describe how the structure of the cellular membrane allows it to do its function. in your answer include three functions and indicate which molecules contribute

How do regulatory enzymes, secondary messengers, and major hormones influence the process of lipolysis?

What other various methods does white adipose tissue exert influence on metabolic and pathophysiological processes?

Problem 1

You are doing a genetics experiment with the fruit fly. In the “P” generation, you cross two true-breeding flies. Thefemale parent is brown and wingless and the male parent is black with normal wings. All of the flies in theF1 generation are brown and have normal wings.

Assume the genes are not found on a sex chromosome. Indicate the body color alleles with B and b and thewing size alleles with N and n.

a) The genotypes of the flies in the P generation are: Female:_____BBnn_________ Male:___bbNN___

b) The genotype of the flies in the F1 generation is: __BbNn___________

c) You now take an F1 female and cross her to a true-breeding black, wingless male. This male’s genotype is:_____bbnn_________

d) When the flies in (b) and (c) are mated, you count 1600 offspring in the F2 generation. If the body color geneand wing type genes are not linked, how many flies of each phenotype would you expect? (Be sure to use a Punnett square for a dihybrid cross to show your work.)

Show your work:  

Expected flies:

   _0_: # of brown, winged flies (Genotype: __BbNn__)

__800__: # of black, winged flies (Genotype: ___Bbnn___) __800___: # of black, wingless flies (Genotype: ____bbNn___) __0_____: # of brown, wingless flies(Genotype: __bbNN___)

e) When you count the F2 generation, you actually get 85 brown, winged flies, 728 black, winged flies, 712 brown,wingless flies, and 75 black, wingless flies. These results indicate that the body color and wing size are linkedgenes.

·What are the phenotypes of the recombinant flies? (Hint: Refer back to the P generation flies in the first paragraph. Recombinant flies do not resemble the original P generation phenotypes.)

·Calculate the recombination frequency (%) between the linked genes for body color and wing size.

Problem 2

You cross a true-breeding yellow-bodied, smooth-winged female fly with a true-breeding red-bodied, crinkle-winged male. The red body phenotype is dominant to the yellow body phenotype and smooth wings are dominant to crinkled wings. Use B or b for body color alleles, and W or w for wing surface alleles.

a) What are the genotypes of the P generation flies?

b) What will be the genotype(s) and phenotype(s) of the F1 offspring?

c) You discover that the genes for body color and wing surface are linked. You perform a dihybrid test crossbetween the F1 flies from part (b) with a true-breeding yellow-bodied, crinkle-winged fly. Use the followingF2 results to determine the recombination frequency (%) between the body color and wing surface genes. (Remember that the recombinants are the ones that do not resemble the parental types from the P generation.)

You decide to turn your attention to a different gene, one that controls wing length. This gene has two alleles, "L orl" where long wings are dominant to short wings. Remember that the red body phenotype is dominant to the yellow body phenotype. You again mate two true-breeding flies:

P: red-bodied, short wing male X yellow-bodied, long wing female

F1: All red-bodied, long wing

d) You perform a test cross between the F1 flies above with true-breeding yellow-bodied, short-winged flies. You get the following F2 results. What is the recombination frequency (%) between the genes for body color and winglength?

e) Based on the information in (c) and (d), what are the two possible arrangements of these three genes: body color,wing surface and wing length? Draw two linkage maps to show the possible arrangements of these genes and the map distance between genes

an essay of 800 words about polar bears and extinction

n a 800 word essay describe the path followed by an amino acid from absorption to delivery to a cell. Compare this path with the one followed by a large fatty acid. Support your essay with scholarly resources.

Humans are bipedal, terrestrial omnivores. As a species, we are adapted to quite a range of habitats, from deserts to mountains and from rain forests to tundra. Ultimately, however, we are descended from early hominids who evolved in African plains, and our body systems tend to reflect this. Your job is to determine how humans might be adapted if they had evolved in an aquatic environment where they live entirely in the water and breathe through gills.

Consider the following:

• What would be required to extract oxygen and exchange CO₂ and how the circulatory would have to change to compensate? You are encouraged to look up other (non-human; can be non-mammalian) animals that share these habitats for ideas.
• What if humans had evolved and were adapted to live in very specific habitats? In other words, it would still look *basically* like a human but would have some important differences related to its circulatory and/or breathing systems.
• What would these systems of a human that adapted to a different environment look like, and why would it look like this?
• You should consider the following parts of the breathing and/or circulatory system in your answer: Heart – size, activity, Lungs - size, Breathing rate, Oxygen transport system, Blood - Red Blood Cells (count), hemoglobin, and plasma levels, anything else you think is important to the circulatory and breathing systems.

3. What are the major elements required for microbial growth, and how are they used by the cell?

explain the role of lipids in maintaining the structure of the cell membrane.

Describe the principles of In-frame cloning

Describe the movement of Na⁺ and K⁺ in each event.

Events:

• Resting membrane potential
• Depolarization (rising phase)
• Falling phase
• Hyperpolarization

A tumor cell with a mutation in Rb can divide in the absence of extracellular signals.

A. If the Rb mutation is responsible for the increased cell division, is it likely that Rb is always active or always inactive? Explain your reasoning.

B. Which of the following molecules would be likely to block division of these tumor cells? Select all that would block division in cells with this Rb mutation.

       a. An inhibitor of Ras GEF

   b. A MAPK inhibitor

       c. An inhibitor of the G1 checkpoint Cdk

   d. An inhibitor of E2F (transcription factor regulated by Rb)

   e. An inhibitor of DNA polymerase

C. Explain why the choice/one choice in part B would block division of cells expressing this Rb mutant.

D. Explain why one of the choices in part B that you did NOT select would NOT block cell division in cell expressing this Rb mutant.

1. Draw a picture of a cell located in the intestines for yourself and label the surfaces and draw the location of the different receptors found on the plasma membranes. Then explain in your own words to turn in all of the different carrier proteins involved in the reabsorbtion of sodium and glucose from the intestinal mucosa to the blood.
2. What is the functional significance of tight junctions? Reflect on the fact that this is the same system involved in the kidneys for the reuptake of sodium and glucose in the kidney tubules. Why is that important to consider?
3. Draw a picture of a parietal cell located in the stomach for yourself. What protein carriers are important in the production and secretion of HCl in the stomach. How is this process influenced by carbon dioxide transport on the erythrocyte plasma membrane?
4. What is the importance of solute concentration on the reuptake of water in animal and plant cells?
5. How do vacuoles work? What is the importance of V-class H+ ATP-ase pumps in the uptake of water?
6. Channel proteins are typically involved in the import of ions across the plasma membrane. What are the major characteristics of potassium leak channels?
7. What is the importance of the water of hydration in the importance of movement of ions, like potassium, through channel proteins?
8. How is the Na+/K+ ATP-ase critical in the re-establishment of the resting membrane potential across the plasma membrane of animal cells.
9. How do voltage-gated ion channels work in the venus fly trap.
10. In anatomy and physiology, we discussed how nerve signals travel to the cochlear nerve allowing us to hear. Using your knowledge of anatomy and the information provided on the power point slides provided to you explain the role of stress-activated channels in this process.
11. Cholera toxin, a pathogenic intestinal bacterium, causes an indirect reduction in the activity of the Na+/K+-ATPase in intestinal epithelial cells. This results in reduced uptake of small sugars and amino acids from the intestine, as well as severe diarrhea. How are these two problems (eg. reduced nutrient uptake and diarrhea) coupled to impaired Na+/K+- ATPase function?
12. Like animal cells, the plasma membrane of plant cells has a membrane potential and plant cells also use cation-based symport for nutrient uptake. However, plant cells do not have Na+/K+-ATPase in their plasma membranes. Explain, then, how they establish and maintain a membrane potential and how they co-import nutrients in the absence of the Na+/K+ pump. Also explain how plant cell volume is regulated in light of this major difference.