Transcript Document 272011

Written Final Review
What are the parts of an experiment?
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Observation
Hypothesis
Experiment
Data Collection
Conclusion
Retest
Smither’s Juice
• Smithers thinks that a special juice will increase the productivity of
workers. He creates two groups of 50 workers each and assigns each
group the same task (in this case, they're supposed to staple a set of
papers). Group A is given the special juice to drink while they work.
Group B is not given the special juice. After an hour, Smithers
counts how many stacks of papers each group has made. Group A
made 1,587 stacks, Group B made 2,113 stacks.
• Independent Variable
▫ Special juice
• Dependent Variable
▫ How many stacks are made
• Control Variable
▫ No special juice given (normal group)
Larry’s Muscle Cream
• Larry was told that a certain muscle cream was the newest best thing on the
market and claims to double a person’s muscle power when used as part of a
muscle-building workout. Interested in this product, he buys the special muscle
cream and recruits Patrick and SpongeBob to help him with an experiment.
Larry develops a special marshmallow weight-lifting program for Patrick and
SpongeBob. He meets them once every day for a period of two weeks and keeps
track of their results. Before each session, Patrick’s arms and back are lathered
in the muscle cream, while SpongeBob’s arms and back are lathered in regular
lotion. Larry also lifts weights, but does not put any cream on his arms.
Larry’s Muscle Cream
• Initially Patrick lifted 18 pounds, SpongeBob lifted 5 pounds and
Larry lifted 10 pounds. After week 1 Patrick lifted 24 pounds,
SpongeBob 9 and Larry 14. After week 2 Patrick lifted 36 pounds,
SpongeBob 11 and Larry 17.
Weight Lifted
Time
Initial Amount
After Week 1
After Week 2
Patrick
18
24
36
SpongeBob
5
9
11
Larry
10
14
17
Larry’s Muscle Cream Experiment Results
Time
Larry’s Muscle Cream
• What would Larry’s hypothesis be?
▫ If I use the muscle cream, then I will be able
to lift more weight because the cream
muscle-building vitamins.
• Which person is in the control group?
▫ Larry is the control.
• What is the independent variable?
▫ The independent variable is the use of
muscle cream.
• What is the dependent variable?
▫ The dependent variable is the weight lifted.
• What should Larry’s conclusion be?
▫ Larry’s hypothesis; If I use muscle cream,
then I will be able to lift more weight, was
not upheld. Patrick used the muscle cream
and saw a 100% increase in muscle power,
but Spongebob and Larry did not use muscle
cream and saw a 120% and 70% increase in
muscle power respectively. Therefore, the
use of muscle cream and increased muscle
power are not related.
Lisa and Rogooti
 Lisa is working on a science
project. Her task is to answer the
question: "Does Rogooti (which is
a commercial hair product) affect
the speed of hair growth". Her
family is willing to volunteer for
the experiment.
 Set up an experiment to test this.
 What would the independent
variable be?
 The use of rogooti.
 What would the dependent
variable be?
 Amount of hair growth.
 What would the control be?
 The family members that do NOT get
Rogooti
What is the purpose of a control?
• Thirty students wore a magnetic
bracelet designed to make them
more intelligent. They were all
given a test, and they all got C’sA’s. Most students reported that
they felt smarter with the bracelet
on. It works!
▫ Right?
 A control is used for
comparison.
 A control also helps validate
experimental results.
Organisms in the Environment
• Apex predator
▫ The top predator in an ecosystem.
• Abiotic
▫ Non-living factors like sunlight or rocks.
• Biotic
▫ Living factors like plants and animals.
• Trophic Levels
▫ The level of feeding relationships in
ecosystems.
• Energy Pyramids
▫ A visual representation of the amount of
energy available at each trophic level.
• Producer
▫ An autotroph or plant that can produce its
own food from inorganic (sunlight or
chemical) substances.
• Herbivore
▫ An organism that eats only plant material,
like a giraffe.
• Carnivore
▫ An organism that eats only meat, like a lion.
Population, Community, Ecosystem
• Population
▫ A population is all the
organisms of the same species
living in the same place.
 Like a population of grey mouse
lemurs.
• Community
▫ Different species all living
together within an ecosystem.
 Like the grey mouse lemur and
crickets.
• Ecosystem
▫ All the organisms living
together within an ecosystem
along with the abiotic factors
(sunlight, temperature, etc.)
that surround them.
Population Fluctuations
• A population will
increase if there are
more births than deaths.
▫ A population will also
increase if there are
more organisms
immigrating into it.
• A population will
decrease if there are
more deaths than births.
▫ A population will also
decrease if there are
more organisms
emmigrating out of it.
Energy Pyramids and Trophic Levels
The hawk is a
carnivore, a
secondary
consumer, and
the third
trophic level.
The rabbit is an
herbivore, a
primary
consumer, and
the second
trophic level.
Grass is a
primary
producer and
the first trophic
level
1 kcal
90% of all energy
is lost from one
trophic level to
the next, leaving
only 10% to be
passed up the
food chain.
10 kcal
100 kcal
Widows Peak
• Some people have a widows peak (hair line that meets in a point at the
forehead), where others have no widows peak.
▫ A husband and wife both have a widows peak, but two of their
children do not.
 Is the widow’s peak a dominant or recessive allele?
• There are four scenarios for the parents genetics.
▫ QQ x QQ
 If this were the parents genetics, a widow’s peak would be dominant (because that’s
what the parents display).
 It would also mean that both children would have a widows peak because they
could only inherit dominant genes.
▫ qq x qq
 If this were the parents genetics, a widows peak would be recessive (because that’s
what the parents display).
 It would also mean that both children would have a widows peak because they
could only inherit recessive genes.
▫ QQ x qq
 In this possibility, only one parent would have a widow’s peak, because it would be
either dominant (QQ) or recessive (qq).
▫ Qq x Qq
 If this were the parents genetics, their children could inherit QQ, Qq, or qq.
 If the parents genetics are Qq, and they display a widows peak, then it is a
dominant trait.
▫ If their children inherit the qq alternative, they will have straight hairlines.
Widow’s Peak
Possibility 1
Possibility 2
Possibility 3
Q
Q
q
Q Q Q
Q Q
Q Q Q
Q q
q q q
qq
Q Q Q
Q Q
q Q q
qq
q q q
qq
Each parent would
display the
dominant gene for
a widows peak, but
also have a
recessive gene for a
straight hairline.
Their children
would have a 25%
chance of getting a
straight hairline.

Q
• Both parents
would have
dominant
genes for
widows peak
and any child
they had
would also
have widows
peaks.

q
q
Both parents
would have
the recessive
genes for
widows peak
and any child
they had
would also
have widows
peaks.
Eye Color
 Brown eyes are dominant
(B), blue eyes are
recessive (b). Oliver is
heterozygous for brown
eyes and his wife Olivia is
heterozygous for brown
eyes. They have 4
children. Show the
genotypes, genotypic
ratios, phenotypes, and
phenotypic ratios for this
cross.
 Since Oliver and Olivia
are both heterozygous for
brown eyes, they will
both have a Bb
genotypes.
Eye Color
Oliver: Bb
Olivia: Bb
•
•
•
•
B
b
B
B B
Bb
b
B b
bb
The genotypes are BB, Bb, and bb.
The genotypic ratio is 1(BB) : 2 (Bb) : 1 (bb) or 1:2:1
The phenotypes are brown eyes and blue eyes.
The phenotypic ratio is 3 (brown) : 1 (blue) or 3:1
Evidence for Evolution
• 3.Comparative Anatomy
Body structures without similar origins, but
used for the same purpose are called
analogous structures.
▫ Includes vestigial structures.
 Structures that used to have a
purpose, but no longer do.
 Shows the evolutionary
history of an organism.
Body structures with similar origins, but used for
different purposes are called homologous
structures.
Baleen Whales are born
with pelvic bones,
although they do not
walk on land.
Evidence for Evolution
• 1. Fossils
▫ Provide a look into the
history of life on Earth.
▫ Allow scientists to follow
changes in the life history
of organisms.
• 2.Radiometric Dating
▫ Has an error rate of less
than 10%.
▫ Allow scientists to
accurately date the age of
fossils.
Ichthyosaurs appeared about 250 mya and
disappeared about 90 mya and grew to
about 6.6-13 feet long! They resemble
modern day dolphins.
Evidence for Evolution
• 4. Embryology
▫ Embryos of many organisms
resemble each other at
certain stages of their
development.
 Shows common ancestry.
• 5. DNA and Protein
Comparisons
▫ The DNA of many organisms
have similarities to each
other.
 The more alike two DNA
and protein structures are,
the more related two
organisms are.
 This points toward
common ancestry.
There is a dolphin, cat, and
human baby in these pictures.
Can you tell which is which?
Appendix Issues
• A teenage girl has her appendix
removed during an operation. 24
hours later the girl begins to run a
fever, which quickly rises. She has
contracted an internal infection
(caused by the bacteria
Staphylococcus aureus) during the
surgery. Will she survive the
infection?
Appendix Issues
• 1925
▫ The girl becomes delirious
from fever; in a few days,
she dies. No antibiotics
invented.
 In 1925, because there were
no antibiotics to combat the
bacteria, the young girl dies.
Staphylococcus aureus is
perfectly suited for living
inside and infecting the
human body due to natural
selection.
Appendix Issues
• 1945
▫ The girl receives an injection
of the antibiotic penicillin.
Within 24 hours, her fever is
reduced; she is released from
the hospital and is on her way
to recovery.
 With the advent of penicillin,
an antibiotic, doctors finally
had a surefire way to combat
Staphylococcus aureus. As a
result, it was used on many
cases of infection and saved
many lives.
Appendix Issues
• 1965
▫ The girl receives an injection of the antibiotic
penicillin, within 24 hours, the girl dies.
 Because penicillin had been used since 1945,
it put selective pressure on Staphylococcus
aureus. Staphylococcus aureus naturally
had variations within its population, along
with randomly occurring mutations in its
DNA, which had more resistance to
penicillin. These versions of Staphylococcus
aureus had higher fitness than older, more
susceptible versions. Over time, those
variations were selected for. As a result,
penicillin became more and more useless in
the face of a newly adapted, more resistant,
strain of Staphylococcus aureus.
Bacteria vs. Viruses
Bacteria reproduce through
binary fission—a form of
asexual reproduction.
A virus reproduces by invading a
host cell and taking over the cell
causing it to make copies of the viral
DNA/RNA. It destroys the host cell
releasing new viruses.