Revised Blood Cells Sequence

Table of Contents

1. Introduction to microscopes

Introduce students to the procedure of using a microscope.
Lab Safety Quiz
  1. Go over do-now
  2. Review lab procedures
  3. Go to lab!
  4. Practice setting up microscope
  5. Debrief lab time
None.
9/8/08 (Monday)

This day was rather crazy, what with trying to keep students under control while also moving back and forth to the lab teaching them how to use microscopes. I still think it was worthwhile to try to start off with a bang like this.

A few things that made it all run more smoothly:
The big challenge for tomorrow will be to teach kids how to move the slide around on the microscope in a controlled manner - pushing it a short distance instead of removing it entirely.

2. Microscopes Practice

Recognize cells and nuclei under a microscope.
What steps do you need to go through in order to see cells under a microscope?
  1. Go over do-now
  2. Go to lab!
  3. Practice focusing microscope
  4. Talk about cells and nuclei
None.
9/9/08 (Tuesday)

The list we finally generated for the Do-now, once everyone had shared, looked something like this:
  1. Plug in the microscope.
  2. Turn the light on.
  3. Turn the nosepiece to the 40x.
  4. Check through the eyepiece to make sure you can see the light.
    (If you don't see it, you probably didn't click the nosepiece into place properly)
  5. Turn the knob to lower the nosepiece until it is almost touching the slide.
    (It's OK if it touches; it is designed to spring back so you don't cause damage)
  6. Adjust the knob (very slowly!) until you see the cells.
Despite having just gone over the list in the do-now, most groups still haven't gotten the hang of the idea that you need to lower the nosepiece to be almost touching the slide in order to see anything. What seems to work best is to demonstrate it for each group individually with their microscope, talking it through as I do so.

Of course, that's not a practical solution when you have a class of 30. But the whole-class demo doesn't work because all 30 can't get close enough to see. Maybe demo once for each table?

In the wrap-up, I drew pictures of the various cells we've seen: red blood cells, and those other weirder looking cells. In most classes, students were able to guess that those "cells in blood that are red" were red blood cells, and a few students guessed that the other cells, by process of elimination, must be white blood cells.

I defined "cells" as "all those things you saw under the microscope", and "nucleus" as "the dark purple thing inside some cells." More accurate descriptions are unnecessary for this unit. I told students that if they understood the sentence, "All white blood cells have a nucleus," they had all the vocabulary they need for this unit.

3. Introducing the Great Blood Cell Search

Get ready to do The Great Blood Cell Search.
On the second page of your science packet, after the Lab Safety Quiz, is a chart for recording information about cells. Fill in the top half of the first page with information about the Red Blood Cell.
  1. Go over do-now
  2. Introduce The Great Blood Cell Search
  3. Go to lab
  4. Debrief lab time
Blood Cells Worksheet
9/10/08 (Wednesday)

I had to do a lot of explaining in order to get kids to understand what to do for the chart. That was what I expected, but still not ideal, since we want the do-now to eventually become something that we can walk in and hang up and have students start working on it without any words said or questions asked.

The two main questions were: what is meant by "how common?", and what is meant by "texture." I found it useful to develop a word bank of texture words by going around the classroom and looking at the blackboard, the cloth on a bulletin board, the wood grain of the closet doors, and so on, and mentioning words like "bumpy", "grainy", "wrinkled", "swirly", "flat", "smooth", and the like. "How common" just needed to be rephrased as "Are there a lot of them in blood, or are they rare?"

In going over the do-now, we ran into the question of how to talk about the size of blood cells. Obviously, they are all microscopic - too tiny to be seen - but that's not a very interesting piece of information to record, since that will be true of all our cells. So, I introduced the idea of using the red blood cell as the standard for size. I drew up some red and white cells and we decided whether to categorize the white cells as bigger than a red blood cell, smaller, or about the same.

As I was expecting, a lot of students just blindly filled in the "nucleus" section without stopping to think that red blood cells have no nucleus. I repeated the interesting fact that only frogs have nucleated red blood cells. Hopefully that mistake will lead students to think carefully about whether a cell has a nucleus when actually doing the lab.

The size thing will need reviewing before we start the assignment. The word bank of texture words will also have to be provided again.

After the first two classes, I realized that it was a big mistake to start such a large assignment with no sheet describing what students had to do. I quickly made up The Great Blood Cell Search handout, with some examples of how to fill in the cell chart, since that is probably what kids most need to see modeled.

My hope is that the homework will also help to jump-start the lab activity, by showing students actual pictures of all the types of cells they are likely to find and requiring them to recognize which are white blood cells.

4. Finding White Blood Cells

Make sure every student can find white blood cells under the microscope.
Explain what the difference is between the three groups of cells in the picture to the left.
  1. Go over do-now
  2. Go over homework
  3. Review The Great Blood Cell Search
  4. Lab Quiz
Blood Cells Worksheet
9/10/08 (Thursday)



This do-now was quite successful in forcing students to make use of the vocabulary that they have been learning. If you don't have a word for the nucleus, it is almost impossible to think a sentence like "The cells in B have a round nucleus." The discussion brought up that vocabulary, as well as red and white cells.

I took this chance to reiterate that students should copy down whatever is on the board into their notes, since some students did not take notes and thus struggled with the homework. Then I made sure to get the two "facts" that we know so far up on the board to be copied down: "The nucleus is the dark purple thing inside some cells" and "White blood cells all have a nucleus; red blood cells do not."

Going over the homework was a chance to practice using the vocabulary again: we had to discuss which cells on the back were actually white blood cells, based on them having a nucleus, and then in categorizing them we said things like "the nucleus in that type of cells is all squiggly" or "the nucleus takes up almost the whole cell" or "the cell is the same size as a red blood cell."

The goal on the homework was not to get the right categorization, but to practice the process of categorizing. It will be easier in lab because there is color.

I also used the lab handout as a way to practice vocabulary. I asked what was the cell in the top picture, and most students thought it was the dark round thing, since all our cells so far are round. Some, however, figured out that the boxes were cells; some students were even clever enough to look down at the cell characteristics and use that to guide them. That gave us yet another chance to practice talking about the cell and the nucleus. I think most students are finally becoming comfortable with that vocabulary.

In the lab, my goal was to have one lab partner find the right focus, then mess up the focus and let the other partner try, just to make sure that everyone knows how to do that and can do it quickly. One class didn't have time to make it into the lab.

5. The Great Blood Cell Search

Work on The Great Blood Cell Search lab activity.
Get out a writing implement and either your binder, or just the cell charts, and get ready to go to lab.
  1. What quality of work is expected?
  2. Go to lab!
  3. Work on the Search
  4. What did we see?
None.
9/15/08 (Monday)

Class time on the next two days is devoted almost entirely to working on The Great Blood Cell Search. On the first day, I will briefly talk about the standards for what I expect: for example, that students should be able to carefully and accurately draw exactly what they see under the microscope.

The goal of the "What did we see?" debriefing is to give other students hints about what to look for the next day. We might also discuss things like, "Are those little specks around the RBC's actually cells?"

6. The Great Blood Cell Search - Day 2

Work on The Great Blood Cell Search lab activity.
Is the picture shown to the right a white blood cell, or not? Give reasons for your choice.
  1. Go over do-now
  2. Work on the Search
  3. Debrief
Your cell notes from the Search will be passed in tomorrow.
9/16/08 (Tuesday)

Here is the image from the do-now:

I saw a lot of impressive work being done in the lab - some students had found and recorded as many as eight different cell types, and some of your sketches were so good that I could just glance at them and instantly tell what you were looking at. But I also saw a lot of students getting frustrated and not finding anything. So, since this is the first substantial assignment in the class and I want you all to do well on it, I decided on the second day of the search to instead do the activity together as a class by projecting this image on the screen and talking together as a class about the various sorts of cells we saw there.

7. Germs: The Bad Guys

Understand what different kinds of germs the body needs to fight.
Germs: The Bad Guys
  1. Go over do-now
  2. The mystery: "Cursed" fields
  3. Koch and his microscope
  4. Other types of germs
  5. Questions
Anthrax (pdf)
9/17/08 (Wednesday)

This class is at risk for being boring if there aren't enough questions to engage students in the story of Koch and his search for anthrax. So here are some interesting questions to discuss as a class:
  1. If these "sticks" show up in all cows sick with anthrax, is that proof that they cause the disease?
  2. If we know that they do not show up in cows without anthrax, is that now enough to prove that they cause the disease?
    The point here is to differentiate between what might just be a symptom, and what is the root cause. Look at these statements about cause and effect:
    • A great cause of rain is water coming out of the sky.
    • When the top of the pond freezes, this causes the air to become very cold.
    • The weather gets very hot in the summer because people put air conditioners in their windows.
    The point here is that just because two things - a disease and a strange type of cell - appear together, does not mean that one must have caused the other.

  3. Once Koch had shown that blood from a cow dead of anthrax could infect a mouse with anthrax, and that millions more anthrax cells would have appeared in that mouse as it got sick, was that proof enough that anthrax was causing the disease?
    No, because it could still be the case that the anthrax cells were a byproduct of a disease that was carried by something else in the blood.
  4. Check for understanding: Why didn't doctors believe that anthrax cells were dangerous?
    The anthrax cells, when looked at under a microscope, never seem to be doing anything at all. A cell that isn't doing anything is probably not a threat. Many doctors thought that they were simply dead cells from some organ breaking down.
  5. Check for understanding: What did Koch find out was the real reason that the cells were inactive?
    They had either run out of nutrients, having eaten everything available in the cow's blood, or they were at too low a temperature to be able to be active.


8. How do blood cells respond when you get a cut or scrape?

Understand how your body responds to getting a cut or scrape.
List the steps that you observe happening after you get a cut or scrape.
  1. Discuss do-now
  2. Inflammation
  3. Platelets and scabs
  4. The white blood cell response
Infection (pdf)
9/18/08 (Thursday)

The material covered here can be found in the Blood Cell Types section of the online notes.

This class's notes would be great to do as a single giant cause-effect-effect brain frame:
The observed responses are the ones with a double outline, connected by things that are going on behind the scenes. The emphasis, then, is on explaining what we can see based on what is going on invisibly, a common theme in science. So, platelet agglutination is a result of tissue damage, and leads to scab formation; inflammation and white blood cell activity forming pus are other responses.

Hopefully the do-now will generate a list like: heat, swelling, redness, and pain; bleeding, then clear pus, then scab forming.

The homework might be a bit too high level for some kids, but it will be interesting to see how they handle it. I am hoping it provides enough direction that kids can make it through with a sequence of small leaps of understanding. Still, I will have to emphasize the fact that it will require thinking, that it is not just something they can manage by repeating back facts from class.

This homework ought to be collected, right at the start of next class. There could be time to discuss it when it is handed back; there won't be that much time at the start of class tomorrow. It might be interesting, though, to tell a couple of stories about maggot treatment, since that's the one thing on the homework kids are sure to have been surprised by. There was a soldier during WW1 who had been lying wounded on the battlefield for days and whose wounds were full of maggots, but when the maggots were cleared out, the doctor (Baer) saw no infection, but "the most beautiful pink tissue one could imagine." Or Simeon Stylites, a Catholic saint, who was reportedly so caring toward all life that when a maggot would fall out of a wound he had on his leg, he would carefully put it back; the maggots probably saved his life. Maggots don't just clear out dead flesh; they also secrete a complex cocktail of germ-killing chemicals, and promote healing through their movement and through other chemicals they secrete. No one is quite sure why they take such trouble to help out their host.

9. How do white blood cells kill germs?

Understand how white blood cells fight germs.
Vehicle Roles
  1. Discuss do-now
  2. White blood cells move around freely
  3. How do WBC's eat bacteria?
  4. Metchnikoff's experiments
9/19/08 (Friday)

The material covered here can be found in the Blood Cell Types section of the online notes.

As it turned out, this do-now required a lot of explanation, so we ended up doing it together as a class. (That bloated sentence that it started with was particularly egregious; I seem to have just kept tacking on clauses until I ran out of ideas. My English teachers in high school would cringe.)

The first question, then, was "What in the world was I trying to say in that sentence?" The goal was to have students recognize that I was making an analogy between the traffic system and the blood system:
I discussed the idea that in science, often we discover new things by recognizing that some familiar system is similar in some way to the system we are trying to learn about; we can then see if what we know about the familiar system can help us make guesses about the unfamiliar one. In class today, we will think about what we know about traffic, make guesses about what analogous relationships might exist in blood, and then we will hear a story about the scientist who actually discovered that some of those guesses are correct.

For the first question, we listed the types of emergency vehicles, but also listed why they had to be able to get somewhere fast. Then I asked what analogy students thought I was about to make to blood, and we came up with the idea that white blood cells have to get to the site of a cut fast, before germs show up, just as police have to get to the scene of an emergency fast, before things get more serious.

I modified the third question on the do-now to be a little bit more focused: Where do we see a lot of police cars? We had decided in the first question that white blood cells are the "emergency responders" of the blood system, and so we expected them to be moving around on their own in the blood looking for trouble. This problem allowed us to say that, just as police cars gather at a crime scene, we would expect white blood cells to gather at a site of injury.

I also told you that white blood cells have the equivalent of a "police station" that they hang out in. When you go in to the doctor because you are feeling sick, and he feels under your chin, he is trying to feel your lymph nodes. These are little bumps scattered around your body that house white blood cells. There are lots near your mouth - your tonsils are also lymph nodes - because your mouth often gets cuts, and white blood cells have to respond fast when that happens because your mouth has a lot of germs that will try to get in.

What we have just done is to use the similarities between blood and traffic to make some guesses about how white blood cells ought to act. Since they are like police, we said, they will have to move quickly and freely through the body, rather than just going along with "traffic", and they ought to gather at the site of an emergency - that is, a cut or other injury. But how do we know that white blood cells really do act in this way?

The role of white blood cells in fighting germs was first observed directly by Elie Metchnikoff, a Russian biologist working in the late 1800s. This, then, was not long after Koch had first shown that germs could be dangerous. Metchnikoff was trying to answer the question of how starfish digest food, since they have only a small pouch of a stomach directly behind their mouth that does not connect to anything else.

Metchnikoff did a clever experiment in which he fed some tiny bits of red powder to a baby starfish. This is clever because baby starfish are clear, and thus he could see right inside the starfish with his microscope. The grains of powder were sitting on the inside of the starfish's stomach when suddenly a strange cell swam into view, ate up one of the grains, and ran off with it. Metchnikoff watched that cell - labeled, as it was, with the red spot in it - and found that it was patrolling all round the starfish's body. He nicknamed it a "roaming cell;" we now know that type of cell, of course, as a white blood cell.

Metchnikoff began to wonder if what he was seeing was, perhaps, not digestion, but defense. Did that cell somehow think the red powder was something dangerous? He decided to try to figure out if these cells were actively defending the body, and he did this with two rather clever experiments.

First, he went into his wife's garden, plucked a tiny thorn off of a rose bush, and stuck it into the arm of the starfish. After waiting a few hours, he stuck the starfish under his microscope, and looked at the arm near the thorn. As you probably would guess, what he saw was that the whole area was swarming with white blood cells, all gathered to try to fight off this strange invader. Thus, he had proven that white blood cells respond when there is an "emergency" in the body.

Next, he experimented with another favorite animal of his, the water flea, which is also transparent and thus can be inspected through a microscope. As he was watching through a microscope, he noticed a flea accidentally swallow the spore of a fungus - a nasty, spiky little microscopic ball that got stuck in the lining of its stomach. Sure enough, a few minutes later a white blood cell came squeezing through the lining of the stomach, ate up the spore, and carried it off.

Still, just seeing that was not enough to prove that white blood cells defended the body against dangerous threats, because despite the frightening microscopic appearance of the spore, he had no proof yet that it was actually dangerous. So, he kept watching - perhaps he added some more of those spores to the water, and eventually he saw a flea in which a spore had been swallowed and had remained unnoticed by the flea's white blood cells. This spore began spreading out thin white threads of fungus through the body of the flea, growing rapidly and feeding off the flea's body as Metchnikoff watched through his microscope, and in a few hours, the flea was dead.

Thus, Metchnikoff had observed that white blood cells will move toward the site of an injury and carry off germs that are dangerous to the body. He theorized that whether a germ infects us or not is dependent entirely on whether our white blood cells do a good job of recognizing it.

10. Reviewing what we know about blood cells

Review what we know about blood cells.
Which type of blood cells do you think would be most worthy of the slogan "This is Sparta!"? Explain why.
  1. Discuss do-now
  2. Go over homework
  3. Review RBCs and platelets
  4. Cell membranes
White Blood Cells (pdf)
9/22/08 (Monday)

The do-now might require some recap of the movie 300, in case any student hasn't heard about it. Even for the students who have seen the movie, I can share some of the background of the battle that might be new to them. I haven't actually seen the movie myself, but I learned a lot about the battle in high school Greek, Latin, and History classes.

I inserted this day in the schedule to give us a little bit of breathing room, because in the last few classes we've been learning new things right up to the bell. This class will give us time to go over anything that was confusing on the homework, make sure that everyone has a good idea of what red blood cells do (something we have alluded to before, but not directly studied). The interesting questions to talk about concerning red blood cells are why sickle cell anemia has the effect that it does, and why Lance Armstrong has so many red blood cells. We can also talk about people living at high altitude, and about blood transfusions as an increasingly common form of cheating for endurance athletes.

Understanding the fluid nature of the cell membrane is the primary focus of the rest of class. This is a tough idea to wrap one's head around; I think that I really need more examples in order to make it clear. I can pose a variety of puzzles for kids to try to work out, such as what happens when a cell with a vacuole fuses with another cell; they would have to try to draw a cartoon showing the steps that would result.

The question of what it looks like when a cell splits is one that students can hopefully answer by the end of class. The interesting thing to discuss would be what they think happens to the nucleus during that time.

11. More review of blood cells

Review what we know about blood cells.
Have your homework out on your desk and be ready to go over it.
  1. Go over homework
  2. More cell membrane examples
  3. Review body's response to cut
9/23/08 (Tuesday)

Since we didn't have enough time in yesterday's class to really do a good job of discussing cell membranes, today will give us some more time to really get comfortable with the topic. We will also review the steps that result when you get a cut or scrape, since this is the core of our understanding of the immune system and some of the responses I got on homework seemed to indicate that this knowledge is still not comfortable enough that you are all using it readily.

After going over the first problem on the homework, we looked at another example of cell membranes acting in a weird way. Some viruses - a particular type of germ - come wrapped in their own little membrane, as if they were already in a prison vesicle although they are outside a cell. What happens, then, when that membrane fuses with a cell membrane?
You should realize that when the two membranes fuse, the virus ends up inside the cell. And unlike a germ that has been eaten, it is "free" inside the cell, not in a prison vesicle. In fact, even if the cell eats up the virus, membrane and all, it can escape by fusing its membrane with its prison vesicle:
Once the virus is loose inside the cell, it starts to control the cell, forcing it to produce more viruses. Then, each of those viruses can leave the cell, pulling a bit of the cell membrane along to wrap itself in so that it can repeat the same trick on the next cell it encounters.
Remember, it is not important that you know what a virus is or how it works; the point of this sequence of questions was just to help you get more comfortable with how the cell membrane acts.

The next thing we did in class today was to look at this Blood Cell Drama. The second page has listed out all the steps involved in your body's response to a cut or scrape, which we connected up with arrows to show the proper order. Then, we looked at the other page, which has a bunch of crazy-looking cells drawn on it, and I challenged you to figure out what is going on: Identify the skin, a scab, some blood, and some pus. If you can understand everything going on in this picture, you probably know what you need to about your body's response to injury.

12. White blood cells that attack germs

Learn about the types of white blood cells that attack germs.
Looking at the Blood Cell Drama, tell me:
1) How many types of germs?
2) How many types of white blood cells?
3) How are the top skin cells different from the bottom? Why is this?
  1. Go over do-now
  2. I spy...
  3. Neutrophils
  4. Eosinophils
9/24/08 (Wednesday)

The material covered here can be found in the Cell Types section of the online notes.

Looking at the Blood Cell Drama is a good lead-in to todays topic, because you should notice one interesting thing about it: there is only one type of white blood cell present. Although there is no color, we should be able to recognize it from the shape of its nucleus; it is the type that has a pink cell with a strange curvy nucleus.

There are plenty of great things to "spy" in the picture:
The one type of white blood cell that we saw in the drama is called a neutrophil. This is the only type of white blood cell whose job it is to specifically attack germs.Once you understand the last question, you'll be ready to see the next type of white blood cell, called an eosinophil. Eosinophils are very much like neutrophils, except that they have much larger poison vesicles. What do you suppose that means about the germs they hunt?

13. White blood cells that detect dangerous germs

Learn about the types of white blood cells that detect and respond to dangerous, infectious germs.
Eosinophils
  1. Go over do-now
  2. Monocytes
  3. Lymphocytes
WBC Types (pdf)
9/25/08 (Thursday)

The material covered here can be found in the Cell Types section of the online notes.

The do-now is designed to either introduce eosinophils, or review what we know about them, depending on where that particular class got to yesterday. It turned out to be helpful to talk through a few related questions first: Why so big poison vesicles? What is going on in the comic picture?

A good additional question to ask on eosinophils: My twin brother Michael got an awful case of poison ivy on both his arms from helping out on Charles River Cleanup Day last summer. It was so bad he sat for the whole day alternating which arm was in a bath of ice water, and his hands were swollen up like balloons and oozing pus. The strange thing is that poison ivy oil is not actually dangerous to you - it won't cause damage to your body cells at all. However, it does smell a lot like a common type of parasite. Can you connect the dots and tell me where the rash comes from?

We know at this point that neutrophils are able to get to the site of an injury and kill lots of germs, rather quickly. They do this by rapidly swallowing up a germ, poisoning it, spitting out the corpse, and immediately looking for the next germ. The result is that, after a battle, there are lots of germ corpses lying around.

Why would this be a bad thing? The germs are dead; they can't infect or poison you any more. However, they are still dangerous simply because your body will keep "smelling" them and responding as if there are live germs there. Neutrophils might keep swallowing up and killing the same germs, releasing a little bit of poison into your blood each time. The skin nearby will stay red and inflamed. In order to stop all the panic, the dead germs need to be cleared away.

Our next type of white blood cell is called the monocyte. In the pictures I showed in class, the one on the left is what a monocyte normally looks like in your blood; the one on the right is returning from a battlefield. What is different?

You may notice that the monocyte coming back from the battle is carrying a lot of hollow bubbles, the same color as the background. These are prison vesicles; they are the same color as the background because with each germ the monocyte has swallow up, is swallows some of the liquid around it. You would see the same thing if you were ever to look at a neutrophil with a prison vesicle, but this is unlikely, since neutrophils spit germs back out as soon as they swallow them. The monocyte, in contrast, seems to like keeping dead germs around.

You might also notice that the monocyte has no poison vesicles. Clearly, it is not in the business of killing germs; it only ever deals with them once they're safely dead. Monocytes typically show up at the site of an injury a few hours afterward, long after all the fighting is done.

Like police detectives, who arrest people or collect clues at the crime scene, monocytes have a purpose in taking things away with them; they are not just trying to dispose of the mess. Detectives bring all the evidence back to the police station; do monocytes have a "police station" to report back to?

You may remember that your lymph nodes are the place in your body where white blood cells hang out. It is there that the monocytes return with the dead germs. They are met by lymphocytes, the fourth type of white blood cell, who usually live in the lymph nodes. It is the job of the lymphocytes to decide if a germ that has been caught is something dangerous, something that might infect the whole body. If it is, the lymphocytes will spread out into the blood to try to track down other germs of the same type.

You doctor can tell that you are fighting an infection in this way by feeling the lymph nodes under your jaw to see if they are swollen. Just as there is probably something going on in the city when there are police cars swarming around hte police station, there is something going on in your body if the lymph nodes are busy.

Interestingly, lymphocytes do not have poison vesicles either. In other words, they are not able to kill germs themselves. What they do instead is to label the germs that they find and leave them to be killed by the neutrophils.

Here are old notes for a sequence that since has been revised:

I rather suspect that this is actually two days of class, if I take the time to really let kids think through and figure out how things ought to work, rather than just telling them directly. For example, once they have an idea of the various attack mechanisms a neutrophil has available to it - either eating a bacteria and poisoning it internally, or releasing poison to attack it externally - I might ask them how, then, neutrophils would attack an anthrax strand (too big to eat), then use that as a hint as to how they would attack a parasitic worm, then reveal the existence of eosinophils as the "big game hunters" who can really release a lot of poison at once.

The interesting "new" facts are:Here's the notes as they would appear on the board:
Some interesting check-in questions for kids:The homework will not just be a good place to practice identifying cell types; it will also give them some nice big pictures of those cells (though not in color).

14. Go over the test

We will all know enough about blood cells to be able to participate in class in the next week.
Cookie Questions
  1. Pass back test
  2. Go over test questions
  3. Review grading system
  4. Play more of review game
Trouble Problems from Blood Test

14.1. What does you brain need to work?

The do-now will give me some feedback on what kind of cookies to make next time, but the main goal was to remind you of what I told you during induction: that you need water, food, and exercise to keep your brain working. Since I wanted you to do well on the test, I made sure everyone could get water, and I brought in cookies. Sugar is available to your brain for energy far faster than other foods like meat or bread that require more digestion, so eating a sweet snack while working on a tough problem is a great way to keep your brain going.

Of course, if you eat a lot of sugar at once, you'll find yourself first having too much energy to be able to focus, and then about a half an hour later all that energy will drain away and you'll be tired. So part of what you need to learn, in order to manage your own mental state so that you can be focused all the time, is how to provide yourself with the right combination of those three things.

When I'm working, I usually drink a lot of water, although in small sips to prevent me from having to go to the bathroom all the time. I also try to eat a variety of different foods: protein sources like hard boiled eggs and cheese sticks that will provide lasting energy, but also snacks like cookies or raisins that provide a sugar boost when I need it. I also like to have some source of exercise available, even if it's just walking around or doing push-ups.

In school, we can't allow you to all eat and drink and walk around whenever you need to, but we do try to structure all those things into the day. At this stage in your life, you sill be better off having someone guide you; awareness of your own state of focus is something that only develops with a lot of experience.

14.2. Going over the test

The grades for the test were split fairly evenly between very good and very bad, with not a lot of people in between. It was very clear who are the people who have been paying attention and participating in class, and who have not. Hopefully this will serve as a wake-up call to some of you that you are not doing the level of work required by MATCH.

Even if you are disappointed by your test score, I am willing to bet that you aren't surprised. If you got a bad score, I suspect that at some point in the last few weeks, it might have occurred to you that you are hearing a lot of things being discussed in science class and you have no idea what is going on. Now is the time to decide that you don't want to be in that situation any more.

One change that I'm going to make immediately in class, to try to make it harder for anyone to be left behind, is to make lot more use of the whiteboards, requiring everyone to write and hold up a full answer to the questions I ask in class instead of just calling on one person to answer.

The material you are learning here is new to all of you - no one knew anything about blood cells when you came to MATCH. So, any time I'm asking a question, I expect that everyone ought to know the answer, since it will always be a question about something that we've learned in class, not something you may or may not have learned in previous years.

If you do find that you had difficulty answering a question correctly in class, there are also several things that you can do to try to make sure you get back to where you ought to be. The first thing you can do is to let your classmates help you - listen to their answers, write them down if you have to, and ask your classmates for help outside of class. Your tutors are also a great way to get help. You can also ask questions of Mr. Z. at lunch or recess.

There is one other tip I would like to give you for remembering what you learn. Your brain is designed to hold onto a new bit of information only if it is connected to other ideas. This is why I take the time in class to introduce new ideas by building onto the ideas we already have, rather than just listing out facts in a jumble and expecting you to remember them all. The advice that comes out of this is: Make note of connections. Treasure them. Take the time to run along the connecting paths of your own brain, or to try out where a new idea might fit in with what you already know.

A good example of this is trying to remember what all the types of white blood cells do. If you were to just memorize the list of jobs of each one, you could probably succeed in doing so, but you would be making a lot more effort than you need to. An easier way is to make note of how those facts are all connected. For example, the "-phil" cells are both germ killers, and they have a similar appearance because they both have poison vesicles used to kill germs with. If the spots you see in the picture are connected in your mind to the idea of poison vesicles, you will find it easy to recognize those cells in pictures, or to remember that the eosinophil, with larger vesicles, hunts larger prey.

15. Introduce cause/effect brain frames

Learn to create and use cause-effect brain frames.
Explain the following conversation:
"Did you do anything exciting over the weekend?"
"I slept a lot and drank a lot of tea with honey."
"Oh. I hope you feel better soon!"
  1. Go over do-now
  2. Cause/effect brain frames
  3. Example: Chediak-Higashi
  4. Example: HIV-AIDS
10/7/08 (Tuesday)

Drawing conclusions about cause and effect, as the do-now hopefully points out, is something that we all do all the time. In order to understand that little bit of conversation, I need to recognize that sleeping a lot and drinking tea with honey are both effects that usually come from the same cause: being sick. I am using, in my mind, a set of connected ideas that looks something like this:
This way of organizing causes and effects is something we have been using a lot. It is time to teach you exactly what it is and how it works.

This picture is called a cause effect brain frame. Whatever is described in a box is some event that happened. The arrows show what event or events caused others to happen. An arrow from A to B, then, means that A caused B to happen. So, in the example above, drinking lots of tea with honey made me have to go to the bathroom every few minutes.

Our main goal this week is for you to learn how to create a brain frame for yourself:
  1. Whenever you are reading something that describes causes and effects, and...
  2. Whenever you need to answer a question about cause and effect.
Brain frames are a way to help you organize information so that it is easier to understand and easier to write about.

We will look back at some of the homework from last week, just trying to make brain frames to describe what is going on in each. Remember, all that I am doing here is to try to take the information in the problem and connect it up with the processes I already know.

For the Chediak-Higashi Syndrome homework, we can start out with what we are told - that it prevents vesicles from forming - and fill in what will happen as a result. There are two obvious effects - that I won't be able to form prison vesicles, and that I won't be able to form poison vesicles - but a complete response would trace through those effects to see what further effects they create.
For the HIV-AIDS homework, the goal was to fit in the new information I was given with what I already know about blood cells. This is a little bit more challenging; I have a few pieces of information at hand, and I need to remember what comes in between to connect those events. The complete brain frame might look something like this:
Once I have a brain frame for one of these problems, it makes it much easier to answer questions about them:

16. Practice cause/effect brain frames

Learn to create and use cause-effect brain frames.
Basophil
  1. Go over do-now
  2. Complement System
Anthrax Brain Frame
10/8/08 (Wednesday)

The do-now is meant to reinforce the idea that it is easier to figure out and remember things about cells if you look for connections. A basophil looks very much like an eosinophil - large poison vesicles, two-part nucleus - but is different because its poison vesicles are blue instead of red. This might lead you to conclude that, like an eosinophil, it attacks large germs like parasites; you might also conclude that it targets different types of parasites, since it has a different kind of poison.

Yesterday we all worked together to make brain frames based on things we had already studied. Today we are going to try something a little bit harder - reading about something we have not yet studied and trying to put together a brain frame to show what is happening.

The reading we are going to do is about complement proteins. These proteins are floating around in blood all the time, and they like to stick to cell membranes. They also like to stick to each other. If I show you the shape of the protein, I think you can probably figure out what they become when they stick together:
To make it a little bit easier for you, I've already created all the boxes that will go into the brain frame we will be making. We will also read through the first few paragraphs as a class and start to assemble the brain frame together, so that you have something to build on. The goal, however, is for you to do most of this with partners, so that you will be ready to do this kind of thing yourself on the homework.

Complement System

The homework will give you information about something that we have already studied, but it will ask you to assemble that information into a brain frame.

Anthrax Brain Frame

17. What is a good explanation?

Learn how to turn a brain frame into an explanation of causes.
What is a Good Explanation?
  1. Go over do-now
  2. Words to show cause and effect
  3. Brain Frames to Sentences
10/8/08 (Thursday)

The examples you see on the

18. Practice writing an explanation from a brain frame

Learn how to turn a brain frame into an explanation of causes.
Smallpox
  1. Go over do-now
  2. Graft Rejection
Leukocyte Adhesion Deficiency
10/9/08 (Friday)



19. Review for thinking test

Be ready to do the thinking part of the blood test.
Defense in Depth
  1. Go over do-now
10/9/08 (Friday)



20. Cause and Effect Game

Make sure we can all create cause-effect brain frames from what we read.
Cause-Effect Review
  1. Play Cause-Effect Game
Smog and Blood Cells
10/14/08 (Tuesday)

The game is done in pairs, with soft voices. The rules for this kind of group work are:

The rules of the game are listed on the do-now, so that everyone can see exactly what they are, but we'll also go over them as a class. We have until five minutes before the bell to do as many as we can. Then we have to stop to get desks back in place. There are lots of easy brain frames you can try to get points you can be certain of, but the real payoff comes with the harder ones.


21. Patterns for writing cause-effect sentences

Learn some simple patterns for writing about cause and effect.
Brain Frame Corrections
  1. Go over do-now
  2. Simple pattern for writing cause-effect sentences
  3. Writing better sentences
Leukocyte Adhesion Deficiency
10/15/08 (Wednesday)

I started collecting the do-now, instead of giving demerits for incompletion; that way, the vast majority of the class will benefit from having done the do-now instead of a few kids being hurt by the fact that they don't know what's going on.

In designing this do-now, my thought was that, in order to do well on the test, students will have to be able to notice all the little details that might make a cause-effect brain frame wrong. Asking them to correct errors makes it easy to make note of the details, since the bulk of the problem is already done and you can't justify that you have done enough work simply because you made a bunch of boxes and connected them in some random order.

I spent a lot of time on the do-now, but I think it was worth it - several students are finally getting what's going on as a result.

I didn't actually make use of the Cause and Effect examples to make sentences out of; I just wrote a few brain frames on the board and had students generate sentences.

22. Cause and Effect Review

Be prepared for the test tomorrow.
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  1. ???
Leukocyte Adhesion Deficiency
10/14/08 (Tuesday)