What would happen to the activity of cdc2 kinase if the cdc25 phosphatase were mutated so that it was permanently inactivated?
In: Biology
22. You are studying a toxin that prevents RAS, a GTPase from hydrolyzing GTP. You find that this toxin increase the amount of cell growth. Please explain this finding.
23. You find that some cells have mutations that permanently deactivate Raf in this pathway. Please state whether you agree or the Ras-affecting drug from the previous question will increase the amount of cell growth in the inactive Raf mutants.
Agree or Disagree?
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1. Which toxicants do you consider to be the greatest threat to human health (or, possibly, existence)?
2. Why is glutathione status so important in the patient with high exposures to toxicants? How can you use the testing studied in this course to evaluate it?
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During passage through which of the following is fluid significantly concentrated in a mammal kidney?
A. Collecting duct when ADH production is very low
B. Descending limb of the loop of Henle
C. Proximal convoluted tubule
D. Ascending limb of the loop of Henle
In: Biology
2. a. If you represent the allele frequencies as f(T)=p and f(t)=q, what does the Hardy-Weinberg Equilibrium Model predict the genotype frequencies will be in the rodent population in the next generation (show the calculations)?
b. What are the assumptions of the Hardy-Weinberg Equilibrium Model?
c. What does the model predict about the genotype and allele frequencies at generations 10, 100, 1000? (Note: This is where the “Equilibrium” comes from)
d. So, the H-W Eq. Model is a model of no evolution. It predicts that the genetic composition of a population should remain constant over time IF no forces of evolution (the Assumptions in b. above) are acting in the population. Briefly, what is the use of this model of no evolution in studying evolution at a genetic locus?
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Explain how the digestive, circulatory, lymphatic, endocrine, nervous and excretory systems in mammals work together to deliver oxygen, calories, biological molecules, and nutrients while removing metabolic waste and regulating water balance and blood pressure.
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Why is the effect of genetic drift relatively "strong" (i.e. can potentially cause larger change in allele frequency from generation to generation) in small populations and relatively "weak" in large populations? Include the following terms in your answer: gene pool, gametes, sampling error.
In: Biology
In a population of rats, the homozygous genotype BB produces black coat color, Bb produces gray coat color, and bb produces white coat color. When the population is surveyed, you find that there are 60 black rats and 40 gray rats, and no rats with white coats.
A. What are the gene frequencies for the B and b alleles in this population?
B. If this rat population randomly mates, what are the expected ratios of black, gray, and white rats in the next generation? (Assume Hardy-Weinberg equilibrium applies.)
In: Biology
Briefly describe Somatic Hypermutation and Affinity Maturation processes. Include in your answer:
a) what each of these processes is,
b) what cells and genes are directly affected by these processes,
c) where these processes occur in the body
d) what is the significance of these processes to the immune response?
In: Biology
Complement pathways _
Explain how classical pathway, Alternative pathway, lectin pathway
and terminal pathway are activated to destroy bacterial cells?
In: Biology
You are seeing a patient whose insulin receptors cannot bind to insulin. Which of the following would you expect? select two
a. HEr cells have too many glucose transporters at the cell membrane
b. This person cant lower her blood glucos levels
c. This perosn cant raise her blood glucose levels
d.her cells dont have enough glucose transporters at the cell membrane
In: Biology
Write a one-page mini-proposal for a research project that would test your hypothesis.
Introduce the objective of your research. Use scientific species names and specific names of communities/habitats/biomes, focus on ecological interactions, and include scholarly references*. Describe the experiment you propose to conduct. Describe your controls and the kind of measurements you would take, with scholarly references*. Explain how your results could refute or confirm your hypothesis. Using scholarly references*, propose which ecological problem(s) your project could potentially contribute to solving? (e.g.: conservation, sustainability)
In: Biology
1. What is secreted from both natural killer (NK) cells and cytotoxic T (TC) cells from holes in the cell membranes leading to the eventual destruction of the target?
a) Lysomes
b) Perforin
c) Complement
d) Bacteriocin
2. What is the name for a mutagen that insets itself between 2 base pairs so that an extra base is added during DNA replication? Ethidium bromide DNA is an example.
In: Biology
You and your hypothetical lab partner each develop an experimental plan to test this hypothesis. The two experimental plans are presented below. Evaluate each plan for its pros and cons in the experimental design using the bullet points below. Both experimental plans have some good elements and areas that could be improved.
Experiment A) Mature 2 inch sections (sprigs) of Elodea will be used to measure oxygen production under different light conditions. 5 sprigs will be tested. One will be kept in the dark (no light). The others will be exposed to a light filtered with cellophane. One sprig’s light will be filtered through clear cellophane to receive all wavelengths of light, and the other sprigs’ light will be filtered through red, blue, and green cellophane, respectively. The no-light plant will be kept in a dark cabinet, while the other plants will be together on a counter. Each plant sprig will be placed in equal sized upside-down test tubes in 100ml of tap water so that oxygen bubbles produced by the plant will be trapped at the top of the test tube. A ruler will be used to measure the length of the oxygen pocket collected at the top of the test tube. The experiment will continue until one sprig produces 5 cm of oxygen in the tube.
Experiment B) 3 cm sections (sprigs) of Elodea of various ages will be used to measure oxygen production under different light conditions. 15 sprigs will be divided into 3 groups of 5 sprigs each. One group will receive natural sunlight, one group will be exposed to a blue light bulb under a box to block natural light, and the final group will be exposed to a red light bulb under a similar box to block natural light. Each group of plant sprigs will be trapped under a clear plastic funnel that is covered by an upside-down test tube to collect oxygen bubbles produced by all the sprigs in the group. All groups will be in 100ml of water of the same temperature and pH. The experiment will continue for 24 hours, and then the volume of oxygen gas produced will be measured by multiplying the length of the oxygen pocket by the circle described by the test tube, ?r2. The average volume produced by all groups will be graphed and compared to determine which condition produced the most total volume of oxygen.
Consider the following questions to evaluate experimental plans A and B (DO NOT ANSWER THESE QESTIONS)
What is the independent variable suggested by the hypothesis? Do both plans test the independent variable equally well?
What is the dependent variable in each experiment? Which experiment’s dependent variable best matches the prediction in the hypothesis?
What are the experimental and control groups for each experiment? Which experiment gives the best opportunity to assess the effect of the independent variable?
How does each experiment account for standardized variables? Which experiment do you think is the better controlled experiment?
How is sample size addressed in each experiment? Which would you find to be more convincing?
Does either experiment describe any statistical analyses to be performed on the data?
ANSWER THIS QUESTION: BELOW
Considering your analysis of each of the questions above,write an improved experimental design to test the hypothesis “If blue light is more effective at promoting photosynthesis, then more oxygen gas (O2) will be produced when plants are exposed to blue-filtered light compared to other wavelengths.”You may use elements of the above experiments
In: Biology
Regarding T cell and antigen presenting cell (APC) interactions, name a pair of proteins that mediate the initial interaction between these cells. In your answer, indicate which protein is expressed by the T cell and which protein is expressed by the APC.
Answer Part b i and ii.
The interaction between these proteins becomes stabilized in some cases, thereby prolonging the cell-cell contact.
i. What event triggers the interaction between these proteins to become stabilized?
ii. How does the interaction between these proteins become stabilized i.e. what’s the mechanism?
This is how the question was asked... im not sure how he wants it exactly but anything will help.
In: Biology