Experimental Design
Which gene is has a significantly different Cq value than the RPS5 gene in the developmental stage?
the RBP-AF gene
The drug 5-fluorouracil inhibits thymine production in eukaryotic cells. Which of the following cell cycle stages will be most directly affected by 5-fluorouracil?
a. The first growth phase (G1)
b. Synthesis of DNA phase (S)
c. Preparation for mitosis (G2)
d. Cytokinesis
b. Synthesis of DNA phase (S)
Picture Needed.
How would you set up the graph?
Bar graph because categories. Number of Mitochondria on y axis (with units included), and species on x axis. Each category (species) would have two bars. One bar for normal CO2 and another for elevated CO2, would need legend. Error bars would be needed.
What THREE things can denature a protein?
High temp, low pH, high pH
Picture Needed.
Calculate the Simpon's Diversity Index for the community.
Need to answer.
Picture Needed.
(b) Identify the dependent variable in the experiment.
- Dry mass of the plants, specifically the change in dry mass
Scientists have found that the existing populations of a certain species of amphibian are small in number, lacking in genetic diversity, and separated from each other by wide areas of dry land. Which of the following human actions is most likely to improve the long-term survival of the amphibians?
a. Cloning the largest individuals to counteract the effects of aggressive predation
b. Reducing the population size by one-fifth to decrease competition for limited resources
c. Constructing a dam and irrigation system to control flooding
d. Building ponds in the areas of dry land to promote interbreeding between the separated populations
d. Building ponds in the areas of dry land to promote interbreeding between the separated populations
The pyruvate dehydrogenase complex (PDC) catalyzes the conversion of pyruvate to acetyl-CoA, a substrate for the Krebs (citric acid) cycle. The rate of pyruvate conversion is greatly reduced in individuals with PDC deficiency, a rare disorder.
(a) Identify the cellular location where PDC is most active.
- Mitochondria OR
- Mitochondrial Matrix
Mitochondrial DNA
Picture Needed.
A moth's color is controlled by two alleles, G and g, at a single locus. G (gray) is dominant to g (white). A large population of moths was studied, and the frequency of the G allele in the population over time was documented, as shown in the figure below. In 1980 a random sample of 2,000 pupae was collected and moths were allowed to emerge. Assuming that the population was in Hardy-Weinberg equilibrium for the G locus, what percentage of moths in the natural population was white in 1962 ?
4%
A controlled experiment was conducted to analyze the effects of darkness and boiling on the photosynthetic rate of incubated chloroplast suspensions. The dye reduction technique was used. Each chloroplast suspension was mixed with DPIP, an electron acceptor that changes from blue to clear when it is reduced. Each sample was placed individually in a spectrophotometer and the percent transmittance was recorded. The three samples used were prepared as follows.
(b) Identify and explain the control or controls for this experiment.
one point each, 3 points possible
- sample 1 is control
- sample 1 is in the light and has permissive temperature/functional structures (membranes, proteins, enzymes all still work)
- control is the basis for comparison to treatment effects
- reliability of data (identical procedures, reagents, measurements, adequate sample size - must identify at least 2
In some species of bats, adult females regurgitate (bring up food from the stomach) to feed their young. In addition, adult bats regurgitate to feed other adults that have not recently eaten. The adults receiving the food may be unrelated bats who have previously participated in food sharing and are members of the same social group. Scientists claim that sharing among unrelated adult bats increases the fitness of the species.
Which of the following best supports the scientists’ claim?
a. Bats that do not find food over a 24-hour period may die, preventing their alleles from being passed on within the social group.
b. Bats that do not find food may adapt to eating other types of food, adding new alleles to the social group.
c. Food sharing reduces the number of unrelated animals that cluster in one area, thus increasing the genetic diversity in the social group.
d. Food sharing increases the number of unrelated animals that cluster in one area, thus decreasing competition for food among members of the social group.
a. Bats that do not find food over a 24-hour period may die, preventing their alleles from being passed on within the social group.
Thirty corn seedlings of equal size were randomly assigned to one of three treatment groups. At the beginning of the experiment, the plants in group I were dried and the mass was determined. The plants in group II were maintained in light for a week. The plants in group III were maintained in the dark for a week. All conditions, other than light, were the same for groups II and III. At the end of the week, the plants in groups II and III were dried and the mass was determined. The experimental results are provided in the table. Table shows plants grown in the light experienced a greater increase in mass.
(a) To explain the increase in mass of the light-grown plants, identify ONE inorganic source of new plant mass and connect it to the cellular process underlying the increase in mass.
- CO2 is the inorganic source of new plant mass
- CO2 is incorporated into carbohydrates during the calvin cycle of photosynthesis
Describe the monomer of a nucleic acid.
Nucleotide - has a sugar, phosphate, and base. Phosphate is negatively charged.
Elements it has = oxygen, carbon, hydrogen, and phosphorus.
Picture Needed.
An agricultural biologist was evaluating two newly developed varieties of wheat as potential crops. In an experiment, seedlings were germinated on moist paper towels at 20ºC for 48 hours. Oxygen consumption of the two-day-old seedlings was measured at different temperatures. The data are shown in the graph. Calculate the rates of oxygen consumption in mL/min for each variety of wheat at 7°C and at 17°C.
Variety A at 7oC: (0.5 – 0 mL)/(80 – 0 min) = 0.0062 mL/min
Variety A at 17oC: (3.2 – 0 mL)/(80 – 0 min) = 0.040 mL/min
Variety B at 7oC: (3.6 – 0 mL)/(80 – 0 min) = 0.045 mL/min
Variety B at 17oC: (5.2 – 0 mL)/(80 – 0 min) = 0.065 mL/min
Picture Needed
A researcher conducted an experiment to determine the ability of yeast to grow on media that differ in amino acid content. Yeast can grow as both haploid and diploid cells. The researcher tested two different haploid yeast strains (Mutant 1 and Mutant 2), each of which has a single recessive mutation, and a haploid wild-type strain. The resulting data are shown in Table 1.
(a) Identify the role of treatment I in the experiment.
- Positive control
- To test viability of all yeast strains
- Allows the researcher to be confident that changes in experimental outcome are due to differences in treatments
In dogs, one pair of alleles determines coat color (dark and albino). Another pair of alleles determines hair length (short and long). Thus, each gamete will contain one of the coat-color alleles, C or c and one of the hair-length alleles, B or b. In repeated crosses of a specific dark, short-haired dog with an albino, long-haired dog, all the offspring were dark with short hair. However, in subsequent crosses of a dark, short haired dog with a dark, long haired dog, the offspring were - 3 dark and short, 3 dark and long, 1 albino and short, and 1 albino and long. In the second cross between the dark, short haired dog and the dark, long haired dog, the genotype of the dark, short-haired parent is...
CcBb (heterozygous for both traits)
Increasing the efficiency of photosynthesis is one way to increase crop yield and help to feed human populations. One enzyme vital to the Calvin-Benson cycle of photosynthesis is Rubisco.
(a) The small subunit of Rubisco is made up of many monomers. Describe the general structure of one of these monomers, including the characteristic that would allow it to interact with a negatively charged monomer in a second Rubisco polypeptide.
What role does water serve in photosynthesis?
Replenishes the electrons for the electron transport chain. Oxygen is a bi-product and can be used for respiration (if diffused into the mitochondria).
Picture Needed.
Bacteria can be cultured in media with a carefully controlled nutrient composition. The graph above shows the growth of a bacterial population in a medium with limiting amounts of two nutrients, I and II.
(b) Using the data, calculate the growth rate in cells/(mL×hour) of the bacterial population between hours 2 and 4.
4,995
Caenorhabditis elegans is an approximately 1 mm long nematode (worm) that lives in the soil and eats bacteria such as Pseudomonas. Scientists have determined that when C. elegans is hunting for food, the worms have different patterns of movement that depend on the location and quality of the food source. Scientists hypothesized that C. elegans might be attracted to certain chemicals produced by Pseudomonas. They tested this hypothesis by placing 100 C. elegans in the center of each of a series of petri dishes containing a layer of agar over which the worms could move. A drop of a test chemical diluted in ethanol was placed at one edge of each dish and an equal-sized drop of ethanol was placed at the opposite edge of the dish. The scientists determined the number of worms to reach each spot over a period of time.
(c) State the null hypothesis.
The C. elegans will be distributed equally in the dishes, they will not be more attracted to the test chemical than the ethanol.
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Hydrogen peroxide is broken down by a catalyzed reaction. Students performed the reaction at different concentrations and measured the reaction rate by measuring how fast a leaf disk floated (the reaction produces oxygen gas, so as the reaction proceeds, the oxygen "pushes up" the leaf disks).
Why did the disks rise to the surface faster in the more concentrated hydrogen peroxide solutions?
The higher substrate concentrations in the more concentrated solutions speeded the reaction.
Picture Needed.
(a) Describe the transfer of energy that occurs in the reaction shown in Figure 1.
- Energy is released during the hydrolysis of ATP and then captured in the formation of a new bond between F6P and the phosphate to form FBP. OR
- Energy is transferred from the ATP molecule to the F6P molecule to form FBP.
Describe the differences between mitosis and meiosis.
Prophase 1 - chromosomes condense and nuclear envelope disappears. homologous chromosomes pair up and crossing over occurs.
Metaphase 1 - homologous chromosomes line up in center of the cell.
Anaphase 1 - homologous chromosomes separate.
Telophase 1 - nuclear envelopes reappear and cell starts to pinch into two.
Cytokinesis 1 - two new haploid cells are formed.
Prophase 2 - nuclear envelopes disappear, chromosomes reform. homologous chromosomes don't pair up and crossing over does not happen.
Metaphase 2 - chromosomes line up in center of the cell.
Anaphase 2 - sister chromatids separate.
Telophase 2 - nuclear envelopes reappear, cells start to pinch in.
Cytokinesis 2 - there are officially four new cells!
Picture Needed.
In a certain type of chicken, the allele for gray feathers is recessive to the allele for black feathers, and the allele for a spotted pattern is recessive to the allele for a solid pattern. Chickens that are heterozygous for both traits were crossed and the phenotypes for the offspring were recorded (Table 1).
To determine whether the data are consistent with the expectations for independent assortment, students performed a chi-square analysis.
Calculate the chi-square value and evaluate the null hypothesis.
Chi square is 0.95, the null hypothesis would fail to be rejected.