Labs
Suppose you study how speed affects the braking distance of a car. Match each part of the hypothesis phase with its output.
"Braking distance grows proportionally with speed." - 1 - Formulate the hypothesis "We will focus on how braking distance depends on speed." - 2 - Choose a scope "We will brake at various speeds but keep the car and other factors constant." - 3 - Make a strategy for testing the hypothesis
If nondisjunction occurs during meiosis II, how many of the daughter cells will have an incorrect number of chromosomes?
2
How long should hands be lathered while washing?
20 seconds The Center for Disease Control currently recommends 20 seconds of lathering under running water. This is about how long it takes to sing or hum the "Happy Birthday" song twice.
Bacteria from three different cultures were plated on agar plates containing ampicillin, an antibiotic. The number of colonies that grew on each plate can be seen in the graph below. If you assume that 100 bacteria were plated on each plate, what percentage of the bacteria on plate B were resistant to ampicillin?
3%
What is meant by osmotic pressure?
the amount of pressure needed to oppose osmosis
If the blood from an individual with type A blood is mixed with anti-A serum in one well and anti-B serum in a second separate well,
the anti-A serum well will show agglutination but the anti-B serum well will not.
Two agar plates, one containing the antibiotic streptomycin and one without antibiotics, are inoculated with E. coli. After incubation, the streptomycin negative plate has many bacterial colonies, while the streptomycin positive plate has only a few colonies. Samples of the colonies from the positive plate are placed on another positive plate, and after incubation many colonies grow. In this experiment, what is the selective agent?
the antibiotic streptomycin
If blood cells are placed in a hypertonic solution,
the cells will shrink due to water loss by the cell. A solution with a lower concentration of water and a higher concentration of solute in comparison to another solution it is called a hypertonic solution. If blood cells are placed into a hypertonic solution, the cell will lose water and shrink as the water moves down its concentration gradient from the cell into the solution.
What is photosynthesis? (Check all that apply).
the conversion of sunlight energy into chemical energy the process by which plants, some bacteria, and some protist use the energy from sunlight to produce sugar
An increase in temperature will cause an increase in diffusion rate because
the frequency and force of molecular collisions increases.
What is the definition of genotype?
the genetic makeup of an individual
All of the following are names that can be used to describe the major organs of the digestive system, except
the intestinal tract.
When brown iodine is exposed to starch it turns dark purple. In an experiment, you placed water and 10 drops of iodine inside a small bag made of dialysis tubing. Next, you placed the bag in a beaker with a cornstarch solution. The solution in the beaker turned dark purple. Select all that apply.
the iodine moved into the beaker iodine has a smaller molecular size than cornstarch the bag was selectively permeable Review the "Introduction" section and your lab data for this lab. Where did the color change occur? Within the beaker? Or within the bag? What had to move to cause this color change to occur? If one molecule moved through the bag but the other was unable, what does this tell you about the molecular size of these substances?
Cytochrome C is a protein found in all species, and functions in energy metabolism. The more closely related two different species are,
the more alike their cytochrome C amino acid sequences are.
What factors are responsible for the osmotic pressure of a solution?
the number and type of solute particles it contains
Which must be done before pouring liquid gel solution into the gel casting tray?
the open ends must be taped
Cytochrome C is a protein that functions in cellular respiration as part of the electron transport chain. It is frequently used to determine evolutionary relationships between different organisms because it is highly conserved (only differs slightly) between different organisms. A student researching evolutionary relationships between different organisms performed an ELISA test to analyze differences between cytochrome C proteins in different organisms. What is the independent variable in this experiment?
the organism
When determining the scope of an experiment, you need to consider (Select all that apply)
the outcome you will investigate. the factor that will vary. When determining how to test a hypothesis, you need to understand what outcome you are testing for; for example, in the pillbug experiment, you were testing to see if the pillbug would choose the chamber with the cornstarch. You also need to know what factors will vary; again, with the pillbug experiment, the variables were the cornstarch and the sand. Knowing the pillbugs weren't repelled from the sand you could surmise the movement to the cornstarch vs sand was caused by wanting to go into that chamber and not because they were repelled by the sand in the opposing chamber.
With the hemoglobin measurement we determine one of the important factors that determine _____.
the oxygen transport capacity of a person's blood
If oxygen is more concentrated outside a cell than inside
the oxygen will tend to diffuse into the cell.
What drives diffusion?
the random movement of molecules
What information did the movement of the bubble over a specified distance in the calibrated respirometer provide? (Check all that apply)
the rate of cellular respiration the volume of oxygen used
As molecular weight increases,
the rate of diffusion decreases.
When testing tonicity of red blood cells, if the solution became transparent after adding blood cells, you could assume
the solution was hypotonic and the cells had burst. If the blood becomes transparent then the red blood cells (RBCs) are not blocking the light, so the RBCs must have been destroyed if the solution is transparent.
All energy for living organisms originally comes from
the sun
Recessive alleles seem to vanish in some generations and reappear in later generations because
they are masked by a dominant allele.
In the genetic code, an amino acid is encoded by
three nucleotides.
Why were the shoot cuttings soaked in water?
to simulate a spring-time environment
Which of the following items will you need to make a wet mount?
transfer pipette clean slide tweezers
Fossils that have characteristics common to both an ancestral species and descendent species are called
transitional fossils.
Tube 4 had starch in it just like tubes 1 and 2 but did not show a reaction with the Benedict's reagent. Why not?
tube 4 didn't have amylase in it
In the presence of acid, phenol red turns yellow. As the pH rises (becomes alkaline), the solution returns to red. Based on this explanation, the uptake of CO2 by a plant in distilled water containing CO2 and a drop of phenol red would cause the water solution to
turn pink.
Which organism demonstrated unsuccessful reproduction?
unfertilized eggs
This image illustrates what correct safety practices? (Select all that apply)
use of gloves and eye protection tying back of long hair wearing of the lab coat In this image, the technician is wearing the correct personal protection equipment, and her lab bench is clean and free of unnecessary clutter
The strategy for the Antacids as Buffers simulation was to
use phenol red as an indicator to measure how many drops of HCl it takes to change the pH of each antacid solution.
What is the purpose of the sterile broth tube?
used to calibrate the spectrophotometer The spectrophotometer is calibrated using this sterile broth tube before measurements are taken with the growth samples.
Among the different forms of electromagnetic radiation emitted by the sun, which form is absorbed by plants for photosynthesis?
visible light
High heat capacity of water allows it to
warm and cool slowly.
The most effective antacid in the Antacids as Buffers simulation
was able to receive the most acid before the pH dropped significantly.
In the pillbug experiment, your hypothesis
was related to the environment pillbugs prefer.
Some consider osmosis a special case of diffusion because it only involves the movement of what substance?
water
Select all of the following that are products of cellular respiration.
water carbon dioxide
A student was measuring the height of plants grown with different types of fertilizer or with plain water. What is the independent variable in this experiment?
what the plant was watered with Independent variables are variables that scientists select to change within the experiment like different types of fertilizer. Dependent variables are variables that scientists observe in relationship to the independent variable like plant height.
When should the chemical fume hood be used?
when using hazardous chemicals Chemical fume hoods do not provide protection from infectious microorganisms. If working with BSL-2 microorganisms, a biological safety cabinet should be used.
When testing tonicity in potato strips, you soaked potato strips in different solutions. You were then able to determine the tonicity of the solutions based on
whether the potato was crisp or limp. The lab strategy was to place potato strips into two different solutions with different tonicities to see which potato strip becomes limp or rigid.
When a blood sample is centrifuged the buffy coat represents the
white blood cell and platelet percentage.
The antibodies related to the ABO blood group are located
within the plasma.
How does a phenol red-containing solution look if CO2 level is high?
yellow
Match each pigment with its color.
yellow-orange - 2 - carotene yellow - 4 - xanthophyll blue-green - 1 - chlorophyll a yellow-green - 3 - chlorophyll b
What is the normal human body temperature at the Celsius temperature scale?
37ºC
In pea plants the Y allele encodes the yellow seed color and is dominant over the y allele that encodes the green seed color. The R allele encodes the round seed shape and is dominant over the r allele that encodes the wrinkled seed shape. What would be the phenotypic ratio of offspring from a YYRr x YyRr cross?
3:1 Yellow and round : Yellow and wrinkled seeds
If nondisjunction occurs during meiosis I, how many of the daughter cells will have an incorrect number of chromosomes?
4
A hematocrit of _______ would be about normal.
45%
If a female was a carrier for sex-linked color blindness, what percentage of her male children would also be color blind?
50%
Match the percentages to the correct type of leukocyte as we would see it in a healthy individual. *Note these are approximate values that vary with age, sex, body size, method of DIFF count, etc...
50%-70% - 3 - Neutrophils 25%-35% - 1 - Lymphocytes 4%-6% - 5 - Monocytes 1%-3% - 4 - Eosinophils <1% - 2 - Basophils
The results indicate that the organism prefers a pH of
7 The graph shows the most absorbance at pH 7 meaning that the most growth occurred in this tube.
At what pH will enzymes in human blood function best?
7.4
If you cross two heterozygous Yy pea plants, what proportion of the offspring will be the dominant color yellow?
75%
This image shows a Punnett's square that results from the crossing of two pea plants that are heterozygous for seed color. Yellow seeds is the dominant trait and green seeds is the recessive trait. Select each of the following statements are true about the phenotypic ratios for seed color in the offspring of this monohybrid cross.
75% Yellow seeds 25% Green seeds
Dark moths were released into either a clean forest (B) or a polluted forest (A). A sample of dark moths were recaptured every generation for five generations. The results can be seen in the graph below. How many moths were originally introduced into each forest?
750
If a sample of blood reacts with anti-A antibody and clumps, but not with anti-B antibody, this blood must be of type ______.
A
Based on a variety of experiments, it is known that the rate of photosynthesis is highest when wavelengths of light between 400 and 500 nm are used, and when wavelengths around 700 nm are used. What does this indicate about the relative importance of chlorophyll a and b in photosynthesis?
Absorption of light by chlorophyll a and b is essential for the process of photosynthesis.
If a sugar was allowed to ferment in a culture medium, what type of organisms would grow best?
Acidophiles Fermentation produces acid, resulting in lower pH values. This would favor the acidophiles.
You have successfully focused on an object with the 10x and 40x objective lenses. You have rotated the 100x objective lens into position but are unable to obtain a sharp image by rotating the fine focus adjustment knob. Which of the following is most likely to correct this problem?
Add a drop of immersion oil before rotating the 100x lens into position.
In lab, you are asked to perform an ELISA test to determine how closely the serum proteins of several species resemble those found in human serum. Put the steps of the ELISA test in order in which they are performed.
Add serum samples to individual sample wells. Add human serum to another well. Rinse after 60 minutes.1 Add antihuman antibodies to each well and wait 30 minutes. Rinse.2 Add detection antibodies to each well and wait 30 minutes. Rinse.3 Add detection dye and wait 15 minutes. Read results as intensity of color.4
Looking at your results from the molecular evidence lab, what do you think would have happened if you forgot to add the detection antibodies to all five of the wells?
All five wells would have stayed clear.
47.0 milligrams =
All of the answer choices are correct. 0.047 grams 4.7 centigrams 0.47 decigrams 0.00047 hectograms
Let's say you inoculate four agar plates, each containing a different antibiotic (A, B, C, and D), and you add a swab from a lesion taken from a patient. After incubating the plates, you observe that plate A has only a few colonies, while the others all have many colonies. How do you interpret the results?
Bacteria in the patient's sample are susceptible to antibiotic A but not B, C, and D
How does an antibiotic act as a selective agent in promoting bacterial resistance?
Bacteria with a random mutation that allows resistance to that antibiotic are able to survive exposure and reproduce, passing the resistance mutation on to subsequent generations of bacteria.
When testing for tonicity of red blood cells, why were you unable to read the lab manual through the tubes containing hypertonic or isotonic solution?
Because the cells in those solutions remained intact, causing the solutions to be opaque. Both the hypertonic and the isotonic do not destroy the red blood cells (RBCs), so the light is blocked by the RBC and the tube looks opaque.
Which of the following reagents is best suited for the detection of sugar?
Benedict's
Tube 3 did not have starch or amylase in it. Why did it show a positive reaction with Benedict's reagent?
Benedict's reagent reacts with maltose
________ reagent can be used to detect the presence of proteins or peptides.
Biuret
In the yeast fermentation experiment, what is being produced to cause the air bubble at the top of the tube to increase over time?
CO2
When trying to determine the rate of cellular respiration (an aerobic process), why is oxygen measured and not carbon dioxide?
CO2 is produced during both aerobic and anaerobic processes; we couldn't be sure cellular respiration was taking place.
When testing the temperature of catalase, why did the enzyme catalase work best at 37°C? (Select all that apply.)
Catalase works best at human body temperature. Normal human body temperature is 98.6°F, which equals 37°C.
Using your pH data from the pH enzyme lab, which statement(s) below are true? (Select all that apply.)
Catalase works best at pH7 Catalase works better in alkaline environments than acidic ones. The data from the lab shows that catalase reaction rate was the highest at pH7 and second highest at pH9. pH 9 is an alkaline environment. The acidic environments showed reduced reaction rates.
Match the following items to the blood test in which they are used Differential WBC count - 1 Wright's stain Hematocrit determination - 3 Centrifuge Hemoglobin concentration - 2 Hemoglobinometer Blood typing - 4 antisera
Differential WBC count - 1 Wright's stain Hematocrit determination - 3 Centrifuge Hemoglobin concentration - 2 Hemoglobinometer Blood typing - 4 antisera
A(n) ________ allele exerts its phenotypic effect in a heterozygote.
Dominant
How can root cells grow from shoot cells?
Each cell contains all the instructions for every part of the plant.
Why is DNA replication called semi-conservative?
Each daughter DNA molecule is composed of one parental strand and one new strand.
Why is enzyme concentration not used to measure the rate of enzyme-catalyzed reactions?
Enzymes are not consumed in reactions. Enzyme concentration does not change.
Which of the following are reasons for washing hands before and after lab activities? (Select all that apply)
Hands may be a source of contamination to the lab experiments. Hands may become contaminated with infectious bacteria during lab experiments. Hands may become stained during lab. Hands may be contaminated with irritating chemicals during experiments. -Hands may become contaminated with infectious microorganisms, hazardous chemicals, or stains. Hands might also be a source of contamination to the laboratory experiments.
A student set up respirometers to measure fermentation of two different carbohydrates by yeast. He measured the height of the bubble (in mm) in each respirometer every 5 minutes for 20 minutes. His data can be seen in the table below.
He forgot to add the yeast.
A(n) ________ genotype has two different alleles for a particular gene, such as "Tt".
Heterozygous
What would you like to learn more about after watching the video? Briefly explain the topic and why it is interesting to you.
I am intrigued by why does more diversity of a species means the environment is more stable. I am curious if that can apply to humans as well. Are people who live in an environment that is more diverse than those who do not. For instance, someone who lives around many trees and animals versus someone who lives in an apartment in New York.
In the video, which part was most interesting to you? Explain why it was interesting or how it related to your life.
I thought that it was interesting how he used a hula hoop to have an unbiased selection of sample size. I was also amazed by how many bugs he was able to get just by waving his net around. This relates to how I would maybe want to conduct an experiment if i was to do something similar on my own.
Which of the following best describes molecular motion?
Molecules move in random directions.
A phenotype that differs from the wild-type is referred to as a(n) ________.
Mutant
Indicate the correct order of steps as you bring an object into focus under high power.
Place slide on stage and secure with stage clips. Turn on the light and center the specimen over the light source. Focus specimen on scanning objective using coarse focus adjustment Rotate to low power objective, then use fine focus to sharpen the image Rotate high power lens into position. Readjust fine focus under high power to produce the sharpest image.
Bacteria from three different cultures were plated on agar plates containing ampicillin, an antibiotic. The results can be seen below. In which of the cultures were 100% of the bacteria susceptible to the antibiotic?
Plate C
Match the description of each WBC.
Polymorphonuclear (=nucleus twisted and segmented); slightly pinkish granular cytoplasm - 1 Neutrophil Large round nucleus takes most of the space in the cell; small cytoplasm ring around nucleus. - 5 Lymphocyte Large cell, twice as big as a red blood cell. Nucleus is "bean" or "C" shaped. - 2 Monocyte Cell full of red-pink staining granules; nucleus is bilobed (=two lobes). - 4 Eosinophil Cell is full of dark-purple staining granules; nucleus is bilobed (=two lobes). - 3 Basophil
You are working in a real lab setting, and when you test the catalase and water together you see a reaction. What does this tell you? (Select all that apply.)
Possible contaminant in the water causing a reaction. You must complete the experiment again to verify your results.
A student set up two test tubes containing Elodea plants and sodium bicarbonate and topped each of them with a volumeter. Tube A was wrapped in aluminum foil. Both tubes were placed in a test tube rack in front of a lamp containing a bright white bulb. The student obtained the following data from her experiment. Which of the following statements could explain this data?
The student did not turn the light on until after 10 minutes had already passed.
Which of the following statements about enzymes is FALSE?
The substrate binds to the enzyme with low specificity.
Briefly explain the topic in the video that was most confusing to you, why it was confusing, and how the information could be clarified.
The topic of this video is biodiversity. The man in the video is taking different random samples to see what varieties of plant and bug species he can find. He is trying to determine if there is a relationship between species and plants in a specific area. I am unsure of what the conclusion of his experiment was. why he is trying to find the relationship between the two, and why what he is doing will show that they are diverse. I am also confused by the type of graph he used. I think that it would have been better to use a bar graft.
What does it mean for a population to be in Hardy-Weinberg equilibrium?
There are no changes in gene frequencies from one generation to the next.
In the ELISA procedure, first a protein sample is immobilized to a plastic well. Then, the antibody to the protein of interest is added, incubated, and the excess is washed out. Next, the detection antibody (which binds to the primary antibody) is added, incubated, and the excess is washed out. The last step is to add the detection dye (which binds to the detection antibody) to the wells and allow it to incubate. What do you predict the result would look like if you forgot to add the detection antibody?
There would not be color present in any of the wells.
If water did not have a high heat capacity, what effects would it have on living organisms?
They would not be able to regulate their internal temperature.
major difference between red blood cells and Elodea cells, is that Elodea cells have a cell wall, which protects them from bursting. Group starts
True When a plant cell is placed in a hypotonic solution, the vacuole gains water and the plasma membrane pushed against the cell wall. The plant cell has a cell wall made from polysaccharides that prevents the cell from bursting.
A student set up an experiment to show the effect of light color on photosynthesis in Elodea plants. She filled three test tubes with distilled water and placed a piece of Elodea in each of the tubes. She added a drop of phenol red, which turns red in a basic solution and yellow in an acidic solution. She blew in each tube to add carbon dioxide, which caused the distilled water to become more acidic so the phenol red turned yellow. She exposed Tube A to white light, Tube B to green light, and Tube C was wrapped in aluminum foil. Which of the tubes should she expect to turn red the fastest?
Tube A
A student set up an experiment to show that carbon dioxide is consumed by Elodea plants during photosynthesis. She filled two test tubes with distilled water and placed a piece of Elodea in each of the tubes. She added a drop of phenol red, which turns red in a basic solution and yellow in an acidic solution. She blew in each tube to add carbon dioxide, which caused the distilled water to become more acidic so the phenol red turned yellow. She wrapped Tube A in aluminum foil and left Tube B exposed to the light. After 15 minutes, what should she expect to observe?
Tube A will be yellow and Tube B will be red
A human female with only one X chromosome is said to have a condition called
Turner syndrome.
Match each structure with its definition.
Two copies of duplicated chromosomes - 3 - Sister chromatids Two copies of a given chromosome pair - 2 - Homologous chromosomes The region of close association that holds two copies of duplicated chromosomes together - 1 - Centromere
Tim has an accident and needs a fast blood transfusion. Tim's blood type is "B". The hospital ran out of type B blood, but they have AB type, A type, and O type blood. Which type would Tim receive as it will provide the least issues for him?
Type O blood
Which of the following represent important safety procedures for microbiology students? (Select all that apply)
Wash your hands before and after laboratory procedures. Disinfect your lab bench at the beginning and end of the lab period. Take extra care around the flame of a Bunsen burner by tying up hair and keeping it from combustibles.
Which of the following correctly summarize the overall process of photosynthesis? (Check all that apply)
Water is absorbed by plant roots and combines with carbon dioxide in the leaves in the presence of sunlight to produce glucose and oxygen gas. CO2 + 2H2O + hv → (CH2O) + H2O + O2 . 6CO2 + 12 H2O + hv → C6H12O6 + 6O2 + 6 H2O.
When testing osmosis by measuring thistle tube height, what is the first step in the procedure?
apply membranes to the thistle tubes The membrane must be added to the thistle tube before adding any liquids to the thistle tube or beaker to mimic the action of a selectively permeable membrane.
Enzymes (Select all that apply)
are specific for their substrates. act as catalysts. have a special shape that controls their function. control the speed of reactions.
Laboratory instruments are sterilized prior to reuse by __________.
autoclaving (steam autoclave) It is customary to use the autoclave to sterilize infectious waste prior to disposal. While there are other means to sterilize this waste, the steam autoclave is the most practical.
Pond water can contain many types of organisms. Which of the following are you most likely to find in a pond water sample? Please select all that apply.
bacteria algae rotifers protozoa
An antacid is a(n)
base.
In the metric system, gram, meter, and liter are _____ units.
basic
In humans, if a non-disjunction event led to an individual with a genotype of XO, they would
be female because they do not have a Y chromosome.
In humans, if a non-disjunction event led to an individual with a genotype of XXY, they would
be male because they have a Y chromosome.
Why do scientists put so much effort into documenting their experiment and analysis?
because other researchers must be able to repeat the experiment in order to check the results
A disinfectant is used on your work surface:
before the beginning of lab procedures, after all work is complete, after any spill of live microorganisms. All of the answer choices are correct. The lab bench is disinfected prior to and at the end of each lab exercise. It is also important to use appropriate disinfection in the case of a culture spill.
What is the function of saliva?
begin carbohydrate digestion
What color is the daughter strand in the image?
blue
When something appears blue, it is absorbing all colors except
blue
Select the letter that matches the person correctly holding the microscope.
c one hand on neck one on base
Salivary amylase digests
carbohydrates
What cell structures and pigments are involved in photosynthesis? (Check all that apply).
carotenoids chlorophyll B chlorophyll A thylakoids fluid-filled stroma chloroplasts
Select each substance that is necessary to have a reaction.
catalase hydrogen peroxide
In order to determine the hematocrit, blood is placed in a
centrifuge
Goggles or appropriate safety glasses protect the eyes from (Select all that apply)
chemical splashes UV exposure when using UV radiation in the laboratory Goggles protect they eyes from chemical splashes, aerosols, and UV exposure. They don't protect the eyes from fumes or hot plate/Bunsen burner burns.
The primary photosynthetic pigment is
chlorophyll
Which part of the microscope will be used first to adjust the focus when starting with the lowest power lens?
coarse focus
Which properties of water contribute to the formation of the meniscus? Select all that apply.
cohesion adhesion Water molecule stick together (cohesion) because of the hydrogen bonds between water molecules. Water molecules are attracted (adhesion) to other material like the sides of the glass beaker. These two forces create the C-shaped curve/meniscus.
The ability of molecules to stick to each other is termed
cohesion.
Relative time of divergence from a common ancestor can be estimated by
comparing the degree of difference in protein structure.
Fur color in mice is affected by a gene with two alleles. The B allele causes dark brown fur and is completely dominant over the b allele that causes light brown fur. What is the fur color of a mouse with the genotype, Bb?
dark brown fur
Which of the following factors would increase the rate of diffusion? (Select all that apply)
decreased molecular size larger concentration gradient thinner media
Human catalase has an optimum temperature of 37oC. Increasing the temperature by 30 degrees above the optimum range will (Select all that apply)
denature the enzyme. cause an abrupt decrease in the rate of activity.
Ice floats on liquid water due to the property of
density.
When utilizing the scientific method, there are two types of variables. They are
dependent and independent.
What was the purpose of this experiment?
determine the most effective way to stimulate root growth in dogwoods
In the following figure, which cell exhibits the condition of plant cells that have been placed in an isotonic environment?
figure a Plant cells exposed to an isotonic solution will have decreased turgor pressure, as the vacuole inside the plant cell neither loses nor gains water because the solution concentrations are equal.
The enzyme responsible for the polymerization of nucleotides during transcription is
RNA polymerase.
E. coli bacteria were spread on both agar plates and incubated for 24 hours. What does this image tell you about the bacteria?
The bacteria were susceptible to streptomycin.
In the following figure, which cell exhibits the condition of plant cells that have been placed in a hypertonic environment?
figure c In the Tonicity in Elodea cells activity, the hypertonic 10% NaCl solution produced the shrunken Elodea cells and the hypotonic distilled water solution produced the swollen Elodea cells. Cells exposed to a hypertonic solution will cause the plasma membrane to pull away from the cell wall as the vacuole inside the plant cell loses water.
The fine adjustment knob on the microscope
fine-tunes the focus.
The term used to describe reproductive success is
fitness
Frequencies of alleles in a population occasionally change due to random changes. This process is called
genetic drift.
Which organism demonstrated successful homeostasis?
genetically modified corn
In the soybean experiment, the _____ used more oxygen and the ___ produced more ATP.
germinating seeds; germinating seeds
What anaerobic pathway in cellular respiration generates ATP from the breakdown of glucose?
glycolysis
In the metric system, the base unit of weight is the
gram In the metric system, gram is the base unit for weight, meter is the base unit for length, and liter is the base unit for a liquid.
Of the visible light spectrum, the rate of photosynthesis is worst under
green light.
Complementary base pairing is key to the genetic code. In a DNA molecule, the nitrogenous base cytosine pairs with
guanine
In order for natural selection to occur, organisms must (select all that apply)
have variation that can be passed from one generation to the next. have differential reproductive success. have adaptations to their environment.
The amount of energy required to turn a liquid into a gas is termed
heat of evaporation.
When only one copy of an allele is present in a diploid organism the condition is referred to as
hemizygous
In simple diffusion, molecules move from an area of ____ concentration to an area of ____ concentration.
high; low
The purpose of this video was to
highlight examples of the characteristics of life.
The protein responsible for coiling of the DNA molecule in eukaryotes is called
histone
Human cells have two copies of every chromosome. These pairs of the same chromosome are called ________ chromosomes.
homologous
When comparing two species, the presence of which type of structures indicates descent through modification from a common ancestor?
homologous
Human cells contain two copies of every chromosome, one from each parent. These two copies of the same chromosome are called
homologous chromosomes.
When comparing two species, which type of body structure indicates evolutionary relatedness?
homologous structures
Drag and drop the labels to identify the bones of the human arm.
humerus-1 radius-2 ulna-3 carpals-4 phalanges-5
What substance in the stomach causes its low pH?
hydrochloric acid
The unique properties of water are due to
hydrogen bonding.
The figure below reflects how animal and plant cells would respond in a(n) _______ environment.
hypertonic Since water is moving out of the animal cell and out of the plant cell in this image, they must be in a hypertonic environment with a high solute and low water concentration. This causes the water inside the cells to move outward into the solution.
Match the action to the appropriate phase of the scientific method
hypothesis - 3 formulate a hypothesis and create a strategy experiment - 2 carry out the strategy, collect measurements analysis - 4 draw graphs, evaluate the hypothesis report - 1 document results The scientific method starts with a hypothesis and an idea of how to test that hypothesis. During the experiment, you could carry out the formed strategy and collect measurements/data. In analysis, data is examined, and graphs can be used for a visual representation of the findings. Documenting the results would occur when you report your findings.
Which of the following reagents is best suited for the detection of starch?
iodine
Assume that you have an unknown solution in a test tube. When you add phenol red to the test tube, it appears pale pink. It takes 30 drops of hydrochloric acid (HCl) for the phenol red to turn yellow. Based on your experience in the Antacids as Buffers simulation, this is an indication that the solution in the tube
is a buffer.
When a person requires intravenous administration of fluids which type of you expect to most commonly use?
isotonic
Detergent is used in the DNA isolation process because
it facilitates homogenization.
An image of chromosomes arranged in pairs by size and shape is called a
karyotype
While mutation rates are not constant, DNA molecules may in theory act as a molecular "clock" because
known mutation rates for specific genes can estimate time of divergence from a common ancestor.
When performing a serum ELISA procedure, the sample wells are first coated with
known serum antigen(s).
Which of the following should be worn at ALL times in the lab? (Select all that apply)
lab coat closed-toed shoes A lab coat and closed-toe shoes should be worn at all times. It may be advisable to where protective goggles, a face mask, and gloves in some instances. Instructions regarding personal protective equipment for each lab activity will be provided by your instructor.
select all of the following that are true statements about fermentation.
lactate may be produced ethanol may be produced the reactions happen in the cytoplasm CO2 may be produced
Select all of the following that are products of lactic acid fermentation.
lactic acid carbon dioxide ATP
Photosynthesis takes place in the plant's
leaves and green stems.
Gel electrophoresis can be used to separate molecules by (Select all that apply)
length size charge
Which classes of macromolecules have a significant role in energy storage? (Select all that apply)
lipids carbohydrates
The lenses of a brightfield microscope are responsible for the _____ of the object you are viewing.
magnification
In the pillbug experiment, an important part of the experimental strategy was to
make observations at regular intervals. In order to have enough data to graph and draw conclusions, it is important that you take several measurements at regular intervals throughout the experiment.
An adaptation
makes a species more suited for its environment.
In gel electrophoresis, what is the agarose used for?
making the gel
Which of the following units is the metric basic unit of length?
meter
In the length unit exercise, what tool did you use to measure the circles?
metric ruler The ruler was a metric ruler with millimeter and centimeter markings.
Which prefix means 1/1000 or 0.001?
milli
What are the building blocks of complex carbohydrates?
monosaccharides
Which of the following is the source of new, novel alleles in a population?
mutation
Which of the following mechanisms of change in gene frequencies is responsible for the antibiotic resistance of E. coli in this experiment?
natural selection
Environmental selection of organisms most fit to reproduce is
natural selection.
The image shows a Benedict's test to determine the presences of reducing sugars. Is it positive or negative?
negative
The image shows a Biuret test to determine the presences of protein. Is it positive or negative?
negative
Which white blood cell has the greatest nuclear variations?
neutrophil
The organism in the video experiment would be classified as a
neutrophile The organism grew best at a pH of 7 so it would be classified as a neutrophile.
In which circumstance is food and/or beverage allowed in the laboratory?
never Food and beverages are NEVER allowed in the laboratory.
Air is a solution of gases. It is composed of 1% water vapor, 0.04% carbon dioxide, 21% oxygen, and 78% nitrogen. Which of the gases is the solvent?
nitrogen
Occasionally, chromosomes fail to separate during meiosis, leading to a condition in which the diploid number is not normal. This phenomenon is called
nondisjunction
A patient's hemoglobin content is determined to be 17 g/100ml. That is _____.
normal for a man, but high for a woman
The sequence of __________ in nucleic acids encodes a specific order of amino acids for making a protein.
nucleotides
The lens on the microscope that is primarily responsible for the magnification of the specimen is the _____ lens.
objective
The arrows are pointing to the
ocular lenses.
Which objective lens provides the highest total magnification?
oil immersion
Select all of the possible products of starch digestion by amylase.
oligosaccharides, maltose,
Gametes contain ______ copy/copies of each gene.
one
In humans, having dimples in the cheeks is a dominant trait. If a child has dimples but only one of her parents does, what are the genotypes of her parents?
one parent must be dd; the other parent could be either Dd or DD
Fermentation in yeast can occur without
oxygen
Which factor can change enough within the digestive system to alter the activity of an enzyme?
pH
Select all of the factors that influence an enzyme's activity.
pH temperature concentration of enzyme concentration of substrate
How does pH negatively affect the metabolism of microorganisms?
pH changes can denature enzymes pH changes can change the charges on amino acids in proteins and result in denaturation and loss of activity.
What is the variable in these tubes?
pH levels Each tube represents TSB with a different pH but with the same organism growing for the same period of time.
The "P" in P generation refers to
parental
Looking at your data collected from the gel electrophoresis, which patient do you think has the least ability to resist illness?
patient 1 (DNA sample 1)
A ________ is a tree-like chart that shows a family history for a particular trait across several generations.
pedigree
What is shown in this picture?
pedigree
The ________ of an organism is the physical appearance resulting from the expression of the genes present.
phenotype
Which of the following is not a reaction that cells use to get energy from nutrients?
photosynthesisCorrect
Molecules that absorb light energy are called
pigments
According to the results of the pillbug experiment,
pillbugs tend to prefer cornstarch over sand. If you look at your data you will see given the 12 minutes to move, all the pillbugs moved into the cornstarch chamber when given the choice between cornstarch and sand. When given just sand they moved equally between the two chambers.
When graphing your data, it is important to
place the dependent variable on the Y-axis.
When graphing your data, it is important that you
place the independent variable on the X-axis.
Suppose you have the speed on the x-axis and braking distance on the y-axis. Which graph would confirm the hypothesis "Braking distance is proportional to speed"?
points on a straight line through (0,0) progressing upward and to the right
Starch is a
polysaccharide
Starch is a(n)
polysaccharide
The image shows a paper test for lipids. Is it positive or negative?
positive
The image shows an iodine test for starch. Is it positive or negative?
positive
Which dye would you predict to move the fastest (and thus go furthest in a given time period) through agar?
potassium permanganate (mw = 158 g/mol)
Which of the following a great source of carbohydrates?
potato
Which of the following is the purpose of cellular respiration?
production of ATP
Select all of the types of molecules cells are built with.
protein carbohydrate lipid
Select all of the following that are formed elements in blood.
red blood cells white blood cells platelets
Which of the following steps are part of a thorough hand washing protocol? (Select all that apply)
removal of bracelets, watches, and rings lathering with soap, rubbing hands together for at least 20 seconds using a brush and wooden stick, clean well under finger nails When washing hands any jewelry or watches should be removed first. Soap should be applied to wet hands and turned into a lather while rubbing hands together for at least 20 seconds. If you have a brush or wooden stick near, cleaning under the finger nails should also occur.
Select all of the following that are characteristics of a scientific result.
reproducible systematic
A buffer can
resist changes in pH by binding with hydrogen and hydroxyl ions.
Translation begins when mRNA becomes associated with a(n)
ribosome
The objective lenses of the compound light microscope are attached to the
rotating nosepiece.
Based on your procedure from the pH enzyme lab, how can you accurately measure how pH alone affects an enzyme's ability to function?
same amounts of enzymes and different pH values If you change two variables (amount of enzyme and pH values) at the same time, you cannot accurately measure how each one affects the reaction rate independently.
In the pillbug experiment, the substance used as the control was
sand
Which objective lens provides the least total magnification?
scan
The three major steps of digestive function include all of the following, except
secretion
Since the cell membrane allows some molecules to pass through it and will not allow others, it can be described as
selectively permeable.
A membrane allows glucose through but not sucrose and galactose. What type of membrane is this?
semipermeable
A membrane allows water through but will not allow any solutes to pass. What type of membrane is this?
semipermeable
The serum ELISA test is based on interaction between
serum antigens and specific antibodies.
Traits that are carried on the X chromosome are said to be
sex-linked.
Where should glass slides, pipettes, and capillary tubes be disposed?
sharps container Each of these items pose a hazard for puncturing or cutting the skin and should be disposed of in a sharps container.
A change in a mRNA nucleotide sequence from UUU to UUC results in a
silent mutation.
In dialysis, the cleansing wastes from the blood is achieved by
simple diffusion across a semi-permeable membrane.
In the Antacids as Buffers simulation, the mortar and pestle were used to grind the antacids
so they would dissolve more easily.
Which treatment was least effective?
soaking in water for 24 hours
Types of natural selection include (select all that apply)
stabilizing selection directional selection disruptive selection.
Amylase is an enzyme that cuts ________ into smaller molecules.
starch
An unknown liquid sample is tested for chemical composition. You receive the following results: iodine test = purple/black; biuret test = purple; Benedict's test = blue; and paper lipid test = clear. Which of the following are present in this sample? (Select all that apply)
starch protein
The positive control for the Iodine test was the
starch solution.
Before you begin a scientific experiment, you should (Select all that apply)
state a hypothesis. decide on a strategy. To start an experiment you must have a hypothesis and a strategy. During the experiment you will record data collected and after you would report the results.
Which piece of equipment is routinely used for the decontamination of infectious laboratory waste?
steam autoclave Infectious laboratory waste is routinely decontaminated by use of a steam autoclave.
All three factors affecting image quality can be controlled by manipulating the microscope.
t
An individual with blood type O lacks both RBC antigens A and B.
t
Blood is a biohazard that requires special safety precautions.
t
Changing the pH of an enzyme catalyzed reaction can alter the rate of product formation.
t
Enzymes increase the reaction rate of a specific reaction.
t
Temperature, pH, and ionic concentrations play an important role in the proper functioning of enzymes.
t
The enzymatic reaction of amylase starts the chemical digestion of starch into sugars.
t
The fittest organisms in a species are the ones that are most likely to reproduce.
t
The formation of a green color after heating with Benedict's reagent indicates that a sample contains simple sugars.
t
The shape of an enzyme determines its function.
t
Water is composed of one atom of oxygen and two atoms of hydrogen.
t
Which of the following tears and cuts food?
teeth
_________ can change the active site of an enzyme and alter its function.
temperature and pH
During transcription, RNA polymerase uses the nucleotide sequence of the ________ to synthesize mRNA.
template strand of DNA
Two solutions are made by mixing sugar and enough water to make a 1 liter solution. One contains 5% sugar and the other contains 10% sugar. Which solution contains more water?
the 5% sugar solution
All of the following are required for the Calvin cycle except
H2O.
The oxygen utilized in cellular respiration finally shows up as
H2O.
E. coli bacteria was spread on both agar plates and incubated for 24 hours. If you wanted to grow up a large quantity of streptomycin resistant E. coli, what would you do next?
Pick a colony of bacteria from the streptomycin positive plate and grow it on a streptomycin positive plate.
How does mixing hydrogen peroxide and water test the reactivity of catalase?
It shows that hydrogen peroxide is not the chemical causing the reaction.
Water freezes at _____ and boils at _____ temperature. (Select all that apply.)
0 degrees Celsius; 212 degrees Fahrenheit 32 degrees Fahrenheit; 100 degrees Celsius Using the metric system, water freezes at 0ºC and boils at 100ºC. Using the American system, water freezes at 32ºF and boils at 212ºF.
How many pounds are in 1 gram?
0.0022
In a population, 25% of individuals exhibit albinism which is a lack of production of the pigment melanin. It is caused by two recessive allele (q2). What is the frequency of the recessive allele (g) in this population?
0.50
Assume you drink 250mL of soda out of a 1 liter soda bottle. How many liters are left?
0.75 liters
What is the freezing point of water on the Celsius temperature scale?
0ºC
Select the unit of weight that is heaviest.
1 kilogram
Please match each measurement with its equivalent answer.
1 millimeter- 2 - 0.001 meter = 1000 millimeters - 1 - 1 meter = 15 millimeters - 5 - 0.015 meters = 1 centimeter - 4 - 0.01 meter = 0.000515 kilometers - 3 - 0.515 meters = Centi is hundredth from the base, milli is thousandth from the base, gram is the base, kilo is thousand from the base. 1 meter = 1000 millimeters, 1 meter x 1000 = 1000 millimeters (going from base to smaller unit of measurement, multiple) 0.015 meters = 15 millimeters, 0.015 meter x 1000 = 15 millimeters (going from base to smaller unit of measurement, multiple) 0.001 meters = 1 millimeter, 0.001 meters x 1000 = 1 millimeter (going from base to smaller unit of measurement, multiple) 0.01 mete = 1 centimeter, 0.01 meter x 100 = 1 centimeter (going from base to smaller unit of measurement, multiple) 0.515 meters = 0.000515 kilometers, 0.515 meters/1000 = 0.000515 kilometers (going from base to a larger unit of measurement, divide)
How long should you wait before removing adult flies from the breeding tubes?
1 week
A man and a woman have three children, all males. What is the probability that their next child will be a girl?
1/2
Achondroplasia is a common form of dwarfism caused by autosomal dominant mutation in the fibroblast growth factor receptor 3 (Fgfr3) gene. If a person with achondroplasia (Aa) married and had children with a person of normal height, what is the probability that both their first child and second child would have achondroplasia?
1/4
In the pillbug experiment, how many pillbugs did you need to use to get good information for the experiment?
10
How many centigrams are there in a gram?
100
How many centimeters are there in a meter?
100
If a specimen was being viewed using a 100x objective and 10x oculars, what would be the total magnification?
1000x
The temperature outside is 40 degrees Celsius. What is this in degrees Fahrenheit?
104 degrees Fahrenheit To convert Fahrenheit to Celsius, subtract 32 and then divide by 1.8. To convert Celsius to Fahrenheit, multiply by 1.8 and then add 32. For example 40ºC x 1.8+32 = 104ºF.
During the fourth generation, 27% of the dark moths were captured from clean forest B. What percentage of moths were recaptured from polluted forest A during the fourth generation?
140%
When predicting the phenotypic ratio of a crossing between two heterozygous corn plants (PpSs), the ratio was shown to be 9:3:3:1. What would the phenotypic ratio be if we crossed two homozygous corn plants, with one homozygous dominant for both color and texture (PPSS) and the other homozygous recessive for both traits (ppss)?
1:0:0:0
In humans the recessive allele "a" results in the lack of the production of the skin pigment melanin. People who are homozygous recessive lack pigment and have white skin, pink eyes, and white hair. This phenotype is referred to as albinism. The normal allele for the gene in the pigment production pathway is "A". What phenotypic ratio of offspring is predicted by a cross between a man who is heterozygous (Aa) and an albino woman?
1:1 Albino: Normal pigment
Which of the following is absolutely required for the production of ATP?
ADP and Pi
Effect of pH on Microbial Growth Read the overview and complete the interactivities that follow. Many factors have an influence on the growth of microbes, including temperature, oxygen availability, osmotic pressure, and pH. In this exercise, you will be investigating the optimum pH value for growth of a particular bacterium. Based on its optimum, an organism can be classified as an acidophile, neutrophile or alkaliphile. Most bacteria are neutrophiles, but most yeast and fungi are acidophiles.
An acidophile would likely grow best at which of the following pH values? 14 A value of 0-6 on the pH scale represents levels of acidity. Therefore, a pH of 4 would likely favor the growth of an acidophile.
Place the following steps of the hand washing procedure in the correct order.
Apply soap.2 Dry hands thoroughly and use a towel to turn off the faucet.5 Thoroughly wet hands in running water.1 Rinse thoroughly in running water.4 Lather for at least 20 seconds by rubbing hands together, paying attention to the back of hands, nails, and between fingers.3 Wet hands first, apply soap, lather for at least 20 seconds, rinse hands, dry hands, and then use the towel to turn the water off.
Why is it recommended that hands be wet prior to adding soap? (Select all that apply)
Applying soap to wet hands will enable it to go into solution and produce more lather. Soap applied to dry hands may irritate the skin. Hands should be wet prior to adding soap so that soap will go into solution and produce more lather. Also, applying soap to dry skin may irritate the skin.
Which of the following represents a reactant or input for the light reaction of photosynthesis?
H2O
Why does DNA flow toward the positive side of the gel chamber?
DNA has a negative charge and is attracted by the positive side.
Which of the following describes DNA within a eukaryotic cell? (Select all that apply)
DNA is surrounded by two separate phospholipid membranes within the cell. DNA is packaged around proteins within the nucleus. The phosphate group of the nucleotides within DNA have a negative charge.
The purpose of the Antacids as Buffers simulation was to determine the amount of stomach acid it would take to degrade the mucous lining in your stomach and cause an ulcer.
False
All buffers have the same capacity to neutralize acid, regardless of the kind or amount of buffering chemicals they are composed of.
False As you noted in the antacid experiment, different buffering chemicals can have different buffering capacities.
Buffers always act to lower the pH of solutions.
False Buffers act to neutralize the pH of solutions.
After testing tonicity in the lab, the items that have been contaminated with blood can be disposed of in the trash can.
False Items contaminated with blood should be disposed of in the biohazard container, not the regular trash can in order to adhere to lab safety protocols.
2.2 pounds is equal to 10 kilograms.
False Since one gram equals 0.0022 pounds, 2.2 pounds/ 0.0022 = 1000 grams. Convert 1000 g to kilograms = 1000 /1000 = 1 kilogram
Blood cells are protected from bursting in a hypotonic solution because of their rigid cell wall.
False Plant cells have cell walls that protect plants cells from bursting, animal cells do not.
Beverages are allowed in the laboratory as long as the containers are covered.
False Food and beverages are never allowed in the laboratory.
_____ fruit flies have the genotype XX.
Female
After focusing on an object with the low power objective lens, you are trying to bring it into focus under the 40x objective lens, but the field of view is very dark. Which of the following may remedy this problem?
Increase the light intensity.
Match the names of the microscope parts in column A with the descriptions in column B. Place the letter of your choice in the space provided.
Increases or decreases the light intensity - Iris diaphram Platform that supports a microscope slide - Stage Concentrates light onto the specimen - Condenser Causes stage (or objective lens) to move upward or downward - Adjustment knob After light passes through the specimen, it next enters this lens system - Objective lens system
Changing the pH will have the following effects on a catalase-controlled reaction:
Increasing or decreasing the pH above or below the optimum level will decrease the activity.
Even though a population in true Hardy-Weinberg equilibrium cannot exist, how can using the equation be useful?
It can be used to detect changes in gene frequencies in a population over time.
Which of the following best describes the mechanism of action of the antibiotic streptomycin?
It disrupts protein synthesis in nonresistant bacteria.
Which is incorrect about fermentation?
It generates oxygen.
Select all of the following that are required of a scientific result.
It has been tested using the scientific method. It must be open to revision in the light of new data.
What is TNF alpha? (Select all that apply)
It is a protein that helps the body fight infectious diseases. It is a protein that helps the body resist some types of cancer.
Vibrio cholerae is the bacterium responsible for cholera, a GI tract infection. Normally, it takes the ingestion of over one million bacterial cells to cause infection, but the consumption of antacids signficantly lowers this number. What does this tell you about the likely classification of V. cholerae in terms of pH preference?
It is likely an alkaliphile. Antacids increase the pH of the GI tract when taken to offset acidity. Therefore, since the environment becomes more basic, V. cholerae, an alkaliphile, flourishes.
Which of the following statements about chlorophyll is correct?
It reflects light in the green light spectrum.
Which of the following occurs with enzymes as you increase the temperature from 80 degrees F to 90 degrees F?
It will bind substrate more frequently.
Jacob had just finished his lab work and went to the sink to wash his hands. He removed his watch, and added liquid soap to his hands. He then turned on the water and began to rub his hands together, lathering for 20 seconds and cleaning fronts and backs of hands, fingernails, and between his fingers. He then rinsed his hands in running water, dried his hands with paper towels, and used an additional paper towel to turn off the faucet. Which statement is correct?
Jacob should have wet his hands in running water before applying the soap.
Identify the correct statements about lab coats. (Select all that apply)
Lab coats provide some protection against contamination with infectious microorganisms. Lab coats provide some protection against exposure to corrosive chemicals. Lab coats provide some protection against contamination with infectious microorganisms and exposure to corrosive chemicals. Lab coats should be decontaminated BEFORE they leave the lab.
Effect of pH on Microbial Growth Read the overview and complete the interactivities that follow. Many factors have an influence on the growth of microbes, including temperature, oxygen availability, osmotic pressure, and pH. In this exercise, you will be investigating the optimum pH value for growth of a particular bacterium. Based on its optimum, an organism can be classified as an acidophile, neutrophile or alkaliphile. Most bacteria are neutrophiles, but most yeast and fungi are acidophiles.
Many bacteria that cause urinary tract infections must be able to withstand the conversion of urea to ammonia in the environment. Therefore, they must be at least tolerant of ________ conditions. alkaline The production of ammonia increases the pH, making the environment in the urinary tract more alkaline. Some bacteria are tolerant of this pH rise and can therefore cause UTIs.
How do the properties of water make it well suited to sustain life on Earth?
My answer:Because of water's ability to maintain temperatures it keeps the world from overheating. Water itself keeps the world cool but it also keeps those who consume it cool. If you drink a tall glass of water before you go outside on a hot day you are probably going to maintain a better temperature than if you were to go outside dehydrated. This is because the water you drank before you went outside is more resistant to the heat you are being exposed to and takes more time to warm up while also keeping you cool. Because water molecules cling together through hydrogen bonds, it is able to stay liquid across most of Earth's temperatures rather than just a gas (water vapor) or solid (ice). This also allows water to exist as a liquid in living cells. In the liquid form, water can act as a solvent to help transport substances and participate in chemical reactions. Because water is the main component of a living organism, they are able to maintain a relatively stable internal temperature due to water's high heat capacity. For organisms in hot environments, water evaporating from their skin provides cooling. The cohesive and adhesive ability of water allows it to naturally move through vessels in living organisms such as blood vessels and xylem in plants. If the solid state of water (ice) was more dense than liquid water, ice would sink to the bottom and lakes and the oceans would freeze solid, not allowing life to exist during cold seasons.
All of the following are the end products of glycolysis except
NAD+.
If you add sucrose to catalase when testing for reactivity, do you expect to see a reaction?
No, because catalase is specific to hydrogen peroxide.
Which of the following liquids can be safety pipetted by mouth? (Select all that apply)
None of the answer choices are correct. You should never pipette anything by mouth.
Each of the following steps are necessary in preparing and observing a wet mount. Place the steps in the correct order.
Obtain a clean slide and cover slip. Using a transfer pipette, obtain a drop of specimen and place onto the center of the slide. Carefully place the cover slip over the drop of specimen. Observe preparation under the 10X objective lens. Observe preparation under the 40X objective lens.
One gram is equal to 0.0022 pounds.
One gram equals 0.0022 pounds.
Chambers A and B are placed next to each other, but are separated by a film similar to a cell membrane. Chamber A contains 80% carbon dioxide and Chamber B contains 20% carbon dioxide. Which of the following will occur?
Some carbon dioxide will move from chamber A to chamber B.
In pea plants, smooth (S) peas are dominant over wrinkled (s) peas in the single gene controlling pea texture. A plant with smooth peas is crossed with a plant with wrinkled peas. Of the progeny, 252 are smooth and 247 are wrinkled. What are the genotypes of the parent plants?
Ss and ss
If 10 Typica moth and 90 Carbonaria moth were released into a polluted forest what would happen over several generations?
The Typica moth population would decline. The Carbonaria moth population would have a reproductive advantage in the polluted forest. The recessive allele frequency would decrease each generation.
Some students consume large amounts of caffeinated drinks to help them stay alert when studying. You notice that many who engage in this practice seem to do poorly on exams. Suppose you want to investigate the relationship between caffeine consumption and exam performance. Which of the following statements would be an appropriate hypothesis?
Students who consume large amounts of caffeine while studying have lower exam scores than students that consume less caffeine while studying. A hypothesis is a tentative explanation for a phenomenon that can be tested and then supported or falsified based upon the results. To test the hypothesis, you would compare the exam scores of students who drink large amounts of caffeine while studying to those who do not. If the students who consume more caffeine have significantly lower scores, then your hypothesis is supported. Otherwise, the hypothesis is falsified. The statement that one should avoid consuming too much caffeine while studying is a recommendation, not a hypothesis. The statement that caffeine increases alertness but also increases anxiety would have to be tested more directly rather than looking just at exam scores. The statement that many students consume large amounts of caffeine caffeine while studying to try to improve their exam scores is an observation that could contribute to a hypothesis about why students are choosing to drink caffeine during study sessions, but it doesn't directly state a way to investigate the relationship between caffeine consumption and exam performance. Too much caffeine is harmful to your health is a conclusion that has been reached by some scientific studies; it is not, however, a hypothesis that is appropriate to this experimental design.
Diffusion continues to occur until there is an equal concentration of particles on both sides of a semi-permeable membrane.
T
Diffusion is the movement of a molecule from an area of higher concentration to an area of lower concentration.
T
Ethanol cannot be added to the test tube too quickly because it will break up the DNA precipitate.
T
Imagine that you wish to compare two different diets that will be fed to tadpoles raised in a lab. One diet is a meat-based fish food, and the other is the traditional diet of boiled lettuce. You want to see if the meat-based diet will be associated with an increase in the average weight of the tadpoles. In your experiment you keep all other factors, such as tadpole density per pan, temperature, pH, and the amount of food the same. The only difference between your control and experimental groups is the type of food the tadpoles receive. Which is a good hypothesis for this tadpole experiment?
Tadpoles will be larger if fed a meat-based diet. A good hypothesis is one that makes a prediction based on information known and predicts the behavior based off an independent (and testable) variable (there should only be one). The independent variable here is the type of food.
In the Movement of Water across a Selectively Permeable Membrane lab, you were given an alternate hypothesis: "As the concentration of the solutes (corn syrup) increased, osmosis will decrease'. If this alternate hypothesis was correct, what would you have seen happen in your experiment?
The 10% corn syrup solution would have seen the greatest increase in thistle volume. If higher solute concentrations caused decreased osmosis, then the 30% corn syrup solution would have shown decreased water movement into the thistle compared to the 10% corn syrup solution.
Which of the following apply to the development of streptomycin resistance in E. coli?
The E. coli population has genetic variation. The selective agent is streptomycin. The mutation resulting in streptomycin resistance is random.
When Elodea leaves were placed in 10% NaCl, what was the result?
The cell membrane shrank away from the cell wall because the solution was hypertonic. In the tonicity in Elodea cells activity, the hypertonic 10% NaCl solution produced the shrunken Elodea cells and the hypotonic distilled water solution produced the swollen Elodea cells.
When you receive fluid in the hospital, it is often 0.9% saline solution. What would happen if the nurse used distilled water instead?
The distilled water solution would be hypotonic to your blood cells, so they would gain water, swell, and possibly burst. 0.9% saline solution is isotonic compared to your red blood cells (RBCs) and distilled water is hypotonic to your RBCs. The distilled water solution would cause water to move down its concentration gradient from the solution across the selectively permeable membrane into the cell cytoplasm, which would cause the cell to swell and possibly burst.
What topic did you learn most about after watching this video? Briefly explain the topic and your new understanding.
The less variety of plant species in an area will result in a smaller variety of bugs. Reducing biodiversity. Meaning that if you want to promote biodiversity it is important to have a wide variety of plant specices in a designated area.
Dark moths were released into either a clean forest (B) or a polluted forest (A). A sample of dark moths were recaptured every generation for five generations. The results can be seen in the graph below. Which of the following statements is correct?
The moth population in forest A are experiencing reproductive success.
What is the advantage of using a wet mount?
The motility of a specimen can be viewed under a microscope. The specimen can be viewed as living cells.
How is enzyme activity influenced by pH?
The pH can alter how the substrate fits in the active site.
Effect of pH on Microbial Growth Read the overview and complete the interactivities that follow. Many factors have an influence on the growth of microbes, including temperature, oxygen availability, osmotic pressure, and pH. In this exercise, you will be investigating the optimum pH value for growth of a particular bacterium. Based on its optimum, an organism can be classified as an acidophile, neutrophile or alkaliphile. Most bacteria are neutrophiles, but most yeast and fungi are acidophiles.
The spectrophotometer measures the transmittance of growth. More light transmittance would mean ________ growth in the sample tube. less If more light can transmit through the sample, it is less cloudy (turbid) with bacterial growth.
If we had done this same experiment with Saccharomyces (a yeast), how would the graph have appeared differently after plotting the spectrophotometer readings?
The peak would have been more to the left. Yeast are usually acidophiles, meaning that their growth would peak in the pH 4-6 range (on the left of the graph).
In pea plants there is a dominant allele (A) for green pods and a recessive allele (a) for yellow pods. Suppose a heterozygous plant is crossed with a plant that has yellow pods. Complete the sentences about this monohybrid cross with the correct terms.
The phenotype of the heterozygous plant is green pods. The genotype of the heterozygous plant is Aa. The genotype of the plant with yellow pods is aa. The genotype of the gametes produced by the heterozygous plant is 50% A and 50% a. The genotype of the gametes produced by the plant with yellow pods is 100% a. The expected frequency of F₁ plants with yellow pods is 50%. The expected frequency of F₁ plants with the genotype AA is 0%. (The heterozygous plant would have the genotype Aa and the phenotype of green. The yellow pods would have a genotype of aa. The gamete produced by the heterozygous plant would have genotypes of 50%A and 50%a, while the gametes produced by the yellow pod would be 100%a. The expected outcome would be that 50% of the gametes produced by a combining of these two plants would be 50% yellow and 0% would have AA genotype.)
Select all of the following reasons why the rooting powder stimulated root growth.
The powder sent chemical signals to initiate cell division. It sent chemical signals promoting cells to differentiate.
What would you predict would happen to the fermentation rate if you used yeast suspension that had not been swirled/mixed each time before it was dispensed into test tubes?
The reaction rate would be very low.
Resistant and nonresistant E. coli bacteria samples were spread on the agar plates below and incubated for 24 hours. Select the true statements from the list below.
The resistant E. coli strain grows on streptomycin negative plates. The nonresistant E. coli strain grows on streptomycin negative plates. The resistant E. coli strain grows on streptomycin positive plates.
While testing an unknown solution a student adds Benedict's reagent and watches as the contents of the test tube turn green. The student then added amylase and heats the test tube. This causes the contents to turn red. Which of the following conclusions could the student make?
The solution has both simple sugars and starch.
If you wanted to test whether or not a particular pain reliever was effective in the general population, you would need to design an experiment with an experimental group and a control group. What should be the only difference between these two groups?
Treatment: The experimental group should get the pain reliever, and the control group should get a placebo The control group is the group that received the independent variable. A placebo won't do anything to relieve pain, thus the group taking the placebo would be the control group because their pain levels would be unchanged.
Effect of pH on Microbial Growth Read the overview and complete the interactivities that follow. Many factors have an influence on the growth of microbes, including temperature, oxygen availability, osmotic pressure, and pH. In this exercise, you will be investigating the optimum pH value for growth of a particular bacterium. Based on its optimum, an organism can be classified as an acidophile, neutrophile or alkaliphile. Most bacteria are neutrophiles, but most yeast and fungi are acidophiles.
What class of organisms is likely to inhabit the human body? neutrophiles Human body pH is near 7, and therefore most bacteria that inhabit the body are neutrophiles.
Colorblindness in humans is encoded by the X-linked recessive allele "b". To demonstrate your knowledge of how to set up a Punnett Square to represent a mating between a XBXb female and a XBY male, indicate which of the following choices could be placed into the box indicated by the arrow.
Y
Do you think the experiment and information presented in the video was accurate? Explain why or why not.
Yes, it makes sense. The more diverse an area is the more plants and animals there are contributing to the environment. Biodiversity allows things like pollination, honey, food is provided for animals and insects that will eventually decompose and provide nutrients for plants from the soil. Everything works cohesively.
When preparing a wet mount specimen for viewing, the specimen should be covered with
a coverslip.
The pH of a solution is
a measure of the concentration of hydrogen ions it contains.
Natural selection occurs when
a new genetic variation occurs that allows individuals to have a reproductive and survival advantage.
During the time that the particles are diffusing into the cell
a point is eventually reached where equal numbers are passing into and out of the cell.
The ability of molecules to stick to other surfaces is termed
adhesion
The cellular respiration pathway that occurs in the mitochondria is
aerobic
Which type of process requires oxygen as a substrate?
aerobic
The pH can affect the activity of an enzyme-controlled reaction by (Select all that apply)
affecting hydrogen bonding changing the shape of the enzymes active site altering the interaction between the substrate and the enzyme active site changing the ionic state of either the enzyme or the substrate. pH can affect the hydrogen bonds between neighboring amino acids that create the folded shape of the protein (enzyme) as well alter the shape of the enzyme's active site. The ionic changes that can be caused by a non-optimal pH environment can affect the shape of the enzyme or the shape of the substrate, which could affect the ability of the formation of the substrate-enzyme complex.
The biuret test would indicate a positive result for proteins in which of the following solutions?
albumin solution
In the absence of oxygen, what anaerobic pathways can occur after glycolysis? (Check all that apply.)
alcohol Fermentation lactate Fermentation
The higher the pH the more ________ the environment.
alkaline Solutions with a pH above 7 are alkaline. The higher the pH, the more alkaline the environment.
An alternative version of a gene that determines a specific trait is called a(n) ________.
allele
What problem is most likely the case when a person has a high count of eosinophils?
allergic reaction
Mosquitos need certain _____ _______ from blood to help develop their eggs.
amino acids
What are the building blocks of proteins?
amino acids
The environment of the stomach causes the activity of _____ to be inactivated.
amylase
Which of the following digests carbohydrates?
amylase
Egg coloration that acts as camouflage is an example of
an adaptation.
A male athlete has a hematocrit of 55% prior to a competition. That indicates _____.
an endurance trained male in the normal range
Imagine that you wish to compare two different diets that will be fed to tadpoles raised in a lab. One diet is a meat-based fish food, and the other is the traditional diet of boiled lettuce. You want to see if the meat-based diet will be associated with an increase in the average weight of the tadpoles. In your experiment you keep all other factors, such as tadpole density per pan, temperature, pH, and the amount of food the same. The only difference between your control and experimental groups is the type of food the tadpoles receive. What is the independent variable for the tadpole diet experiment?
diet The independent variable is the group that is being examined.
Small lipid soluble molecules would move through the plasma membrane by
diffusion
A mating between individuals that traces two genes of interest is called a ______ cross.
dihybrid
Which of the following items can be washed in the sink after use in the laboratory? (Select all that apply)
dissection tools glassware that was not used with hazardous chemicals dissection trays Glassware that was not used with hazardous chemicals, dissection tools, dissection trays, and staining trays can all be washed in the sink in the laboratory after use. Agar plates and broth culture tubes pose an infectious hazard and are not washed in the sink. Culture plates are discarded in the biohazard bag. Culture tubes are autoclaved prior to discarding the contents, washing, and reusing. Inoculating loops are generally not washed, but are sterilized in the Bunsen burner flame or in a bench top incinerator.
Water moved across a membrane, into the thistle tube
down its concentration gradient. The water moved across the selectively permeable membrane down its concentration gradient from an area of high water concentration (more water/less solute = beaker) to an area of low water concentration (less water/more solute = thistle).
The probability of a heads - tails - heads sequence in three successive coin tosses is one in ________.
eight
What is the process of breaking down large fat globules into smaller fat globules?
emulsification
Where are the A, B, and Rh antigens located?
erythrocyte
Change over time describes
evolution
Capillary tubes must be spun in a centrifuge to perform a hemoglobin test.
f
Heavier (larger) particles move faster than lighter (smaller) particles at the same temperature.
f
Lipids mix well with water.
f
Microevolution results in the formation of a new species.
f
The active site is located on the substrate.
f
The rate of photosynthesis is much greater in the green than red light spectrum.
f
The solid state of most substances is less dense than the liquid state.
f
Water and hydrogen peroxide react to form oxygen.
f
