Transcript Quarter 1 HSA Review Session - Mr-Paullers-wiki

Week 1 HSA Review
Session
Scientific Method &
Inorganic/Organic Molecules
Experimentation
Scientific Method
Scenario: For your science fair experiment, you want to determine how the amount of sunlight affects the size
of tomato plants. You believe that the more sunlight the plants receive, the more they will increase in size. To
perform your experiment, you keep one set of tomato plants under a light for 24 hours a day, another set of
plants under a light for 12 hours a day, and a third set of plants without any sunlight, and a fourth set of plants
outside where the amount of light changes daily.
Definition
Hypothesis
Independent
Variable
Dependent
Variable
Control Group
Experimental
Group
Bias
Using Scenario
Graphing
Create a proper graph based on the
following data:
A student performed an experiment to
determine the relationship between air
temperature and growth in plants. She divided
36 seedlings into six groups and grew each
group at a different temperature. She recorded
the average height of the plants in each group
after a four-week period. Her results are shown
below.
Temperature (°C):
Average Height (cm)
6
15
12
20
18
36
24
52
30
20
36
16
Question 1
Use the information and the chart below to answer the following items.
Several students are conducting an experiment to test the effect of exercise on heart rate.
Students do 20 sit-ups in one minute of exercise. The data chart below shows the heart rate at
one-minute intervals for each student.
1. The students decide to ignore any results that were too far above or below their prediction.
They repeat these trials until a value closer to their prediction is obtained. The students’
decision to ignore data and repeat trials affects the experiment by
A. introducing bias
B. decreasing controls
C. increasing accuracy
D. eliminating variables
Question 2
Use the information and the chart below to answer the following items.
Several students are conducting an experiment to test the effect of exercise on heart rate.
Students do 20 sit-ups in one minute of exercise. The data chart below shows the heart rate at
one-minute intervals for each student.
2. Which of these is the dependent variable?
A. time
B.
heart rate
C. type of exercise
D. number of sit-ups
Question 3
Use the information below to answer the following item.
Methyl mercury is a toxic substance that can harm the nervous system. Some fish are contaminated
with high levels of methyl mercury. In many places, these fish are an important food source.
Experiments are being conducted to determine how many meals of contaminated fish can be safely
consumed. The table below shows the concentration of methyl mercury in the fish and the number of
meals that can be safely consumed per month.
The data collected during this experiment are summarized in the graph below.
The graph has been constructed incorrectly. Which of these needs to be corrected in order to improve
the graph?
A. The axes are labeled with inappropriate intervals.
B. The dependent and independent variables are on wrong axes.
C. The title is inconsistent with the investigation.
D. One or both axes are missing units.
Question 4
Students tested two cleansers for their effectiveness against bacteria. In their
experiment, each cleanser was used on two different household surfaces. The
students took samples from each surface before and after using each cleanser. Then
they transferred each sample to a culture medium. The students counted the number
of bacterial colonies that grew on each culture medium. The results of their test are
shown in the table below.
4. Which of these would be the best control for their experiment?
A. Use only Cleanser 1 on both sinks and counters.
B. Use Cleanser 1 on the sinks and Cleanser 2 on the counters.
C. Test the number of bacteria on the counters and sinks after scrubbing without using
cleansers.
D. Test the number of bacteria on the counters and sinks without scrubbing with
cleansers.
Water
Properties of Water
Universal Solvent =
Is able to dissolve most chemicals. Water
is a universal solvent because it dissolves
more substances than any other solvent.
When water is a solid (ice) it
Less Dense as a Solid = floats on liquid water.
Polar (Polarity) =
Cohesion &
An uneven distribution of charge. One
area of the molecule is positive and the
other is negative.
Cohesion – attraction of LIKE molecules to
each other.
Adhesion
=
Adhesion - attraction of UNLIKE molecules
to each other.
Surface Tension =
The surface film (“skin”) on the top of
a liquid caused by molecular
cohesion.
Non living; not made of
Inorganic molecules =
carbon.
pH
= Relative concentrations of hydronium ions (H+)
and hydroxide ions (OH-) in a solution.
Question 5
Use the information and the drawing below to answer the following item.
The pitcher plant is a carnivorous plant that consumes various small organisms such as
spiders and frogs. The pitcher plant is often found in areas with soil that is very acidic and
contains few nutrients. The pitcher plant consumes organisms that help supply the plant
with nutrients that are not in the soil. A diagram of the pitcher plant is shown below.
In which soil pH range are pitcher plants most likely found?
A. 4.5–5.5
B. 7–8
C. 10.5–11.5
D. 13–14
Question 6
Water dissolves many substances. This occurs
because water has
a. surface tension
b. polarity
c. specific heat
d. cohesion
Question 7
When the cells of most organisms freeze, they burst.
Which property of water causes this to occur?
a. Water is a universal solvent.
b. Water changes temperature rapidly.
c. Water is less dense as a solid than as a liquid.
d. Water is a nonpolar molecule.
Macromolecules
Organic molecules =
Macromolecule
Carbohydrate
Lipids
Building Blocks
Monosaccharide
Fatty Acid
Function
Energy
Plant cell wallstructure
Examples
Sugar
Glucose
Starch- polysaccharide
cellulose
Long term energy storage
Cell membrane component
Wax
Fat
Phospholipid
Oil
Macromolecule
Building Blocks
Function
Protein
Nucleic Acid
Amino Acid
Nucleotide
(A,C,G,T,)
Structure of hair,
nails, skin & muscles
Store genetic
information
Catalysts
Examples
Meat
Enzymes
DNA
RNA
Question 8
Which statement describes the major role of lipids
within a cell?
a. They cause DNA to replicate.
b. They move RNA in the cytoplasm.
c. They catalyze chemical reactions in the cell
cytoplasm.
d. They are the main structural components of
membranes.
Question 9
A dog gets many nutrients from its food including
amino acids. Which of these can be built directly
using the amino acids?
a. proteins
b. carbohydrates
c. lipids
d. minerals
Question 10
Which of these are the repeating units that form a
DNA molecule?
a. fatty acids
b. nucleotides
c. amino acids
d. chromosomes
Question 11
Most carbohydrates in the human body are
a. used as building blocks for proteins
b. used as catalysts for reactions in cells
c. consumed as a source of energy
d. not easily absorbed into the bloodstream
Question 12
Glucose is a building block of carbohydrates. Which of
these best describes glucose?
a. nucleotide
b. protein
c. monosaccharide
d. lipid
Question 13
The characteristics listed below can be used to describe
some molecules.
1)
2)
3)
4)
5)
inorganic
supplies energy and fiber
component of plant cell walls
part of DNA
made of nucleotides
Which of these sets of characteristics describes a
carbohydrate?
a. 1–3–5
b. 2–3–4
c. 2–4–5
d. 1–3–4