Klug, Old Activity 7.2, Nondisjunction

Klug, Old Activity 7.2, Nondisjunction

Klug, NEW Activity 7.2 Chromosome Separation in Meiosis: Disjunction

Klug, NEW Activity 7.3 Polyploidy

In its revised format include old 7.2.1 through 7.2.8 and add a summary page and Post-quiz. It will have it's own Introduction, Summary, and Post-quiz.
Remove the screen asking if the user wishes to take the quiz.

NOTE TO ANIMATOR FROM MURRAY: THE OVERVIEW OF MEISOIS ANIMATION IN THIS HAS ALREADY BEEN DONE BY JOSH, SO YOU CAN USE THAT AGAIN—SAVE TIME & MONEY.

New organization:

Activity 7.2, Chromosome Separation in Meiosis: Disjunction

Introduction (New 7.2.1)

-This will not be programmed as a Flash animation.

-This will be converted into an html page.

-The title over the image will read "Chromosome Separation in Meiosis: Disjunction".

-The introduction text will be different (see below) but will use the first image of the existing animation (the spectral karyotyping of human chromosomes, old 7.2.1.1) shown as a static image on the Intro page.

-Discard the 3 screens of text from old 7.2.1.

-Change the first text paragraph to say “Disjunction is the separation of chromosomes during anaphase I and II in meiosis. After fertilization the four resultant zygotes have both members of each homologous pair (in this case, of the one homologous pair carried in the diploid cell) and are said to be disomic (normal).”

-Add a second following paragraph: “Sometimes the chromatids of a tetrad or dyad (doublet) fail to separate in meiosis I or II. This event is called non-disjunction. The products of non-disjunction are aneuploid, a condition in which the chromosome number is not an exact multiple of the haploid (1n) cell. In this tutorial you will examine chromosome disjunction errors that can occur during meiosis and how the gamete genomes are affected by these errors."

Animation (New 7.2.2) Overview of Meiosis

-The old version contains 3 scenes, each with its own text. The new version will omit the requirement for a “Play” button. For each scene, follow this order:

show the static graphic
scroll in the text
pause
show the animation
pause
dissolve the text and start the next scene

-Scroll the text from the bottom until the last line reaches the third line down from the top of the text window. Freeze the scrolling at this point, pause 1 seconds, and play the animation.

-In the second paragraph of the first scene, change the first sentence to read “The animation at left will illustrate the partitioning…”

-In the first paragraph of the third scene, change the first sentence to read “The first meiotic division is followed by a second…”

Animation (New 7.2.3) Errors in Disjunction

-Add the following scroll flags

At start of New 7.2.3 1: flag as “Normal Disjunction”,

At start of New 7.2.3 2: flag as “Non-disjunction at Meiosis I”,

At start of New 7.2.3.3: flag as “Non-disjunction at Meiosis II”

At start of New 7.2.3.4: flag as “Fertilization”

-Scroll the text upwards from the bottom until the top line reaches the top of the text window, then freeze. Start the animation just after the text freezes.

-Remove all stops in the animation. One scene will automatically move into the next. Adjust the timing to allow a few second pause between each scene.

-In the second paragraph of the first scene of Normal Disjunction, change the first sentence to read “The animation at left will illustrate normal disjunction…”

-Place the title “Non-disjunction at Meiosis I” at the top of the second scene.

-In the second paragraph of the first scene of Non-disjunction in Meiosis I, change the first sentence to read “The animation at left will illustrate non-disjunction in the first division…”

-In the second paragraph of the last scene of Non-disjunction in Meiosis I, change the first sentence to read “The animation at left will illustrate the outcomes of fertilization…” The last part of the animation of Non-disjunction in Meiosis I should be timed after the last page of text scrolls in. This is the last scene of the flagged Non-disjunction in Meiosis I.

-Place the title “Non-disjunction at Meiosis II” at the top of the third scene.

-The last scene of this animation segment is “Fertilization.” It will contain use the full width of the window and will NOT have scrolling text. Add a few second pause before showing the second part of the graphic.

-This is the end of this segment.

Exercise (New 7.2.4) Creating Non-disjunction in Meiosis I

-This is self-contained.

-Change the title to “Creating Non-disjunction in Meiosis I” (Old Nondisjunction at Meiosis I)

-Delete the first screen (old 7.2.7.1 with text instructions at the right) and go directly to the exercise at old 7.2.7.2. This screen shows 8 boxes of chromosomes in the text area.

-Delete the gray popup box called Exercise Instructions which currently appears automatically.

-In the Instructions popup box for this exercise, write: “A diploid cell with 4 chromosomes (one pair metacentric, the other telocentric) begins meiosis. Drag each box of chromosomes to the correct spot in the chart in order to obtain the haploid set of chromosomes described underneath each of the gametes. Not all of the boxes will be used.”

-Keep the same drag and drop interactivity.

-Delete the final popup box that says “You’re finished!” along with the “Continue” button.

-This is the end of the exercise.

Exercise (New 7.2.5) Creating Non-disjunction in Meiosis II

-This is self-contained.

-Change title to Creating Non-disjunction in Meiosis II (Old Nondisjunction at Meiosis II)

-Delete the first screen (old 7.2.8.1 with text instructions at the right) and go directly to the exercise at old 7.2.8.2. This screen shows 7 boxes of chromosomes in the text area. This is the interactive portion.

-Delete the gray popup box called Exercise Instructions, which currently appears automatically.

-Keep the same drag and drop interactivity.

-Delete the final popup box that says “You’re finished!” along with the “Continue” button.

-This is the end of the exercise.

Summary (New 7.2.6)

-Use the following text as the Summary. This will be programmed as an html page.

Summary  Chromosome Separation in Meiosis: Disjunction

Disjunction is the separation of chromosomes during Anaphase I and II in Meiosis. Zygotes that result from normal gametes which participate in fertilization are disomic in that they carry both the paternal and maternal members of each homologous chromosome set (and no more).

Sometimes the chromatids of a tetrad or dyad (doublet) fail to separate in meiosis I or II. This event is called non-disjunction. The products of non-disjunction are aneuploid, a condition in which the chromosome number is not an exact multiple of the haploid (1n) cell.

Non-disjunction in Meiosis I produces two gametes with two members of a homologue set (they are diploid for that set) and two gametes lacking a representative of that particular chromosome (they are deficient for that set).

Normal fertilization of Meiosis I non-disjunctive gametes produces two trisomic and two monosomic zygotes.

Non-disjunction in Meiosis II produces two normal gametes, one gamete with two copies of a chromosome (two chromatids, which makes it diploid for this set) and one gamete lacking any chromosome representative for that chromosome set.

FirstPass Comments from Eric Stavney10/23/03

Let’s enlarge the font size for the caption on the graphic on the Introductory Page. It can be as large as the text size. Right now it’s too small.

[Andy 10/24: No, delete the caption from the art and add it as a HTML label below the graphic.]

The second sentence of text on the Introduction page doesn’t make sense and I’m not sure what we originally wanted here. I would change the sentence to read: “After fertilization the four resultant zygotes have both members of each homologous pair (in this case, of the one homologous pair in the diploid cell) and are said to be disomic (normal). [the word “called” has been deleted].

[Andy 10/24: The sentence was not keyboarded correctly. The word “called” should have been “carried.” It is appropriate to delete the word “called” to correct the error.]

In 7.2.2.1 there are punctuation errors at the end of the second paragraph of text. The last sentence of the second paragraph should properly read –without parentheses and without the double period: “Recall that chromosome duplication has already occurred during an earlier stage of the cell cycle, before meiosis begins.”

[Andy 10/24: Please make this change.]

[Andy 10/24: In the first (and all) exercise, the instructions should be open by default then close after 5-6 seconds.]

In 7.2.2.1, the third text unit/sequence that begins “The first meiotic division is now followed by a second division….” , change the last word of the first paragraph from “MONADS” to “monads”. [lowercase, italicized]

[Andy 10/24: Please make this change.]

In 7.2.2.1, the fourth text sequence contains an entire paragraph that doesn’t belong. The text sequence begins “Aneuploidy results from an error…..” and the paragraph that should be deleted (third one) begins “The filter is removed from the bag and washed to remove……”

[Andy 10/24: Please make this change. Delete the paragraph that begins with the sentence “The filter is removed from the bag and washed to remove the excess probe. Hybrides…” Do not delete the paragraph that follows this one.]

In 7.2.2.2, right at the scroll flag Non-Disjunction at Meiosis I, the static text jumps downwards by a couple lines just before the transition to the scrolling of the new text sequence. Fix it so the text doesn’t jump after it has finishes scrolling and fades out without the jump.

[Andy 10/24: Please make this change. I believe that Eric is talking about the transitions between Normal Disjunction, Non-disjunction in Meiosis I, and Non-disjunction in Meiosis II. The elements do not align between the segments and the transitions makes them jump. Because these are really different discussions, it is necessary to use a slow, soft fade of the first screen then a hard cut for the second. It needs to be obvious that we’re wiping the slate and beginning a new discussion. It would also help to choose a new color for the beige box that contains the titles of the stages in Non-disjunction in Meiosis II. Change the color to a blue similar to the blue used for the chromosomes. This should help make the point that it’s a different discussion.]

Also in 7.2.2.2, right at the scroll flag Non-Disjunction at Meiosis I, the graphic needs to dissolve (fade out and fade in the new) instead of abruptly cut to the new sequence.

[Andy 10/24: Use a soft fade out and a hard fade in.]

Within 7.2.2.2, during the scroll flag section Non-Disjunction at Meiosis I, the last line of text needs some punctuation fixed. This is the last line of the paragraph that begins “Besides being laborious and time consuming…..”. The last sentence should have the commas removed to read” “Most of these clones will not be adjacent to the clone from which the probe was derived and the walk will be terminated.”

[Andy 10/24: Please make this change.]

In 7.2.2.3, right at the scroll flag Non-Disjunction at Meiosis II, the transition from the extant graphic and text needs to be a dissolve, not a blunt cut. Fade out the old and fade in the new.

[Andy 10/24: See my earlier note. Use a soft fade out and a hard fade in.]

In 7.2.2.3 in the scroll flag section Non-Disjunction at Meiosis II, the second paragraph that begins “The animation at left will illustrate….” needs a period at the end of the sentence, after the word “nondisjunction”.

[Andy 10/24: Please make this change.]

In 7.2.2.3 in the scroll flag section Non-Disjunction at Meiosis II, the fourth paragraph that begins “When these products of oogeneis are instead….” needs a correction to become “When these products of oogenesis are instead…”

[Andy 10/24: Please make this change.]

In 7.2.2.4, right at the scroll flag Fertilization, the transition from the extant graphic and text needs to be a dissolve, not a blunt cut. Fade out the old and fade in the new. Furthermore, there is a flash frame during the transition showing the final graphic of two completed tables; the transition is supposed to go from the Non-disjunction in Meiosis II diagram with text smoothly to just the upper row of cells in the two-table graphic. After the transition, the tables are revealed by a downwards wipe animation.

[Andy 10/24: Soft fade out and hard cut in. I think Eric is asking for a slide transition of specific elements from one screen and the next. It’s a technique to mark the continuity of specific elements between screens. It would be cool but at this stage, it’s not necessary.]

[Andy 10/24: The transition must be under scroll bar control. Please correct this.]

If our new standard is to have the Interaction Instructions box open when the user arrives, we need to change the default position of this box to “open” in 7.2.4. Right now it is closed when I arrive.

[Andy 10/24: Please make this change. The default is to have it open then close after several seconds. There will be exceptions but let’s use this as the standard unless otherwise specified.]

In the exercise 7.2.3, there are no feedback sounds that help the user know when they have correctly or incorrectly dragged each set of chromosomes to the right cell. What happened to the scrape-sound (no good) and thunk-sound (good choice) that accompanied the previous version? Let’s get these back in.

[Andy 10/24: If you have sounds in the closet, let them out.]

Did we want a popup box that indicates to the user that they have successfully completed the exercise? How about a box that comes up saying “Good work! You have placed the correct chromosome combinations in the cells of Meiosis I.”

[Andy 10/24: Yes, when the exercise is complete, open a small window that says “This completes the exercise. Press the “Reset” button to try again. Then add a Reset button.]

The graphics of 7.2.4 are clearly distorted compared to a nearly identical layout from 7.2.3. The whole screen seems to have been drawn out horizontally. Let’s resize or adjust the cells and the draggable choices in 7.2.4 so that they look very similar to that of 7.2.4. The cell outlines should be round, not egg-shaped.

[Andy 10/24: The second exercise is distorted horizontally. Both exercises should be the same. My preference is for the wider version because it doesn’t have as much white space. It doesn’t matter if the cell outline is round or egg-shaped.]

We need the feedback sounds to be put back into 7.2.4 just like in 7.2.3. The user needs that scrape or thunk sound to track his progress. How about a “Good work!…..” popup, as in 7.2.3 which tells the user when he has successfully finished the exercise?

[Andy 10/24: Yes, please make these changes. Please review my earlier notes on this issue.]

“There is a rat in separation”, as my grammar teacher used to say. Fourth word of the first paragraph in the Conclusion, change “seperation” to “separation”.

[Andy 10/24: Please make this change.]

In the second paragraph of the Conclusion page, change the third word from “chrmatids” to “chromatids”.

[Andy 10/24: Please make this change.]

SecondPass Comments from Eric Stavney 11//04/03

Many of the changes we requested in FirstPass review were not implemented when I reviewed the animation. What happened on this one?
We lost the caption entirely from the graphic on the Introductory Page. We wanted to delete what was there and have it replaced by an html text of the same caption. Let’s get this back in please (see our first pass comments).

[Andy 11/5: I asked Murray to delete all of the labels and captions to expedite the revision process.]

The text in 7.2.2 scrolls rather slowly and needs to be sped up just a tad.

[Andy 10/24: It’s not optimal but we can live with the speed. No change required.]

The second sentence of the second paragraph in the scrolling text of 7.2.2.1 got the punctuation fixed at the expense of a new typo. Please delete the parenthesis just before the the word “Recall”.

[Andy 10/24: This is the second sentence after the “Normal Disjunction” flag.]

Towards the end of the Normal Disjunction scroll flag sequence of 7.2.2 the text fades out and nothing happens for a couple seconds until the graphic fades out a the second scroll flag of the segment. Let’s make the text fade coincide with the graphic fade and delete the dead time before the second scroll flag.

[Andy 10/24: Please make this change. The transition is too slow and the blank space is distracting.]