In Drosophila, the X-linked recessive mutation vermillion (v) causes bright red eyes, in contrast to the brick-red eyes caused by the wild-type allele. A separate autosomal recessive mutation, brown (bw), causes flies to have brown eyes. Flies with both mutations have no eye pigmentation and are white-eyed. Determine the F1 and F2 phenotypic ratios for each sex from the following crosses:
(a) vermillion females X brown males
(b) wild-type females X white-eyed males
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How did the forebrain, midbrain, and hindbrain change over the course of evolution? Be specific. You must tell me how the three-part brain evolved into a 5-part brain (which is a hint in and of itself). What are two functions of each?
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2. SELECT AN INFECTIOUS AGENT AND CREATE THE CHAIN OF INFECTION AS PER THE MODEL. IDENTIFY WHAT STEPS CAN BE TAKEN TO BREAK THAT CHAIN. (note – you cannot select E. Coli but you can get creative!).
Let's examine the chain of infection as it applies to this situation.
INFECTIOUS AGENT
RESERVOIR
PORTAL OF EXIT
MODE OF TRANSMISSION
PORTAL OF ENTRY
SUSCEPTIBLE HOST
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You mate a male from a true-breeding strain of dwarf mice to a female from a true-breeding normal-sized strain. The F1 mice are all normal in size. What would the phenotypes of the F1 and F2 mice be in the reciprocal of the above cross if the dwarf character is caused by a mitochondrial genome defect?
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1. Describe the stages of C. elegans development, and indicate how you would differentiate between these stages?
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Glycolysis requires four different phosphotransferase reactions. Identify the phosphoryl donor, acceptor, and nucleotide end-product for each. The choices for each box are the same and they are 1,3-Bisphosphoglycerate, ADP, ATP, Fructose-6-phosphate, Glucose, Phosphoenolpyruvate.
| enzyme | phosphoryl donor | phosphoryl acceptor | nucleotide end product |
| Hexokinase | |||
| Phosphofructokinase | |||
| Phosphoglycerate kinase | |||
| Pyruvate kinase |
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In: Biology
Cytosolic pyruvate is the end product of glycolysis. Its fate depends on the metabolic status of the cell. If there is plenty of oxygen, the aerobic pathway dominates. If oxygen is insufficient, the anaerobic pathway dominates. Associate each of the following characteristics with either the aerobic or anaerobic fate of pyruvate.
| Catalyzed by lactate dehydrogenase | |
| Catalyzed by pyruvate dehydrogenase complex | |
| Oxidizes NADH | |
| Oxidizes pyruvate | |
| Produces acetyl CoA | |
| Produces lactate | |
| Recycles NADH to NAD+ | |
| Redirects glucose oxidation to the mitochondrion | |
| Reduces NAD+ | |
| Reduces pyruvate |
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A.)There are four important steps in a Gram stain. List the specific stains/chemicals used in each step, and the color of both Gram positive and Gram negative bacteria after each step.
B.)Describe 2 reasons why heat fixing a specimen before viewing under a microscope is important.
C.)Describe how the design of the swan - necked flasks in Pasteur's classic experiment helped disprove spontaneous generation. What were the results of the experiment? How did it counter the "vital force" argument believed by many scientists.
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In: Biology
What is the importance of relay signaling in development?
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An energy pyramid illustrates a great loss of energy at each level of a food web. Each level of the pyramid has only 10% of the energy at the level below it. If the producer level has 10,000 calories for the food we, how much energy is available of each of the next three levels?
In your opinion, how do you think problems like pollution and deforestation are linked with population growth?
How can the growth of a population be slowed by its own numbers?
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| 16. A human nephron A. is one of the two kidneys B. is the functional excretory unit C. is about the size of your fist D. all of the above |
17. The proximal convoluted tubule A. is lined by microvilli B. excrete salt ions of sodium and potassium C. secretes unneeded proteins D. absorbs organic acids |
18. Urine entering the collecting duct A. will have salt added as it descends B. will have urea added as it descends C. will have water added as it descends D. none of the above |
19. The multiplier effect A. increases the salt concentration of the cortex B. decreases the salt concentration of the urine C. is due to the absorption of salt into the urine D. none of the above |
20. Alcohol and caffeine increase urine volume by
A. decreasing blood pressure and increasing ADH production
B. increasing blood pressure and decreasing ADH production
C. increasing blood pressure and increasing ADH production
D. decreasing blood pressure and decreasing ADH production
In: Biology
A strain of E. coli carries a mutation that completely inactivates the enzyme encoded in the gene. Several revertants, mutants of the mutant with partly or fully restored activity, were selected, and the amino acid sequence of the enzyme was determined. The only differences found were at position 10 in the polypeptide chain.
Revertant 1 had Thr.
Revertant 2 had Glu.
Revertant 3 had Met.
Revertant 4 had Arg.
Assume that the initial mutation itself, as well as each revertant, resulted from a single nucleotide substitution.
a. What amino acid is present at position 10 in the mutant protein?
b. What codon in the mRNA would encode this amino acid?
Please provide explanations and not just correct answers.
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In: Biology