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Human Biology

ANS fibers

Which ANS fibers release acetylcholine? Which release norepinephrine?

Sympathetic activation

Indicate the results of sympathetic activation of the following structures: sweat glands, eye pupils, adrenal medulla, heart, lungs, liver, blood vessels of vigorously working skeletal muscles, blood vessels of digestive viscera, salivary glands. Which of the effects would be reversed by parasympathetic activity?

Cerebrospinal Fluid

(a) How is cerebrospinal fluid formed and drained? Describe its pathway within and around the brain. (b) What happens if CSF is not drained properly? Why is this consequence more harmful in adults?

Determining Neuronal Activity

Since at any moment a neuron is likely to have thousands of neurons releasing neurotransmitters at its surface, how is neuronal activity (to fire or not to fire) determined?


Please answer the following: (a) Explain the difference between an EPSP and an IPSP. (b) What specifically determines whether an EPSP or IPSP will be generated at the postsynaptic membrane?

Action Potential Generation

This job describes the events that must occur to generate an action potential (AP). It then relates the sequence of changes in permeability to changes in the ion channels and explains why the AP is an all-or-none phenomenon.

Integumentary homeostasis

You go to the beach to swim on an extremely hot, sunny summer afternoon. This job describes two ways in which your integumentary system acts to preserve homeostasis during your outing.

Neurobiology questions

1. Two types of GABA receptors have been identified. The GABA(a) receptor is an ion channel permeable to CL-; and the GABA(b) receptor is a G-protein-couple receptor (activates a second messenger cascadein the postsynaptic cell) which causes K+ selective channels to open. What effect would the activation of GABA(b) receptors hav

Volume & Concentration Problem is asssessed.

I have 100mls of an antibiotic stock solution at a concentration of 6mg/ml. I would like a final volume of 10mls of the antibiotic at a concentration of 1.5mg/ml. How much of the stock solution do I need to obtain this?

Serial Dilutions are explained.

You are given a milk sample that Mr. Milkman claims contains 3.8 x 10^8 CFU/ml. He claims this is within the limit of acceptable CFU/ml for Grade A milk. Diagram a procedure he could use to determine the CFU/ml and information pertinent to proving or disproving Mr. Milkman's claim. Is the milk within the acceptable limit?

Auditory System

Consider two hearing-impaired persons. One is deaf in the left ear but has normal hearing in the right ear. The second cannot hear frequencies above 1 kHz in either ear, but has normal hearing in both ears for lower frequencies. What problems would these two persons have with such everyday auditory tasks as localizing sound in s

Dilution Series for Liquid Culture of Staphylococcus Aureus

If you had a liquid culture of Staphylococcus aureus and transferred 2ml to test tube "R", which contains 8ml of nutrient broth, what would be the final dilution (in simplest terms) of the culture in test tube "R"? From the culture in "R" make a 1:15 dilution in tube "S". What is the final dilution of the culture in tube "S"?

Dilution Series

I am looking for a detailed solution and explanation. I give you 10mls of an overnight culture of Micrococcus luteus at a concentration of 4.7 x 10^7 CFU/ml. Diagram a dilution series by using tubes containing 9ml nutrient broth (NB) and fixed-volume 1ml pipettes (won't measure any more or less than 1ml).

Dilution Series

Perform a 2-fold serial dilution using 4 tubes containing 1ml of NB each and a 20ml broth culture of Bacillus subtilis; use the same B. subtilis culture and perform a 2-fold serial dilution using 4 tubes containing 2ml of NB each; repeat in a similar fashion using 4 tubes containing 0.5ml each.

Dilution Series

I give you a very expensive strain of E. coli containing 10^12 CFU/ml and tell you that I need exactly 10ml of the same E. coli culture at a concentration of 10^4 CFU/ml (I don't want any excess culture). Using a dilution series, how would you get the correct concentration and volume of bacteria? Make this a realistic scenario.

Reproductive strategies, the human population, population growth

Identify the two most extreme types of reproductive strategies and make a distinction between the traits that would characterize these extremes. Give an example of an organism that illustrates each strategy. Identify the major problems anticipated with the increase in the human population in the 21st century and explain why i

Flow Chart to Represent the Organizational Relationships

Draw a flow chart to represent the organizational relationships between the following terms from the most inclusive to the least inclusive: ecosystem, population, species, community, and biosphere. Please provide a brief definition of each.

Define and Identify the Relationship with Stress

I started to answer these could you please help me ? C. Define and identify the relationship that the following have with stress: Epinephrine: A hormone secreted by the adrenal medulla. Epinephrine plays a central role in the short-term response to stress reaction. It is the physiological response to threatening excitemen

Protein and Elements in Solution

Can you please confirm my choices for the below question? 1. A denatured protein is one that a. Has lost its three dimensional structure. b. Has reverted to a carbohydrate. c. Lacks amino acids. d. Lacks covalent bonds. My choice is (D) 2. Ions and atoms of an element differ in the a. Number of electrons they posse


1. IS THIS SCIENCE? Promotional materials for a sports drink say that "water is not enough" for people who are exercising and that it's important to instead consume a liquid that contains flavoring, carbohydrates, potassium and sodium. Do you think that consuming a sports drink after exercise can help maintain homeotasis? E

Topic: Smoking( see full description)

Topic: Smoking The topic must relate to the human body and contain in the following: 1. Introduction stating issue/problem and opinion/stance on this issue. 2. Main body- history/background supporting documentation, opposing Opinions, pros/cons. 3. Summary 4. Bibliography (at le

Muscle biopsies and functions of the cytoskeleton

3. If muscle biopsies (sample of tissue) were taken from the legs of a world-class marathon runner and a typical couch potato, which would you expect to have higher density of mitochondria? Why? How would the density of mitochondria in a muscle biopsy from the biceps of a weight lifter compare with those of the runner and th

Provide solution

Consider the consequences if a large meteor were to impact with Earth. What characteristics would be essential for survival ? What types of characteristics would be detrimental? What would have to be preserved in order to establish a diversity of life? What are the implications on evolution? What is your predic

'What would the world be like if solid water (ice) was denser than liquid water?

One of the science fiction magazines is having a call for conference topics. You decide to submit the following topic: ''what would the world be like if solid water (ice) was denser than liquid water?" Create a brief synopsis and include a brief discussion on the following issues: how you think the world would be diffe

Role of fungi in forests

If all the fungi were removed from our Pacific Northwest Forests how would that change our forests? (brief but thorough)

Roles of energy in biology

1. Relate energy concepts to living things - 1 paragraph. 2. Why energy is not recycled in an environment ? 1 paragraph . 3. Why an ecosystem can only support a finite population of species. 1 paragraph. 4. Discuss human's excessive consumption of energy and its implications upon future generations

AXONS at a Distance

What is a 'target' and how does it exert an effect on axons at a distance? Can you give me examples of targets and the area of the cells that is targeted?

Serial dilution problem

You have decided to determine how many microbes are living on the lettuce in the salad bar at your favorite restaurant. You place 1 gram of lettuce and 99 mls of water in a blender and blend the mixture. This is sample A. You then transfer 1 ml of this dilution into to another that contains 9 mls of water. This becomes sampl

Circulatory and Lymphatic System

Lymphatic system 1. Bean shape lymphatic organs found along lymphatic vessels are called... a. lymph nodes b. medullary cords c. germinal centers d. cistema chili 2. In innate immunity a. each exposure is very specific b. previous exposure are remembered c. each exposure elicits approximately the same type of respon