above it that has living things occupying it.)
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 of up one or more cells)
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
What are the 7 characteristics of life?
1. Organization and cells, 2. homeostasis, 3. response to stimulus, 4. change over time
(evolution), 5. growth and development, 6. reproduction, 7. Metabolism
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 (either they have the disease or do not)
dependent variable: Symptions (measure what all is wrong with them)
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: Petri dish with no mold
Experimental group: Petri dish with mold
independent variable: Presence of mold
dependent variable: growth of bacteria
control variables: type of bacteria grown, size of container, length of time kept in the petri
dish, 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
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
5. The role of a control in an experiment is to what?
Control group: used for comparison against experimental group
Control variables: all variables kept constant to ensure there is only 1 independent variable
6. Label the chart with the correct organizational level.
A: Biosphere, B: Biomes, 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: Study Program
DV: Graduation Rates
“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.
So that you can compare the results from your experimental group to something (see the difference
the independent variable made)
9. What is the difference between a community and a population? How is an ecosystem different?
Population: 1 species in an area
Community: All the species in an area
Ecosystem: All of the biotic factor (the community) as well as all of the abiotic factors (sun, water,
etc.) 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)?
1. Title, 2. Scale, 3. Label X-axis with unit, 4. Label Y-axis with units, 5. Key (Legend)
11. What is the SI unit for the following measurements?
a), mass, b) length, c) temperature, d) volume, e) area, f) density
a. kilogram (kg), b. meter (m), c. Kevlin (K), d. milliliters (ml), e. meters squared (m 2), f. grams /
milliliters (g/ml),
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)
13. 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
 Write a hypothesis (in proper format) for the company with regards to this experiment.
If opening stores later in the day results is better for business, then there should be a greater profit
earned on days where the stores open later.

1)


What is the: 1) independent variable, 2) dependent variable, 3) control variables for this graph
Time of opening, 2) profit, 3) types of products available, location of store, etc.
Graph this data (remember to put the correct variable on each axis)
What should their conclusion be?
The store should open at 10 am.

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?
This would be unacceptable because there would be more than 1 independent variable (opening
times and prices) so it would be impossible to tell what caused the change in profits.
14. Calculate the mean of the following sets of value:
a) 5, 3, 4
4
b) 610, 610.6, 612, 616, 415
572.72
c) 0.003, 0.00004, 0.1, 1.3, 2.5
0.78
15. What is the difference in growth and devolpment vs. change over time?
Growth in development is the changes experiences from being a baby to an adult (HAPPENS IN 1
ORGANISM AND IN 1 LIFETIME).
Change over time is evolution (THE CHANGES SEEN IN POPULATIONS OF ORGANISMS OVER MANY
GENERATIONS)
16. What is meant by homeostasis? Provide an example of it in your body.
Maintaining a relatively constant internal environment despite a changing external environment
(body temperature remains at 98.6 degrees if it is 100 degrees or 30 degrees outside)
17. What is a response to a stimulus? Provide an example of it in your body.
Your body reacting to a change in an external stimulus (sweating when it is hot, eyes dilating or
constricting depending on the amount of light in the room)
18. Are viruses considered living? Why or why not?
No, they are not made of cells.