Pulley lab physical science lab
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how does the mechanical advantage of a pulley system change when increaIng the number of pulleys?
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BIO 120 Grossmont College Difussion & Osmosis Worksheet
Exercise 6 - DIFFUSION AND OSMOSISStudent Learning Outcomes
At the completion of this exercise you should:
(l) Be able ...
BIO 120 Grossmont College Difussion & Osmosis Worksheet
Exercise 6 - DIFFUSION AND OSMOSISStudent Learning Outcomes
At the completion of this exercise you should:
(l) Be able to define the terms diffusion and osmosis.
(2) Be able to list and discuss four mechanisms that cells use to move molecules across their plasma membranes.
(3) Be able to explain what Brownian motion tells us about atoms and molecules.
(4) Be able to explain the relationship between molecular weight and the rate of a molecule’s diffusion.(5) Be able to list the characteristics of molecules that can, and those that cannot, move passively across a cell’s plasma membrane.
(6) Be able to describe how the solute concentration, inside of a cell, affects the rate (speed) of osmosis.
(7) Be able to define the following terms: concentration gradient, selectively permeable membrane, hypertonic, hypotonic, isotonic, and homeostasis.Introduction
Virtually all life forms are composed of cells. The cell is called the fundamental unit of life because within it occur most of the biochemical life processes. One of the phenomena of life is that the chemical composition of a cell remains fairly constant, in spite of the fact that the cell continually uses substances from its external environment and at the same time discharges other substances into its environment: This state of chemical constancy in living systems is called homeostasis. This homeostasis, in addition to the fact that a cell's surroundings are always of relatively different chemical composition from its inside, leads us to hypothesize that there must be some very selective means of chemical exchange across a cell's plasma membrane. Today, we will investigate the processes of movement of some substances into and out of cells.
Question 1. Most "cells" do not appear to have an obvious "mouth" or other visible structures in their cell ("plasma") membranes. Suggest one other way in which materials might be able to pass through the cell's membrane:Replace this text with your answer.
Question 2. Cell biologists tell us that there are 4 basic mechanisms that cells use to get molecules across their membranes. You need to learn these 4 strategies. Go to your textbook, or other reference source, and define the following 4 mechanisms:
1.)Osmosis2.)Facilitated diffusion3.)Endocytosis and exocytosis4.)Active transport
Brownian Motion
Robert Brown made an interesting observation in 1827 that led to the principle that "all atoms and molecules" are in constant motion. Dr. Brown was a botanist and army surgeon who was looking at particles inside pollen grains when he noticed the "rapid oscillatory motion of microscopic particles." He later observed the same movement when looking at substances, like India Ink. India Ink is made of water and billions of suspended clumps of carbon atoms. Under high magnification, Brown observed that the clumps of carbon atoms were vibrating wildly in all directions. He hypothesized that moving water molecules, which cannot be seen, must be colliding with the clumps of carbon, forcing them to move. Further study has shown that Dr. Brown was correct and, today, we call this kind of observation "Brownian motion".
A physical scientist would tell you that particles (atoms and molecules) are moving because "they have heat energy (Kinetic energy)". If you ask what kinetic energy is, you will be told that it is "random molecular motion" which, of course, is a circular argument. The point here is that we really do not know the ultimate reason why all atoms and molecules on earth are moving, only that they are and that the more heat energy ("kinetic energy") atoms or molecules have, the faster they move.
You are about to make this observation under the compound microscope yourself. The proper way to carry the compound microscope will be demonstrated. Always use two hands. Make sure that the cord is not dangling to prevent a tripping hazard. One hand should be holding the base of the microscope, while the other should hold the arm of the microscope.
Before using the microscope, check for the condition the microscope was left in from the prior class.
Was the microscope placed back in its assigned compartment with the arm facing out toward you?Was the cord wrapped between the stage and objectives with the plug tucked inside the cord?Was the cord relatively untangled?Was the ocular lens clean? (If not, clean the dirty lens with the appropriate lens cleaner and lens paper (not a paper towel).Was the light turned off?Check that the Condenser is at its highest point, directly below the stage. There is a knob connected to the Condenser that allows it to be moved up and down.Was the mechanical stage centered so that the stage clips don’t hang over the edge of the stage?Was the scanning objective lens (4x) (not another objective) placed over the stage? If not, rotate the nose piece until the scanning objective is facing the stage. Was the stage lowered to the lowest setting possible position? If not, use the coarse focus knob to do so, not the fine focus knob.Were there any slides remaining on the stage? If so, remove the slide and notify your instructor. It is important that the slide is placed in the correct box, or it may get lost.If any of these conditions were problematic, please let your instructor know.
Procedure:
Plug in the cord and turn up the light intensity.to its maximum value and adjust the iris diaphragm to its most closed setting. As you proceed you can increase the light passing through the specimen by gradually opening the iris diaphragm.
Adjust the distance between the oculars: Without placing the prepared slide on the stage yet, look through the oculars. You are likely going to see two circles of white light. Do not try to focus your eyes on any one thing, as nothing is in focus yet. Slowly, move the two oculars together and/or further apart until the two circles of white light become one circle of light, the Field of View.
Lower the stage using the coarse focus knob, and make sure the (shortest) scanning objective is facing the stage, so that there is no chance of the slide scratching any objective lenses.
Prepare your wet mount slide. Wash and dry a glass slide. Place a small drop of India ink on a clean slide. Place a cover slip on the slide.
Coverslip: Carefully cover the preparation with a clean plastic coverslip as follows:
Place one edge of the coverslip near to the drop. The stain and water with which you mixed the cells will flow along the junction of the edge of the coverslip and the slide. Carefully lower the coverslip over the specimen keeping the edge of the coverslip in contact with the slide. In this way, the water will flow slowly and uniformly about the specimen and force out air bubbles from beneath the coverslip. (A few air bubbles are not a serious problem for your first slide.)
Excess fluid: If liquid spills out or may spill out from under the coverslip, gently blot the excess with a towel, so that it will not later drip onto the stage of the microscope. Before looking through the eyepiece (ocular), open the stage clip, and place the slide on the stage of the microscope beneath the objective, with the coverslip visible on the upper side. The stage clip should be holding the slide in place, not pressing the slide under it. Using the left and right/up and down stage knobs), center the object below the objective without looking through the oculars. Nothing is in focus yet.
Coarse adjustment with scanning lens: With the scanning lens in place, move the stage up to its highest point without looking through the oculars. Nothing is in focus yet.
Looking through the ocular with your right eye only (squint or cover your left eye), bring the specimen into focus by turning the coarse focus adjustment knob slowly until the specimen is generally in focus. Then turning the fine adjustment knob will bring the specimen into sharper focus.
Focus your left eye: Viewing the specimen with both eyes through both oculars, turn the left ocular diopter until the specimen is clear in both eyes.
Iris diaphragm: The light coming through the microscope may be either too bright or too dim. If the amount of light is not satisfactory, it can be adjusted by carefully regulating the size of the opening of the iris diaphragm by moving the lever beneath the stage. The iris diaphragm is part of the condenser which concentrates the light coming from the light source.
Adjusting on low and high power objectives - use fine adjustment knobs only: If you wish to view the specimen using higher magnification, center the specimen in the field, and carefully rotate the revolving nosepiece to bring the next higher power objective into place beneath the body tube. The specimen will no longer be in focus. In order to sharpen the image of the specimen, adjust the focus using only the fine focus adjustment knob. (Again, the light may have to be adjusted with the iris diaphragm.) Each time you move to the next higher power objective, be sure you center the specimen beforehand.
Examine the drop first under scanning, then low power, then under high power. Be sure you can see the individual particles of India ink.
Focus your attention on one particle (under high power) for several seconds. Look for a slight but vigorous movement of this particle, independent of the other particles. (Note: You may need to wait a few minutes. Then, if you see a mass "flowing" movement of all the particles in one direction like a small river, this is not Brownian motion. Wait for the flowing to subside, then carefully observe one particle.)
Question 3. Describe the Brownian motion in your own words:
Replace this text with your answer.
Question 4. Describe, in your own words, how this observation indicates that all visible and invisible molecules are in motion?
Replace this text with your answer.
Remove the slide: Once everyone in your group has viewed the Brownian Motion and you need to remove the slide, be sure to rotate the nosepiece to the scanning objective. Then using the coarse adjustment knob, lower the stage to its lowest position. Then open the stage clip and remove the slide.
Clean up.Rinse any wet mount slides and place them in the container marked “Used slides.” Wash and dry the coverslips and place them in their original container.Throw away any Kimwipes or other paper.You will need your microscope for other parts of this lab, so leave it available. However, make sure it is not near where there is sugar solution. Keep it safe.II. DIFFUSION
Diffusion is the movement of particles from an area of high concentration to an area of low concentration. This results from the continuous random motion that is characteristic of all molecules in liquid or the gas states. A few observations about diffusion will help us to understand how molecules can move from one location to another, perhaps even across cell membranes.
A. Diffusion through a Colloid
The contents of a cell (the cytoplasm) may be described as a colloid rather than a liquid or solid. Large protein molecules are present in a cell's cytoplasm that allow it to be in a transitional state of matter called a colloid (somewhere between a liquid and a solid). A special kind of colloid, agar gel, is available in the laboratory and will be used to demonstrate how molecules diffuse from one place to another once they are inside a cell.
Agar is a carbohydrate extracted from algae in powder form. A gel is prepared by mixing the powder with water, then heating followed by cooling--similar to the preparation of a gelatin (animal protein) dessert. The result is a gelatin-like substance composed of intertwined molecules with water trapped among them. Two compounds (molecules), potassium permanganate and methylene blue, have been selected to illustrate diffusion through a colloid. Unlike most components of living cells, these compounds are brightly colored, allowing us to watch their diffusion.
Procedure:
1. Working with your team, obtain a disposable Petri dish containing agar gel.
2. Using a No. 5 cork borer (a "punch"), make two holes in the agar approximately 5 centimeters apart (See diagram below). Remove the plugs of agar with a toothpick and place in the trash.
3. Bring your agar dish, the dropper bottles of potassium permanganate solution and the dropper bottle of methylene blue back to your lab bench.
4. Place two drops of 1% potassium permanganate solution in one of the holes. In the other hole, place two drops of 1% methylene blue solution. Start a timer for 60 minutes. Return the bottles back to the side lab benches for others to use.5. After approximately one hour, measure the diameter (in millimeters) of the circle that the solutions diffused.
Potassium permanganate:mmMethylene blue:mm
6. Examine your Petri dish. Shade the agar in the diagram to demonstrate the movement of the solutions in the diagram below. Shade to show where the concentration of the potassium permanganate is higher and where it is lower.
Top view of Petri dish: Side view of Petri dish:
Forensic Science Lab and Disucssion
2 Parts assigment is included..Read well and let me know in casePart 1. Do the lab and completly the documents attachedPar ...
Forensic Science Lab and Disucssion
2 Parts assigment is included..Read well and let me know in casePart 1. Do the lab and completly the documents attachedPart 2. Do the Discussion Assigment and answer to students discussion
PHYS 1111 ASU Interaction of Forces & Objects Motion Physics Lab Report
Attached is the lab and simulator answer the questions.below are helpful videos
PHYS 1111 ASU Interaction of Forces & Objects Motion Physics Lab Report
Attached is the lab and simulator answer the questions.below are helpful videos
The Evolution of Terrorist Groups, science homework help
The Evolution of Terrorist GroupsTerrorist groups have been in existence for thousands of years. For example, in the first ...
The Evolution of Terrorist Groups, science homework help
The Evolution of Terrorist GroupsTerrorist groups have been in existence for thousands of years. For example, in the first century Jewish Zealots were fighting to keep Roman rule out of Judea. Today, Al Qaeda fights against perceived enemies of Islam. In some ways, modern terrorist groups such as Al Qaeda resemble their ancient ancestors in terms of their motivations and some of their tactics; in other ways, they are considerably different. In this Discussion, you consider characteristics that distinguish modern terrorist groups from those in existence prior to 1990. Then you reflect on how terrorist groups have evolved. Examining the evolution of terrorist groups is a useful tool in determining future terrorist threats, which you will do later on in the course. To prepare for this Discussion:Review Chapter 5 in the course text Introduction to Homeland Security: Understanding Terrorism with an Emergency Management Perspective and the book excerpt, "Two Thousand Years of Terror." Reflect on the evolution of terrorism and pay particular attention to the differences between historic terrorist groups and contemporary terrorist groups.Review the course media, "The Spectrum of Terrorist Groups." Focus on the distinct characteristics of the terrorist groups discussed and consider how they developed.Review Chapter 2 in the course text Terrorism in Perspective. Consider the characteristics of historic terrorist groups and their changing philosophies over time.Think about the differences in characteristics between contemporary groups and those in existence prior to 1990.With these thoughts in mind: Post by Day 3 an analysis of the characteristics that distinguish contemporary terrorist groups from those in existence prior to 1990. Then, explain at least one insight you had or conclusion you drew about the evolution of terrorist groups based on completing this assignment. Be sure to support your postings and responses with specific references to the Learning Resources.One and a half page with at least three references.... MULTIPLE USE OF INTEXT CITATION REQUIRED It is important that you cover all the topics identified in the assignment. Covering the topic does not mean mentioning the topic BUT presenting an explanation from the context of ethics and the readings for this class To get maximum points you need to follow the requirements listed for this assignments 1) look at the page limits 2) review and follow APA rules 3) create subheadings to identify the key sections you are presenting and 4) Free from typographical and sentence construction errors. REMEMBER IN APA FORMAT JOURNAL TITLES AND VOLUME NUMBERS ARE ITALICIZED.ReadingsCourse Text: Mahan, S., & Griset, P. L. (2013).Terrorism in perspective(3rd ed.). Los Angeles: Sage.oChapter 2, "History of Terrorism"oChapter 3, "International Terrorism"oChapter 4, "Terrorist Tactics Around the Globe" (pp. 147–154)oChapter 5, "Homegrown Terrorism in the United States"Course Text: Introduction to Homeland SecurityoChapter 5, "Uncovering the Dynamic Nature of Terrorism: History and Change Over Time"Book Excerpt: Martin, G. (2006). Two Thousand Years of Terror. In G. Martin (Ed.), Understanding terrorism: Challenges, perspectives, and issues (2nd ed.). Thousand Oaks, CA: Sage. Website: U.S. Department of State (n.d.). Foreign Terrorist Organizations . Retrieved from http://www.state.gov/j/ct/rls/other/des/123085.htm Website: U.S. Department of State. (2004). Terrorist exclusion list. Retrieved from http://www.state.gov/j/ct/rls/other/des/123086.htm Note: Please scroll down the page for the list of designees.Optional ResourcesArticle: Moore, J. (2001). Evolution of Islamic terrorism: An overview. Retrieved from http://www.pbs.org/wgbh/pages/frontline/shows/targ... MediaVideo: Laureate Education, Inc. (Executive Producer). (2010). Terrorism: Legislation and policy: The spectrum of terrorist groups. Baltimore: Author.
UArizona Global Campus Wk 3 Sustainable Management of Water Resources Questions
Question 1:
Prior to beginning work on this discussion forum, review Chapter 5 in the course textbook.
Imagine that you ar ...
UArizona Global Campus Wk 3 Sustainable Management of Water Resources Questions
Question 1:
Prior to beginning work on this discussion forum, review Chapter 5 in the course textbook.
Imagine that you are a resident of Arzaville, a community whose characteristics are described below. You have come together with your neighbors for a special meeting to devise a plan for managing its water resources more sustainably by 2050. Water resource issues the community faces include ensuring a safe and sustainable drinking water supply for all, handling its wastewater in a manner that has a minimal environmental impact, and managing its stormwater runoff in a way that minimizes the risks of erosion and flooding.
Fortunately, you have all attended the meeting with the knowledge that you have gained from your readings in this course. Now it is time to put your thinking cap on and get to work! Your ideas should each consist of one of the following elements, depending upon what you think is Arzaville’s area of greatest need:
Sustainable drinking water access measures (e.g., developing a program for rural residents to begin collecting and treating their rainwater for drinking use).
Sustainable wastewater management measures (e.g., collecting greywater from area residences for use irrigating a local golf course).
Stormwater management measures (e.g., requiring that permeable pavement be used for all future development projects in the community).
This week’s discussion will take place in an online app called Tricider. There, you will be able to post your ideas for plan components and also share pros and cons of different proposals during the week. Finally, you will be able to vote on the three components that you think the plan should include. For directions on how to use the Tricider app, please review the Tricider Help Guide download. In Tricider. You will be expected to do the following:
Post at least two separate and entirely original ideas. Do not duplicate ideas already posted by your peers.
Include your full name for each one.
Post at least six different pros and six different cons for your classmates’ proposed ideas (12 in all).
Vote on what you feel are the top three ideas in the list.
Do not vote before Friday, so that you can vote from the full collection of student ideas.
You must complete the three tasks above to receive full credit for this discussion.
Please note: You are welcome to post questions and comments to this board for your instructor; however, this discussion board does not have any posting requirements of its own, and no additional credit will be given for posts made here.
In this discussion area, the instructor will post the following:
The Arzaville description you will be using for this activity
The link you will be using to access Tricider for this activity.
Tricider Link:
http://www.tricider.com/brainstorming/36bMrwt1Ugl
Question 2:
Prior to beginning work on this discussion forum, read Chapters 5 and 6 in your course textbook.
Now that you have cast your votes for the Arzaville Water Management Plan, it is time to explain your choices to the class. Please make a post of at least 150 words in which you
Identify (briefly) the plan elements on which you voted.
Explain why you selected each one.
Complete worksheets
Week 16 - Climate_and_the_Cryosphere.pdf - Complete this attached file.Week 17 - Layers of the Atmosphere.pdf - Complete t ...
Complete worksheets
Week 16 - Climate_and_the_Cryosphere.pdf - Complete this attached file.Week 17 - Layers of the Atmosphere.pdf - Complete this attached file.Thank You.
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BIO 120 Grossmont College Difussion & Osmosis Worksheet
Exercise 6 - DIFFUSION AND OSMOSISStudent Learning Outcomes
At the completion of this exercise you should:
(l) Be able ...
BIO 120 Grossmont College Difussion & Osmosis Worksheet
Exercise 6 - DIFFUSION AND OSMOSISStudent Learning Outcomes
At the completion of this exercise you should:
(l) Be able to define the terms diffusion and osmosis.
(2) Be able to list and discuss four mechanisms that cells use to move molecules across their plasma membranes.
(3) Be able to explain what Brownian motion tells us about atoms and molecules.
(4) Be able to explain the relationship between molecular weight and the rate of a molecule’s diffusion.(5) Be able to list the characteristics of molecules that can, and those that cannot, move passively across a cell’s plasma membrane.
(6) Be able to describe how the solute concentration, inside of a cell, affects the rate (speed) of osmosis.
(7) Be able to define the following terms: concentration gradient, selectively permeable membrane, hypertonic, hypotonic, isotonic, and homeostasis.Introduction
Virtually all life forms are composed of cells. The cell is called the fundamental unit of life because within it occur most of the biochemical life processes. One of the phenomena of life is that the chemical composition of a cell remains fairly constant, in spite of the fact that the cell continually uses substances from its external environment and at the same time discharges other substances into its environment: This state of chemical constancy in living systems is called homeostasis. This homeostasis, in addition to the fact that a cell's surroundings are always of relatively different chemical composition from its inside, leads us to hypothesize that there must be some very selective means of chemical exchange across a cell's plasma membrane. Today, we will investigate the processes of movement of some substances into and out of cells.
Question 1. Most "cells" do not appear to have an obvious "mouth" or other visible structures in their cell ("plasma") membranes. Suggest one other way in which materials might be able to pass through the cell's membrane:Replace this text with your answer.
Question 2. Cell biologists tell us that there are 4 basic mechanisms that cells use to get molecules across their membranes. You need to learn these 4 strategies. Go to your textbook, or other reference source, and define the following 4 mechanisms:
1.)Osmosis2.)Facilitated diffusion3.)Endocytosis and exocytosis4.)Active transport
Brownian Motion
Robert Brown made an interesting observation in 1827 that led to the principle that "all atoms and molecules" are in constant motion. Dr. Brown was a botanist and army surgeon who was looking at particles inside pollen grains when he noticed the "rapid oscillatory motion of microscopic particles." He later observed the same movement when looking at substances, like India Ink. India Ink is made of water and billions of suspended clumps of carbon atoms. Under high magnification, Brown observed that the clumps of carbon atoms were vibrating wildly in all directions. He hypothesized that moving water molecules, which cannot be seen, must be colliding with the clumps of carbon, forcing them to move. Further study has shown that Dr. Brown was correct and, today, we call this kind of observation "Brownian motion".
A physical scientist would tell you that particles (atoms and molecules) are moving because "they have heat energy (Kinetic energy)". If you ask what kinetic energy is, you will be told that it is "random molecular motion" which, of course, is a circular argument. The point here is that we really do not know the ultimate reason why all atoms and molecules on earth are moving, only that they are and that the more heat energy ("kinetic energy") atoms or molecules have, the faster they move.
You are about to make this observation under the compound microscope yourself. The proper way to carry the compound microscope will be demonstrated. Always use two hands. Make sure that the cord is not dangling to prevent a tripping hazard. One hand should be holding the base of the microscope, while the other should hold the arm of the microscope.
Before using the microscope, check for the condition the microscope was left in from the prior class.
Was the microscope placed back in its assigned compartment with the arm facing out toward you?Was the cord wrapped between the stage and objectives with the plug tucked inside the cord?Was the cord relatively untangled?Was the ocular lens clean? (If not, clean the dirty lens with the appropriate lens cleaner and lens paper (not a paper towel).Was the light turned off?Check that the Condenser is at its highest point, directly below the stage. There is a knob connected to the Condenser that allows it to be moved up and down.Was the mechanical stage centered so that the stage clips don’t hang over the edge of the stage?Was the scanning objective lens (4x) (not another objective) placed over the stage? If not, rotate the nose piece until the scanning objective is facing the stage. Was the stage lowered to the lowest setting possible position? If not, use the coarse focus knob to do so, not the fine focus knob.Were there any slides remaining on the stage? If so, remove the slide and notify your instructor. It is important that the slide is placed in the correct box, or it may get lost.If any of these conditions were problematic, please let your instructor know.
Procedure:
Plug in the cord and turn up the light intensity.to its maximum value and adjust the iris diaphragm to its most closed setting. As you proceed you can increase the light passing through the specimen by gradually opening the iris diaphragm.
Adjust the distance between the oculars: Without placing the prepared slide on the stage yet, look through the oculars. You are likely going to see two circles of white light. Do not try to focus your eyes on any one thing, as nothing is in focus yet. Slowly, move the two oculars together and/or further apart until the two circles of white light become one circle of light, the Field of View.
Lower the stage using the coarse focus knob, and make sure the (shortest) scanning objective is facing the stage, so that there is no chance of the slide scratching any objective lenses.
Prepare your wet mount slide. Wash and dry a glass slide. Place a small drop of India ink on a clean slide. Place a cover slip on the slide.
Coverslip: Carefully cover the preparation with a clean plastic coverslip as follows:
Place one edge of the coverslip near to the drop. The stain and water with which you mixed the cells will flow along the junction of the edge of the coverslip and the slide. Carefully lower the coverslip over the specimen keeping the edge of the coverslip in contact with the slide. In this way, the water will flow slowly and uniformly about the specimen and force out air bubbles from beneath the coverslip. (A few air bubbles are not a serious problem for your first slide.)
Excess fluid: If liquid spills out or may spill out from under the coverslip, gently blot the excess with a towel, so that it will not later drip onto the stage of the microscope. Before looking through the eyepiece (ocular), open the stage clip, and place the slide on the stage of the microscope beneath the objective, with the coverslip visible on the upper side. The stage clip should be holding the slide in place, not pressing the slide under it. Using the left and right/up and down stage knobs), center the object below the objective without looking through the oculars. Nothing is in focus yet.
Coarse adjustment with scanning lens: With the scanning lens in place, move the stage up to its highest point without looking through the oculars. Nothing is in focus yet.
Looking through the ocular with your right eye only (squint or cover your left eye), bring the specimen into focus by turning the coarse focus adjustment knob slowly until the specimen is generally in focus. Then turning the fine adjustment knob will bring the specimen into sharper focus.
Focus your left eye: Viewing the specimen with both eyes through both oculars, turn the left ocular diopter until the specimen is clear in both eyes.
Iris diaphragm: The light coming through the microscope may be either too bright or too dim. If the amount of light is not satisfactory, it can be adjusted by carefully regulating the size of the opening of the iris diaphragm by moving the lever beneath the stage. The iris diaphragm is part of the condenser which concentrates the light coming from the light source.
Adjusting on low and high power objectives - use fine adjustment knobs only: If you wish to view the specimen using higher magnification, center the specimen in the field, and carefully rotate the revolving nosepiece to bring the next higher power objective into place beneath the body tube. The specimen will no longer be in focus. In order to sharpen the image of the specimen, adjust the focus using only the fine focus adjustment knob. (Again, the light may have to be adjusted with the iris diaphragm.) Each time you move to the next higher power objective, be sure you center the specimen beforehand.
Examine the drop first under scanning, then low power, then under high power. Be sure you can see the individual particles of India ink.
Focus your attention on one particle (under high power) for several seconds. Look for a slight but vigorous movement of this particle, independent of the other particles. (Note: You may need to wait a few minutes. Then, if you see a mass "flowing" movement of all the particles in one direction like a small river, this is not Brownian motion. Wait for the flowing to subside, then carefully observe one particle.)
Question 3. Describe the Brownian motion in your own words:
Replace this text with your answer.
Question 4. Describe, in your own words, how this observation indicates that all visible and invisible molecules are in motion?
Replace this text with your answer.
Remove the slide: Once everyone in your group has viewed the Brownian Motion and you need to remove the slide, be sure to rotate the nosepiece to the scanning objective. Then using the coarse adjustment knob, lower the stage to its lowest position. Then open the stage clip and remove the slide.
Clean up.Rinse any wet mount slides and place them in the container marked “Used slides.” Wash and dry the coverslips and place them in their original container.Throw away any Kimwipes or other paper.You will need your microscope for other parts of this lab, so leave it available. However, make sure it is not near where there is sugar solution. Keep it safe.II. DIFFUSION
Diffusion is the movement of particles from an area of high concentration to an area of low concentration. This results from the continuous random motion that is characteristic of all molecules in liquid or the gas states. A few observations about diffusion will help us to understand how molecules can move from one location to another, perhaps even across cell membranes.
A. Diffusion through a Colloid
The contents of a cell (the cytoplasm) may be described as a colloid rather than a liquid or solid. Large protein molecules are present in a cell's cytoplasm that allow it to be in a transitional state of matter called a colloid (somewhere between a liquid and a solid). A special kind of colloid, agar gel, is available in the laboratory and will be used to demonstrate how molecules diffuse from one place to another once they are inside a cell.
Agar is a carbohydrate extracted from algae in powder form. A gel is prepared by mixing the powder with water, then heating followed by cooling--similar to the preparation of a gelatin (animal protein) dessert. The result is a gelatin-like substance composed of intertwined molecules with water trapped among them. Two compounds (molecules), potassium permanganate and methylene blue, have been selected to illustrate diffusion through a colloid. Unlike most components of living cells, these compounds are brightly colored, allowing us to watch their diffusion.
Procedure:
1. Working with your team, obtain a disposable Petri dish containing agar gel.
2. Using a No. 5 cork borer (a "punch"), make two holes in the agar approximately 5 centimeters apart (See diagram below). Remove the plugs of agar with a toothpick and place in the trash.
3. Bring your agar dish, the dropper bottles of potassium permanganate solution and the dropper bottle of methylene blue back to your lab bench.
4. Place two drops of 1% potassium permanganate solution in one of the holes. In the other hole, place two drops of 1% methylene blue solution. Start a timer for 60 minutes. Return the bottles back to the side lab benches for others to use.5. After approximately one hour, measure the diameter (in millimeters) of the circle that the solutions diffused.
Potassium permanganate:mmMethylene blue:mm
6. Examine your Petri dish. Shade the agar in the diagram to demonstrate the movement of the solutions in the diagram below. Shade to show where the concentration of the potassium permanganate is higher and where it is lower.
Top view of Petri dish: Side view of Petri dish:
Forensic Science Lab and Disucssion
2 Parts assigment is included..Read well and let me know in casePart 1. Do the lab and completly the documents attachedPar ...
Forensic Science Lab and Disucssion
2 Parts assigment is included..Read well and let me know in casePart 1. Do the lab and completly the documents attachedPart 2. Do the Discussion Assigment and answer to students discussion
PHYS 1111 ASU Interaction of Forces & Objects Motion Physics Lab Report
Attached is the lab and simulator answer the questions.below are helpful videos
PHYS 1111 ASU Interaction of Forces & Objects Motion Physics Lab Report
Attached is the lab and simulator answer the questions.below are helpful videos
The Evolution of Terrorist Groups, science homework help
The Evolution of Terrorist GroupsTerrorist groups have been in existence for thousands of years. For example, in the first ...
The Evolution of Terrorist Groups, science homework help
The Evolution of Terrorist GroupsTerrorist groups have been in existence for thousands of years. For example, in the first century Jewish Zealots were fighting to keep Roman rule out of Judea. Today, Al Qaeda fights against perceived enemies of Islam. In some ways, modern terrorist groups such as Al Qaeda resemble their ancient ancestors in terms of their motivations and some of their tactics; in other ways, they are considerably different. In this Discussion, you consider characteristics that distinguish modern terrorist groups from those in existence prior to 1990. Then you reflect on how terrorist groups have evolved. Examining the evolution of terrorist groups is a useful tool in determining future terrorist threats, which you will do later on in the course. To prepare for this Discussion:Review Chapter 5 in the course text Introduction to Homeland Security: Understanding Terrorism with an Emergency Management Perspective and the book excerpt, "Two Thousand Years of Terror." Reflect on the evolution of terrorism and pay particular attention to the differences between historic terrorist groups and contemporary terrorist groups.Review the course media, "The Spectrum of Terrorist Groups." Focus on the distinct characteristics of the terrorist groups discussed and consider how they developed.Review Chapter 2 in the course text Terrorism in Perspective. Consider the characteristics of historic terrorist groups and their changing philosophies over time.Think about the differences in characteristics between contemporary groups and those in existence prior to 1990.With these thoughts in mind: Post by Day 3 an analysis of the characteristics that distinguish contemporary terrorist groups from those in existence prior to 1990. Then, explain at least one insight you had or conclusion you drew about the evolution of terrorist groups based on completing this assignment. Be sure to support your postings and responses with specific references to the Learning Resources.One and a half page with at least three references.... MULTIPLE USE OF INTEXT CITATION REQUIRED It is important that you cover all the topics identified in the assignment. Covering the topic does not mean mentioning the topic BUT presenting an explanation from the context of ethics and the readings for this class To get maximum points you need to follow the requirements listed for this assignments 1) look at the page limits 2) review and follow APA rules 3) create subheadings to identify the key sections you are presenting and 4) Free from typographical and sentence construction errors. REMEMBER IN APA FORMAT JOURNAL TITLES AND VOLUME NUMBERS ARE ITALICIZED.ReadingsCourse Text: Mahan, S., & Griset, P. L. (2013).Terrorism in perspective(3rd ed.). Los Angeles: Sage.oChapter 2, "History of Terrorism"oChapter 3, "International Terrorism"oChapter 4, "Terrorist Tactics Around the Globe" (pp. 147–154)oChapter 5, "Homegrown Terrorism in the United States"Course Text: Introduction to Homeland SecurityoChapter 5, "Uncovering the Dynamic Nature of Terrorism: History and Change Over Time"Book Excerpt: Martin, G. (2006). Two Thousand Years of Terror. In G. Martin (Ed.), Understanding terrorism: Challenges, perspectives, and issues (2nd ed.). Thousand Oaks, CA: Sage. Website: U.S. Department of State (n.d.). Foreign Terrorist Organizations . Retrieved from http://www.state.gov/j/ct/rls/other/des/123085.htm Website: U.S. Department of State. (2004). Terrorist exclusion list. Retrieved from http://www.state.gov/j/ct/rls/other/des/123086.htm Note: Please scroll down the page for the list of designees.Optional ResourcesArticle: Moore, J. (2001). Evolution of Islamic terrorism: An overview. Retrieved from http://www.pbs.org/wgbh/pages/frontline/shows/targ... MediaVideo: Laureate Education, Inc. (Executive Producer). (2010). Terrorism: Legislation and policy: The spectrum of terrorist groups. Baltimore: Author.
UArizona Global Campus Wk 3 Sustainable Management of Water Resources Questions
Question 1:
Prior to beginning work on this discussion forum, review Chapter 5 in the course textbook.
Imagine that you ar ...
UArizona Global Campus Wk 3 Sustainable Management of Water Resources Questions
Question 1:
Prior to beginning work on this discussion forum, review Chapter 5 in the course textbook.
Imagine that you are a resident of Arzaville, a community whose characteristics are described below. You have come together with your neighbors for a special meeting to devise a plan for managing its water resources more sustainably by 2050. Water resource issues the community faces include ensuring a safe and sustainable drinking water supply for all, handling its wastewater in a manner that has a minimal environmental impact, and managing its stormwater runoff in a way that minimizes the risks of erosion and flooding.
Fortunately, you have all attended the meeting with the knowledge that you have gained from your readings in this course. Now it is time to put your thinking cap on and get to work! Your ideas should each consist of one of the following elements, depending upon what you think is Arzaville’s area of greatest need:
Sustainable drinking water access measures (e.g., developing a program for rural residents to begin collecting and treating their rainwater for drinking use).
Sustainable wastewater management measures (e.g., collecting greywater from area residences for use irrigating a local golf course).
Stormwater management measures (e.g., requiring that permeable pavement be used for all future development projects in the community).
This week’s discussion will take place in an online app called Tricider. There, you will be able to post your ideas for plan components and also share pros and cons of different proposals during the week. Finally, you will be able to vote on the three components that you think the plan should include. For directions on how to use the Tricider app, please review the Tricider Help Guide download. In Tricider. You will be expected to do the following:
Post at least two separate and entirely original ideas. Do not duplicate ideas already posted by your peers.
Include your full name for each one.
Post at least six different pros and six different cons for your classmates’ proposed ideas (12 in all).
Vote on what you feel are the top three ideas in the list.
Do not vote before Friday, so that you can vote from the full collection of student ideas.
You must complete the three tasks above to receive full credit for this discussion.
Please note: You are welcome to post questions and comments to this board for your instructor; however, this discussion board does not have any posting requirements of its own, and no additional credit will be given for posts made here.
In this discussion area, the instructor will post the following:
The Arzaville description you will be using for this activity
The link you will be using to access Tricider for this activity.
Tricider Link:
http://www.tricider.com/brainstorming/36bMrwt1Ugl
Question 2:
Prior to beginning work on this discussion forum, read Chapters 5 and 6 in your course textbook.
Now that you have cast your votes for the Arzaville Water Management Plan, it is time to explain your choices to the class. Please make a post of at least 150 words in which you
Identify (briefly) the plan elements on which you voted.
Explain why you selected each one.
Complete worksheets
Week 16 - Climate_and_the_Cryosphere.pdf - Complete this attached file.Week 17 - Layers of the Atmosphere.pdf - Complete t ...
Complete worksheets
Week 16 - Climate_and_the_Cryosphere.pdf - Complete this attached file.Week 17 - Layers of the Atmosphere.pdf - Complete this attached file.Thank You.
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