HW - 2/29/12

Answer all of the following questions to the best of your ability in complete sentences in the space below.

1. It’s the first day of spring (give or take three weeks)! Regardless, you run outside to get a breath of fresh air. Describe the path that an inhaled molecule of oxygen would travel starting from the nasal cavity. You can write your answer as a list, a diagram, a flow chart, a paragraph, etc.

2. How does breathing work?

3. How does the respiratory system work to maintain homeostasis in your body? Think deeply and be specific. Include an example if possible.

4. Identify stressors that could affect the respiratory system (ex. exercise). Describe how you think the respiratory system can respond to those stressors.

5. What are other systems of the body that the respiratory system will interact with in order to maintain homeostasis? Identify at least two systems and then describe in detail how each works with the respiratory system.

6. How is the respiratory system related to concepts like diffusion, osmosis and active transport?

HW - 2/28/12

Tonight's HW is to complete the CW 71 - Circulatory System analysis questions found on the back of the notes.

Answer all of the following questions to the best of your ability in complete sentences.

1. Describe the path that a red blood cell travels starting from the right atrium. You can write your answer as a list, a diagram, a flow chart, a paragraph, etc.

2. How does the circulatory system work to maintain homeostasis in your body? Think deeply and be specific. Include an example if possible.

3. Identify stressors that could affect the circulatory system (ex. exercise). Describe how you think the circulatory system can respond to those stressors.

4. What are other systems of the body that the circulatory system will interact with in order to maintain homeostasis? Identify at least two systems and then describe in detail how each works with the circulatory system.

5. How is the circulatory system related to concepts like diffusion, osmosis and active transport?

HW - 2/27/12

Read about the situation below and answer the questions to the best of your ability. Use your notes and knowledge about diabetes as well as the textbooks as a reference.

James is 16, athletic and has previously been in good health. Recently, he has been feeling tired and gets very thirsty, even though he tries to get a good night’s sleep and drink water during the school day. Even though he’s thirsty all the time he also has to go to the bathroom to urinate more often than previously. Sometimes, his friends even tell him that his breath smells fruity.

1. What do you think is going on with James? Support your opinion with evidence and logical reasoning.

2. James doesn’t understand your diagnosis. Explain to him how his body usually deals with the sugar (glucose) in his blood in order to maintain homeostasis. For example, what happens when he hasn’t eaten in a few hours and it drops?

You can write a paragraph, you can make a flow chart or diagram, or you can create a numbered list of steps to show how his body maintains homeostasis in this case.

3. Now explain how James’ body is different and how he is not currently maintaining homeostasis.

4. Recommend a treatment for James and describe how it is going to return his body to homeostasis.

5. Last, James tells you that his uncle Dan has been experiencing some of the same symptoms that James has along with trouble with his vision and numbness in his extremities (hands and feet). Dan was a man of normal health until he had a foot injury that prevented him from exercising normally. As a result, Dan is overweight.

What do you think is going on with Dan? How is his condition similar to that of James? How is his condition different? Support your opinion with evidence and logical reasoning.

Notes 23 - Diabetes Basics

Diabetes is trouble regulating blood glucose levels because of a lack of insulin or insulin resistance.

Glucose is the sugar that all of our cells rely upon for energy.

Insulin is a hormone that lowers blood glucose levels by making glucose diffuse into cells and causes glycogen to form.

Glucagon is a hormone that raises blood sugar by breaking down glycogen.

Glycogen is used to store sugar in your liver.

Mid-Winter Recess HW - 2/17/12

Your homework for the break involves three parts.

1. What is Diabetes - Part 1: Gain basic information about diabetes by conducting internet research. Your research notes will be checked in class on Monday, February 27th.

Your notes should include a summary of useful information about diabetes such as:
- the different types of diabetes
- the causes of diabetes
- the roles of insulin and glucose
- the symptoms associated with diabetes
- the long-term health problems associated with diabetes
- ON YOUR OWN - how diabetes is related to homeostasis

Useful resources include:

NY Times Health Guide to Diabetes
PubMed Health - Diabetes

2. Complete the Diabetes Basics quiz on Engrade by 8:30am of Monday, Febraury 27th.

3. Complete Classwork 69 (What is Diabetes? - Part 2).

HW - 2/16/12

Log in to Engrade and take the "Homeostasis Review" quiz. The quiz closes at 8:30 am on Friday.

Study for the quiz.

HW - 2/15/12

Tonight's homework has 3 partss:

1. Complete CW 67 questions.

Answer all of the following questions to the best of your ability and in complete sentences in the space at the bottom of the page.

1. How could oxygen cross the cell membrane if the concentration of oxygen is lower inside the cell than it is outside the cell?

2. How are facilitated diffusion and active transport related to homeostasis?

3. How is facilitated diffusion different from active transport?

4. Some organisms that normally live in pond water contain water pumps. These pumps continually pump water out of the cell. Describe a situation that would reverse the action of the pump.

5. Farming and watering that is carried out in very dry regions of the world leaves salts that accumulate in the soil as water evaporates. Based on what you know about concentration gradients and transport, why does increasing salinity (or saltiness) of soil have negative effects on plant cells?

6. Summarize – Based on this week, how does cellular transport help maintain homeostasis within a cell?

2. Log in to Engrade and take the "Homeostasis Review" quiz. The quiz closes at 8:30 am on Friday.

3. Study for the quiz.

Notes 22 - Active Transport and Facilitated Diffusion

HW - 2/14/12

Finish. Your. Lab Report.

Eggs. vs. Cells

Both eggs and cells . . .

- have a membrane
- have water inside
- can have diffusion/osmosis act on them
- will have their masses/volumes changed by solutions

Only eggs . . .

- are easily visible
- are not alive
- cannot maintain homeostasis
- cannot respond to stress from solutions (the environment)
- are a model for what could happen to cells
- are permeable to sugar and salt (they can diffuse in)

Only cells . . .

- are microscopic
- are alive
- can maintain homeostasis
- can respond to stress from solutions
- are not permeable to sugar and salt (they cannot easily diffuse in)
- are alive

HW - 2/13/12

Tonight's homework is to continue work on the Eggs-periment Lab Report as the final draft is due in class on Wednesday.

Eggs-periment Lab Report Rubric

because you asked for it . . .

Eggs-periment Lab Report Rubric

Eggs-periment Class Data (so far)

HW - 2/10/12

This weekend's homework is to work on the lab report (due Wednesday)!

Revising Your Introduction

Keep these ideas in mind while you revise your work so far..

- Did I start with an interesting, yet sophisticated hook?
- Did I include relevant vocabulary terms with examples that explain them (in order to show the reader that I understand them)?
- Did I clearly state my experimental question?
- Did I craft hypotheses that are specific and measurable?
- Did I show that I understand why we did this experiment and why we used eggs?
- Did I develop hypotheses that include all of the solutions that my experiment will test?
- Did I write using the 3rd person only?

HW - 2/9/12

Tonight's homework is revise your introduction for the lab report and begin drafting your methods section. Additionally. you should review Notes 19 and 20 to best prepare for tomorrow's check-in.

Eggs-periment Lab Report Overview

Below are the main sections that any laboratory report about an experiment (whether it is performed in high school, college, or by professionals) will usually contain. Your lab report about the eggs-periment will be set up using the general format below.

Throughout the lab report, be sure to use the appropriate vocabulary including words like: homeostasis, diffusion, osmosis, membrane, semi-permeable, solution, solutes, concentration, hypotonic, hypertonic, isotonic, etc.

Introduction:
• What should be stated in your introduction?

1. Your Question:

How does __________ affect __________ ?

2. A Hypothesis for each solution used:

If __________ , then __________ because __________.

3. Background information:
E.g., Why eggs?
Use important vocabulary – don’t just write definitions

Methods:
• What should be stated in your methods section?

1. Procedure – detailed (Use paragraphs, past tense, third person)

2. Describe set-up and materials – with diagram

3. Identify independent & dependent variables/constants/control & experimental group

Results:
• What should be included in your results section?

1. Group and class data tables with any supporting calculations


2. Diagrams of each egg solution

Discussion:
1. Using the data you collected, make a statement connecting your hypothesis to the data. Was the hypothesis supported or not supported by the results of your experiment?

2. Provide your best explanation for the data that you obtained. In other words, what happened in the experiment to give you the data that you recorded?
a. For example, what happened to your eggs during the experiment? Be sure to use the terms osmosis, diffusion, and membranes in your answer.
b. Draw a diagram showing what happened to each of the eggs and why it happened in each situation. Did water move into the egg or move out?

3. Investigate how your data compares to the class data (for your experiment). Try to develop possible explanations for any discrepancies.

4. Discuss all sources of error, which may have impacted the results.
a. Discuss each error and the specific impact it may have had on the data and/or how you interpreted it.
b. Discuss the design of the lab set-up – would you make any changes and why?
c. How would you improve the design of your experiment if you were to conduct this experiment again?
d. Based on any and all errors – how reliable then, are the results and your evaluation of your hypothesis?

5. Speculate on the broader meaning of your conclusions – what connections can you make? Are there any practical implications of your work/findings?
a. How can investigations of internal environments be connected to the rest of biology or to your own life?
i. Ex. Why is it a bad idea to drink salt water?
ii. Ex. Why can sugary drinks make you thirsty?
iii. Ex. Why can’t saltwater fish survive in freshwater?

Homeostasis Notes (if needed)

I. External and Internal Environments

A. The environment can be thought of as an organism’s surroundings
1. external environment – the outside world (ex. air temperature)
2. internal environment – the inside of the organism (ex. cells, organs, etc.)
B. The external environment is always affecting organisms
1. When the external environment disturbs an organism and its internal environment, we call that a stress or stressor
2. Organisms need to respond to stress in order to survive

II. Homeostasis

A. Organisms must respond to changes in the external environment to survive. Why?
1. Organisms must maintain a constant internal environment to survive
2. Organisms must maintain balance in their bodies/cells
a. If it is out of ‘balance’ for too long, then an organism will die
b. The process of maintaining a balanced internal environment is called homeostasis

III. Moving materials (Part 1)

A. Living organisms need different materials to be moved in order to survive
1.Food and water need to be moved into the internal environment
2.Wastes need to be moved out to the external environment
B. When there is a lot of a material in a certain area, we say that there is a high concentration of that material
1. When there is very little of a material in a certain area, we say that there is a low concentration of that material
C. Materials naturally move from areas of HIGH concentration to areas of LOW concentration
1. We call this diffusion
2. Basically, “stuff” likes to spread out
D. A thin layer called a membrane separates internal and external environments
1.The membrane keeps the inside in and the outside out and also decides what is allowed to enter the internal environment from the external and vice versa
E. Membranes are usually semi-permeable, which means that they let some materials through easily and some materials cannot pass through
1. Semi = half or somewhat
2.Permeable = will allow passage through

IV. Osmosis (Moving Materials – Part 2)

A. Water can diffuse (move) across a membrane - this is called osmosis
B. So why would water diffuse into or out of an egg?
1. Water was not the only substance inside of a cell – there were many other materials such as fats, sugars, and proteins
2. These materials in the water are called solutes and when dissolved (spread out) in a liquid it creates a solution (mixture of solids and liquids)
3. More solutes (stuff besides water) inside the cell means there is less room for water . . .
a. So the concentration of water is lower when the concentration of solutes is high
b. When two different concentrations of water are separated by a membrane, water can be pulled across the membrane by osmosis

HW - 2/8/12

Tonight's homework is to work on the lab report and bring in the hntroduction (background info, question(s), and hypotheses) for tomorrow's class.

HW - 2/7/12

Tonight's homework is to continue to work on drafting your procedure for the upcoming eggs-periment.

The components that should be included:

- Question(s)
- Hypotheses
- Variables - independent and dependent
- Constants/controlled variables
- Control groups
- Materials
- Procedure
- Diagram of setup
- Data Table

Below are the materials for setup:

- Shell-less eggs in cups filled with vinegar (up to 4)
- Plastic cups
- 250 mL of corn syrup
- 250 mL of 10% salt solution
- 250 mL of distilled water
- 250 mL of vinegar
- Corn starch (for making a corn starch solution with a concentration of your choice)
- Salt (for making a salt solution with a concentration of your choice)
- Electronic balance (scale)
- String
- Ruler
- Beakers for measuring the volume of solutions
- Coffee filters
- Paper towels

HW - 2/6/12

Tonight's homework is to complete Classwork 65. Click the link to access it if necessary.

Away until back...

After almost four years of writing posts for this blog it is time for a sabbatical. There are certainly enough subjects left to write about. For instance, there is the issue whether established echolocation can prevent eye evolution taking off (I think not), as well as more on eyes, issues on flight, on camouflage, etc. I find writing posts and interacting with those who react (thank you all!) most enjoyable. It is just there are things I need to take care of, and the blogging batteries need recharging. I do not know when I will resume writing, but a nice time to do so would be sometime around the blog's fourth birthday (that's in April, in case you wonder). That is not a definite promise though.

This does not mean that the Furaha project is in any danger. After 30 years I am not going to drop it now. Far from it, in fact: I intend to devote part of the time I have spent blogging on painting. There's lots of things to do.

As proof that the project is very much alive, I can tell you that Furaha will appear in a film that you can actually see in a cinema. The film is being produced by an independent company and is being shot right now. I cannot say too much about it, but it is not a documentary; it will be about people, right here on Earth, and the Furaha project plays a very interesting role.

The producer recently asked me to make -with two days notice, but such things always seem to work that way- a 3D model of my woolly-haired shuffler, an animal that they had seen in my newspaper interview (here and here). and so I loaded Sculptris, a program I wrote about earlier, and started making one. Sculptris is completely free and a joy to work with. The resulting model is certainly not perfect, but for someone like me with limited experience with digital 3D sculpting programs it did not turn out too bad, I think. Particularly if you consider that this was done in about four hours of time...

Click to enlarge; copyright Gert van Dijk

Here are some screen shots of Sculptris with the model in various colours. It was a bit difficult to get the lateral jaws in there, as Sculptris does not formally accept holes. What i did was to push two extrusions together and then I flattened them where they toch one another. Formally, there are no holes in the model...

Once I had that, it wasn't difficult to export the model to the 'obj' format, import it into Vue Infinite and make a 'turn table animation'. That is what you see above. Not too bad, is it?

With the 'obj' model at hand, I decided to have a better look at a website I had visited before. The site, by the firm 'Shapeways', provides a service through which you upload a 3D computer model, and they then check it, print it in 3D and ship it to you. The instructions on how to check the model and upload it were fairly straightforward, so all was left was to choose a material. You can choose various materials with different qualities, such as the ability to hold detail. I chose a material that promised to allow details and settled for a small size, as you pay for the volume of the material used.

Click to enlarge; copyright Gert van Dijk

The model arrived within in two weeks and looked good. Part of the left maxilla had broken off, not too surprising if you consider how thin it was. The website has lots of information on how to prevent making your models too thin. What I had not foreseen is that the material was transparent, so much of the detail did not show up. I painted it to solve that, and photographed the result. Interesting, isn't it? I was impressed with the details, but would like a larger size next time. You pay for the volume of material that goes into the model, so I will have to learn how to hollow out the model; if I manage that, I should be able to order a much bigger one for the same price.

So, it's off towards the sunset for me, for a while. I intend to keep on replying to questions here and on the Furaha bulletin board in the meantime, so I'm not away altogether.

HW - 2/3/12

This weekend's homework is to complete Classwork 64B. The questions are found below.

1. Why did the onion cell change shape when exposed to the salt solution? Explain in detail.

2. Observe the picture below and draw a picture of what you think the Cell A would look like if it was placed in a 10% salt solution (which is 90% water.)



3. After it has been in the salt solution, what chemical could you add to Cell A to change it back to how it looked originally?

4. How does today’s activity relate to homeostasis?

HW - 2/2/12

Tonight's homework is complete CW 63 (on the back of Notes 19). Additionally, there will be a very short quiz about this week's new material tomorrow.

HW - 2/1/12

Tonight's homework is to complete Classwork 62. The questions and associated data table are below.

Answer all of the following questions to the best of your ability in complete sentences.

1. During a long distance run on a hot day, an athlete produces large quantities of sweat. As a result, the kidneys slow down the rate of urine production.

Describe how this action demonstrates the human body trying to maintain homeostasis.


2. In desert environments, organisms that cannot maintain a constant internal body temperature, such as snakes and lizards, rarely go out during the hot, sunny daylight hours. They stay in the shade, under rocks, or in burrows during the day.

Explain how this behavior helps maintain homeostasis in these organisms.


3. Daphnia are aquatic crustaceans that feed on plankton. Populations of 300 Daphnia were exposed to water of different temperatures for 2 days and their populations were tallied afterwards.


a. What inferences can you make based on the data table above?

b. Make a connection between the data in the table and homeostasis.

Notes 18 - Introduction to Homeostasis and Thermoregulation Notes

Based on the BSCS "Behavior and Homeostasis Reading"

1. Homeostasis is maintaining internal balance or a constant internal environment.

2. Examples of homeostasis...

A. Temperature balance
- a lizard moves out of the sun to cool down and maintain a constant body temperature
- a runner starts to sweat to cool down and maintain a constant body temperature
- a woman that forgets her jacket on a cold day starts to shiver to generate heat to maintain a constant body temperature

B. Carbon dioxide balance
- when a person exercises, he or she will breathe faster to get rid of the extra carbon dioxide produce by the working muscles

C. Salt/water balance
- if there is too much salt and too little water in the blood, then the brain will detect this and cause the person to feel thirsty in order to regain water balance

3. Endotherms and ectotherms

- an endotherm is an organism that generates heat internally - for example, warm-blooded animals like mammals and birds
- an ectotherm is an organism that gets its heat from its surroundings - for example, cold-blooded animals like reptiles and amphibians