Download The dog`s saliva must prevent the growth of

1st Quarter Test Review
1. A student noticed that when a dog is cut, the dog periodically licks its wounds. Usually after a few days, the
wound begins to heal without ever showing signs of infection. The following steps outline the student's line of
reasoning:
a. I wonder why the dog's wound doesn't become infected.
b. The dog's saliva must prevent the growth of infection-causing bacteria.
c. I'll obtain a bacterial culture and grow the same kind of bacteria in two identical culture dishes. Once the bacteria start growing,
I'll add dog saliva to only one of the dishes and leave the other alone. I'll cover both dishes. Then I'll observe what happens each
day for a week.
d. Even after adding the dog saliva to one of the dishes, the bacteria continued to grow in both dishes over the course of the
week. However, the bacteria in the treated dish grew more slowly than the bacteria in the untreated dish.
e. I think I'll try something else. I'll start with two identical culture dishes, as before, and use the same kind of bacteria in each
dish, but this time I'll treat one dish with dog saliva before I add the bacteria. I'll observe what happens each day for a week.
What was the student’s hypothesis?
The dog's saliva must prevent the growth of infection-causing bacteria
Which step described the experimental set up?
C
Identify the control
The dish that he left alone without saliva
What is the independent variable?
The dog's saliva
What is the dependent variable?
the growth of infection-causing bacteria
What data did the student collect?
The bacteria continued to grow in both dishes over the course of the week. However, the bacteria in the
treated dish grew more slowly than the bacteria in the untreated dish.
What is a possible conclusion from this experiment?
That the dog's saliva did slow down the growth of infection-causing bacteria
Is that conclusion a fact or an inference?
inference
2. What is the purpose of a hypothesis?
State a testable explanation for the situation that you observed
How do you test it?
With an experiment
3. What is the difference between the control group and the experimental
group?
Control – all conditions are kept the same
Experimental – conditions match that of the control except for
the one factor being tested
4. In your seed lab, what was the control group? What were the
experimental groups?
Control – tap water
Exp – pond and sea water
5. How does sample size affect the results of an experiment?
A large sample size increases the reliability of results and
decreases the effect of errors on the outcome
6. What were the independent variables in your seed lab?
Time, types of water
7. List and describe the levels of organization in Biology.
Atoms – smallest unit that makes up an element
Molecules – two or more atoms together
Organelle - Structure within a cell that has a specific function for
cell survival
Cells – basic structural unit of an organism
Tissue – a group of the same type of cell working together
Organ – a collection of tissues that perform a function in an
organism
System – a group of organs working together for a common
purpose
Organism - one individual that has all the characteristics of life
Population - a group of organisms
Community – a collection of populations
Ecosystem - several communities including the abiotic
components of the environment
8. Which level of organization in Biology is the simplest?
Atom
Which is the most complex?
Ecosystem
9. How do autotrophs obtain energy?
Capture energy from the sun
How do heterotrophs obtain energy?
They must get energy by consuming food
10. If a system had four trophic levels, how much energy would be
available at each level if the producers (autotrophs) had 10,000 kcal of
energy?
10,000 kcal  1,000 kcal  100 kcal  10 kcal
11. Why is only 10% of the energy of the first trophic level available to
the animals that feed on autotrophs?
Some energy is used my the organisms at each level and some is
lost as heat
12. Why would a top predator have higher levels of a contaminant than its
prey that was actually exposed to the contaminant?
The contaminants bioaccumulate in the bodies at each level
13. What is the difference between a habitat and a niche?
Habitat - The place where an organism lives
Niche - The role an organism plays in its environment
including all of the biotic and abiotic needs for survival.
14. Can two organisms share a habitat?
Yes
Can they share a niche?
No – they will compete and try to drive the other out
15. Create a food chain and identify the producer, primary
consumer, secondary consumer, and tertiary consumer.
Lettuce –
rabbit –
fox –
bear
Producer – primary cons. – secondary cons. – tertiary consumer
16. What happens to two organisms when they compete for the
same niche?
they will compete and try to drive the other out
17. What is the difference between density-dependent and densityindependent factors? Give example of each.
Density-Dependent - increased effect as population increases
(more organisms, more risk)
Ex. Disease, Competition, Parasites, Predation
Density-Independent - affect all populations regardless of
their density (more organisms, same risk)
Ex. Temperature, storms, natural disasters, drought,
habitat destruction, pollution
18. Describe and give an example of each of the following
symbiotic relationships:
Commensalism – One benefits, the other is unaffected
Spanish moss, barnacles on a whale, burdock seeds
Mutualism – Both benefit
Acacia tree and ants, lichens (algae and fungus)
Parasitism – One benefits, the other is harmed
Tapeworms, heartworms, bacteria, ticks, fleas, mistletoe
19. What is succession? Draw a simple drawing depicting succession.
Natural changes and species replacements in communities of an
ecosystem
20. What is primary succession?
When organisms colonies new areas (that have never had life)
Give an example.
Lava destroying all life in its path and forms new land
An avalanche exposes new areas and ledges
A city street has never before had life growing from it.
21. What is secondary succession?
When organisms colonize an area that once had life that was
wiped out
Give an example.
natural disaster or human actions disrupting or destroying a
community
22. If you stopped mowing your lawn, how would that
affect the plant and animal populations that used to
live there?
The conditions may become unsuitable for
certain organisms and plants and become more
suitable for other. It may start supporting larger
plants and animals.
23. The stable ecosystem established after a succession is
called a ________________.
Climax community
24. Energy ________ through an ecosystem while
nutrient materials are __________.
Flows, cycled (recycled)
25. Describe what happens to water in the following processes of
the water cycle.
Evaporation – water leaves lakes, oceans and other bodies and enters
the atmosphere
Transpiration – water is lost from the leaves of plants and enters the
atmosphere
Condensation – water in the atmosphere condenses to form clouds
Precipitation – water in the clouds falls to the earth
Run-off – water flows from the surface of the earth into bodies of
water
26. Who is responsible for the nitrogen fixation that occurs in the
nitrogen cycle?
Nitrogen-fixing bacteria
27. In the carbon cycle, what type of organism depends upon the
carbon dioxide in the atmosphere?
plants
28. Compare and contrast Prokaryotic and Eukaryotic cells.
Prokaryotes
Do NOT have membrane-bound organelles
(like a nucleus, mitochondria, chloroplasts, ER, etc)
Eukaryotes
DO have membrane-bound organelles
29. What organisms fall into the category of Prokaryotes?
Bacteria
30. How do you determine the total magnification of a microscope?
objective lens x eye piece = total magnification
What would the total magnification be if you were using the 10x
objective lens? 40x?
100x, 400x
31. List the three parts of the Cell Theory.
1. All organisms are composed of one or more cells
2. The cell is the basic unit of organization of organisms
3. All cells come from preexisting cells
33. Describe the function of each of the organelles below.
Cell membrane
- Boundary of the cell
- Controls what goes in and out of the cell through the
selectively permeable membrane
- Maintains cell’s homeostasis
Cytoplasm
A semi-fluid material that contains the molecules and
organelles in the cell
Nucleus
- Functions in the genetic control of the cell
- Chromosomes made of DNA
Nuclear memembrane
- Surrounds the nucleus
- Regulates the materials that pass between the nucleus
and the cytoplasm
Mitochondria
Site of cellular respiration, a process that provides
the cell with energy
Endoplasmic Reticulum
ER is a complex, extensive network that
transports materials throughout the inside of the
cell
Golgi Apparatus
Modifies, collects, packages, and
distributes molecules within the cell or
outside the cell
Ribosomes
Site of Protein synthesis
Cell Wall
Gives the cell added support and protection
Chloroplasts
Contain the pigment chlorophyll that absorbs
energy from sunlight to convert carbon dioxide
and water into sugar during photosynthesis
Lysosomes
Small organelles containing digestive enzymes to
break down food particles, worn out organelles,
bacteria, and viruses into particles that can be
used by the rest of the cell
34. What might the presence of many mitochondria indicate about a
cell?
That cell most likely needs a great deal of energy to perform
its functions
35. Answer the following questions about the graph above.
How much rain fell in Mar of 1989?
~6 inches
How much more rain fell in Feb of 1990 than in Feb of 1989?
~2 inches
Which year had the most rainfall?
1989: 4+2+6+8+6+2 = 28 inches
1990: 2+4+2+7+5+8 = 28 inches
What is the wettest month on the graph?
April