Friday, December 21, 2012
Nortons Services
Together with our transportation service, did you know Nortons also offer the following nationwide services:-
dismantling and re-assembly of cabins, modular buildings and staircases
lifting, loading and transportation of your items
fully qualified Health & Safety appointed persons
maintenance of portable accommodation by fully qualified electricians, joiners and plumbers
storage facilities for portable accommodation with CCTV cameras and 24hr security
a wide range of hiab, low loaders and waggon and drag vehicles
plant and machinery movement
24 hour tyre call out service
Advantages of Portable Buildings
portable buildings are basically buildings that are manufactured in factories and the parts are shipped to the building site where they are assembled. portable buildings are not always portable once they're constructed, the only reason they're named this is because they're shipped to you.
Tuesday, November 13, 2012
Wednesday, October 17, 2012
Thursday, August 9, 2012
General Information and Links
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| Students on 2011 Costa Rica research trip take time out to zip-line the rain forest |
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| Working with Miami University students in Bahamas Tropical Marine Biology course |
This web site is designed for the use of those students in Mr. Gray’s biology classes and the parents of those students. Please check this site frequently for updates about activities and assignments.
Teaching Philosophy
I try to use a variety of presentation techniques to get across the content in the most interesting manner possible. Lectures are usually accompanied by PowerPoint presentations, numerous videos and even games in order to appeal to different learning styles. With the introduction of the one-to-one initiative, there will also be frequent "flipped classroom" activities. In the flipped classroom, students have the opportunity to work on teacher guided activities and assignments in the classroom while viewing and taking notes on video lectures for homework.
Biology is meant to be "Hands-On"
I try to use a variety of presentation techniques to get across the content in the most interesting manner possible. Lectures are usually accompanied by PowerPoint presentations, numerous videos and even games in order to appeal to different learning styles. With the introduction of the one-to-one initiative, there will also be frequent "flipped classroom" activities. In the flipped classroom, students have the opportunity to work on teacher guided activities and assignments in the classroom while viewing and taking notes on video lectures for homework.
Biology is meant to be "Hands-On"
I try to see to it that students have numerous laboratory and other types of activities to see the actual application of what they have learned in lecture and written about in assignments. Typically, students participate in hands-on activities once each week.
Biology is meant to be experienced outdoors
There should be high expectations
Biology is meant to be experienced outdoors
It is impossible to cover all aspects of biology in the survey courses offered in high school. The classroom also presents limited opportunities to see biology. I offer numerous field trips throughout the year to expand the students’ biological horizons. These include a variety of hikes to local sites such as Doe Run, Highlands Cemetery and the Loveland Bicycle Trail (photo). There are also trips to locations such as the Cincinnati Zoo, Cincinnati Natural History Museum, Krohn Conservatory and Newport Aquarium.
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| Students learn ecology on the Loveland Trail |
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| Mr. Gray participating in Cincinnati Museum dinosaur dig in Montana |
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| Raising chicks |
There should be high expectations
As an extension of the academic expectations placed by our parents in their homes we expect NDA girls to “be all that they can be.” It is expected that students will conduct themselves with common courtesy, good manners and integrity in the school. Students are expected to apply their best to all tests, assignments and projects in order to develop a sense of work ethic. In return, I offer a wide variety of opportunities for assessment including extra credit for field trips and retests so that students of varying abilities have the chance to succeed with the application of their best effort.
Wallabies (Zoology) - Week of November 12
Monday, November 12: Lecture and Video: Gastropods
Opportunity for a retest on Test #4
Tuesday, November 13: Completion of Lab #7: Phylum Molluska Part I
Procedure #2 Link
Procedure #3 Link
Procedure #4 Link
Procedure #5 Link
Procedure #6 Link
Procedure #9 Link
Wednesday, November 14: Lecture and video: Class Cephalopoda
Thursday, November 15: Lab #8: Phylum Molluska Part II
Friday, November 16: Study Hall due to Christian Awakening
Test #5 Tuesday, November 20
Bivalve VideoChapter 7 Phylum Molluska Notes
Chapter 6: Phylum Annelida notes
Zoology Rules and Policies
Zoology Syllabus
Tuesday, August 7, 2012
Scarlet Ibis (College Prep) Schedule Week of November 12
Opportunity for a retest on Test #4
Wednesday, November 14: Lab #10: DNA in the Kitchen
Extra Credit Video: "Lorenzo's Oil" 3 PM to 5:30 PM
Thursday, November 15: Lecture: RNA and Protein Synthesis
Friday, November 16: Activity: Protein Synthesis
Lab notebooks due next Monday, November 19th.
College Prep Syllabus
Monday, August 6, 2012
Platypus (Honors) Schedule - Week of November 12
Tuesday, November 13: Double Helix
Lab notebooks due
Wednesday, November 14: Quiz #4
Extra Credit Video: "Lorenzo's Oil" 3 PM to 5:30 PM
Thursday, November 15: Lab #10: DNA in the Kitchen
Friday, November 16: Lecture: RNA and Protein Synthesis
Meiosis Video
Lab #9: Mitosis
Platypus Fruit Fly Class Data
Honors Rules and Policies
Honors 1st Semester Syllabus
Wednesday, August 1, 2012
Fundamentals - Week of November 12
Monday, November 12: Lab #9: Northern Kentucky Fossils
Opportunity for retest on Test #4
Wednesday, November 14: Lab Work Day
Chapter 5 Video notes due
Chapter 5 Notes
Extra Credit Video: Apes to Man 3 PM to 5 PM
Thursday, November 15: Activity: Geologic Time Scale
Friday, November 16: Video: How the Earth Was Made
Lab notebooks due!
Quiz #5 next Tuesday, November 20th.
Test #4 Review
Dinosaur Armageddon
Dinosaur Extinction video
Lab #8: Relative Dating
What Happened to the Dinosaurs? (Narwhals) worksheet
What Happened to the Dinosaurs? (Zaglossus) worksheet
Lab #7: Recognizing Fossils
The Monsters Emerge
Chapter 4: Fossils and Paleontology
Fundamentals 1st Semester Syllabushttps://docs.google.com/a/ndapandas.org/open?id=0B5lgy1YcVS9nM1dMcVVMdERNSDA
Saturday, June 16, 2012
Moebius, Major Gruber, and Rusps (Rusps II /Archives V)
Click to enlarge; copyright Casterman 1995
Click to enlarge; copyright Casterman 1995
Click to enlarge; copyright Casterman 1995
Jean Giraud (also known as Moebius or Gir) died on March 10 this year. I first encountered his work in the seventies, probably in the magazine 'Métal Hurlant'. I do not think anyone disputes that he was a Grand Master of what the French call the Ninth Art ('Neuvième Art'): 'bandes dessinées', or 'comics'. You might that, regardless of his qualities, his work does not really belong here; while he did draw alien animals and plants, you could see that they were never meant to be realistic. The ones above prove that point, I think, while also underlining the facility with which he drew. To get another view of that, here is a YouTube take of him at work.
'
Click to enlarge; copyright holder unknown to me
The image above appeared on the cover of Métal Hurlant in 1976. Such images came as a welcome shock at the time. The way had perhaps been prepared by underground comics, but there still was else nothing like it; remember that science fiction films were not mainstream at all, and that computer-generated imagery was in fact science fiction. The cover impressed me so much that it stayed in memory to the present day. Major Gruber, the main character, just exudes character (stiff upper lip anyone?), as does his alien assistant. But look at that 'wall' behind him: it is part of the head of an animal slain by the 'great human hunter' Major Gruber. You cannot see the head well, partly because it is such a large animal, and partly because it is obscured by lettering, which does not hurt the design. This seems to be a magnificent example of telling a better story by not telling all of it.
So when does the major meet rusps? Well, he doesn't really, but just wait. Once rusps had evolved their imaginary existence, their place in the ecosystem required attention, so specialised armoured predators started ramming their way through the rusps' carapaces, keeping their heads tucked away below their bodies to avoid being blinded or decapitated by the rusp's whips. But after imagining this first onslaught, the question came up why rusps would stand still while attacked in this way? Could even a troupe of such predators bring a rusp to its many knees? Perhaps, but the losses to the predators would probably be unacceptable. An obvious solution would be to introduce a mega-predator, so large and strong that it could attack an adult rusp and expect to win. For reasons unclear to me I do not find that concept appealing; for now, adult rusps do not suffer from predation. But rusps die anyway, and a dead rusp constitutes a mountain of succulent meat.
Click to enlarge; copyright Gert van Dijk
Above is my first image of an animal working its way into a rusp carcass, at left. The right panel shows a specialised rusp predator, or perhaps a scavenger. It is not fast but very sturdy, and its two 'raptorial appendages' have developed into two different shapes. The left one is the prototypical blunt instrument, while the right is more useful as a scraper, to reach those parts where other scavengers cannot.
Click to enlarge; copyright Gert van Dijk
My sketchbooks show more versions of this particular scene, in between a variety of other topics. Here are three different versions from different periods. Do you see the influence of Moebius' scene in the back of my mind? The scavenger looks back towards the camera in the same way as the major looks into it. As for the dead rusp, I contemplated showing it as a wall of carapax over a tangle of collapsed legs, directly facing the camera; but would anyone understand what they were looking at? In Moebius' case, the wall was recognisable as a head. The three-quarter views represent moments where I thought I should provide more clues, while the straight-on views were more daring in this respect: the viewer would not know what kind of animal was dead here.
Click to enlarge; copyright Gert van Dijk
I later felt that perhaps the perspective of the predator was too complex. To see if I could improve on the sketches, I recently did a quick rough sculpt of such an animal in Sculptris (above).
Click to enlarge; copyright Gert van Dijk
I then imported the model into Vue Infinite (left), and exported the image into Painter 12 to paint over. Some very rough brush strokes indicate the structure and legs of the rusp. It is not too bad, but still definitely needs more work; perhaps the design works better on a square canvas. Once I feel that I can do the idea justice I will finally paint that scene, and I will be glad and than to have been inspired, as have many others, by Jean Giraud / Gir / Moebius.
Click to enlarge; from 'Faune de Mars'; copyright Moebius.
This is from a small book only available through Moebius' official site here.
This is from a small book only available through Moebius' official site here.
Monday, June 4, 2012
HW - 6/4/12
Tonight's homework is to read your group's article and then take detailed notes on it (these notes will be checked in class tomorrow). Below are some questions that will help you focus and format your notes.
o What is the writer’s issue/problem?
o How does the problem relate to what we learned about reproduction?
o What is Dr. Tatiana’s solution/advice?
o What are some other examples that Dr. Tatiana discusses?
o How does this issue/problem/mode of reproduction compare/contrast with human reproduction?
Saturday, June 2, 2012
The black, black grass of home...
Black? I hoped that by substituting 'green' with 'black' in the title of this evergreen ('everblack'?), your mind would create an image in which plants are suddenly no longer green but black. Plants hardly ever feature as more than background material in science fiction. SF artists may try to come up with odd plant shapes, but the general colour of your generic SF plant is green. Personally, I also often used green plants in my Furahan paintings without conscious thought.
What you see here are 'blackgrasses' on Furaha. In effect, they are largely brownish, but in this case at least I did not fall for the 'plants are green' trap. There are exceptions to ubiquitous greenery though, and the best-known one is probably Well's Martian 'red weed'. Anyway, perhaps it is time to think a bit harder about the colour of plants, first on Earth, then elsewhere. This post will be a bit technical; sorry for that. For more thoughts on this issue, see here and here.
The 'green, green grass of Earth' may trigger associations chlorophyll and photosynthesis ('chloro' means 'green' and 'phyll' is derived from 'leaf' in classical Greek, so it means 'green leaf stuff'). Photosynthesis concerns the trick of capturing the energy in light and transferring it to chemical energy (ATP), and chlorophyll is at the centre of that trick: it captures a photon, setting loose an electron that sets a cascade of motions going. As Chlorophyll is green, you might think that a green colour is good for photosynthesis. It is not: green light is almost useless for photosynthesis using chlorophyll.
Remember that what we call white light is a composite of a range of wavelengths in the electromagnetic spectrum, ranging from deep purple through blue, green, yellow and red to deep red. It is no coincidence that we call that portion 'visible light'. When light falls on an object some wavelengths are absorbed, while others are reflected. If an object looks green to us, that means that green light is reflected, meaning it is NOT used by photosynthesis. Above is an image of the absorption spectrum of two chlorophyll variants. A peak at a specific wavelength means that light at that wavelength is absorbed and used by chlorophyll. There are peaks in the red and blue parts of the spectrum, but not in the green portion of the spectrum. Does that matter? The answer depends on whether there is in fact a lot of light in that part of the spectrum, so let's compare the absorption spectrum of chlorophyll with the light output of the sun.
The atmosphere selectively absorbs some wavelengths, so what is relevant is how much of each wavelength reaches the Earth's surface. That is shown above. Try to find the visible part of the spectrum , from about 350 to 750 nanometer. You will see that there is a lot of light there.
Click to enlarge; from here
Here is a graph combining all the previous information. Note that the title states that chlorphyl is well-adapted to use solar energy. Well, yes, in the sense that it is roughly sensitive to light in the area where there is most energy. However, there is this big conspicuous gap, meaning that lots of light is unused by plants, mostly of the green variety. In fact, Earth plants would get on quite well if the sun did not emit all that energy at green wavelengths. (We would not like that though, as there would be about 40% less light to see with, and our ability to see details would be harmed as that depends to a large extent on green light; but that is another matter).
All this suggests that chlorophyll is not the best of all possible light absorbers on Earth. To make the most of sunlight, you would want a molecule that is responsive to a much broader part of the spectrum. Such a molecule would reflect very little light, so it would be black or at least very dark. You can also argue that, if chlorophyll can get away with using just part of the spectrum, so could another molecule. In fact, chlorophyll is not the only molecule used in photosynthesis.
'Bacteriorhodopsin' is a well-known example, occurring in some bacteria. Above is a graph in which its spectrum is overlaid on that of chlorophyll. This pigment has a rather broad absorption spectrum, but with a peak at precisely the spot where you would want it, meaning where the sun puts out much light: in the green / yellow parts of the spectrum. As a result, it looks reddish. There is a theory that these bacteria formed mats overlying the very first plants. The only light they let through was at wavelengths the bacteria did not use, so chlorophyll evolved to pick up just those wavelengths. This is a fascinating idea, but one thing that has me worried is the following: if chlorophyll could evolve such a detailed sensitivity to particular wavelengths, why did it stop evolving once plants outgrew those bacteria? Wouldn't it have made sense to retune it afterwards? If it would be sensitive to green light as well we would have black plants, and if it would be mostly responsive to green light plants would be purple.
I have no idea how easily evolution can tinker with light-sensitive molecules to shift their absorption spectrum. Still, light-sensitive pigments occur in vision as well as in photosynthesis, and there is an astonishing variety of pigments for colour vision in the animal kingdom. It seems that such pigments can evolve readily. But chlorophyll seems just to be sitting there, blind to all that glorious green light. Adding insult to injury, the chemical steps following chlorophyll are also singularly inefficient. Part of the problem seems to be that there is very little CO2 in the atmosphere, and that the molecule that takes in CO2 to strip the carbon from it leaving O2, quite readily works in the wrong direction, so the work is partly undone. After all this, the calculated efficiency of chlorophyll photosynthesis is on the order of 4-7%. Seeing how life on Earth depends on photosynthesis, that is a bit worrying.
In summary, the blindness of chlorophyll to green light suggests that other molecules with a different absorption spectrum could be just as efficient (or inefficient). It also suggests that you cannot tell the colour of plants well from the spectrum of the sun in their solar system. If you apply that reasoning on Earth, you will proclaim that Earth's plants are purple...
In order to show something besides graphs, I will show a nice image used on the cover of Scientific American. I found it on the website of the artist (Chris Webb) right here.
In another post I may go into the consequences of all this for alien plants. For now, just consider some parallel evolution going on, resulting in different groups of 'plants' using different pigments. Forests on such planets need not show shades of green only, but could sport a riot of colours. Ah! The green, blue, yellow, purple grass of home...
Click to enlarge; copyright Gert van Dijk
What you see here are 'blackgrasses' on Furaha. In effect, they are largely brownish, but in this case at least I did not fall for the 'plants are green' trap. There are exceptions to ubiquitous greenery though, and the best-known one is probably Well's Martian 'red weed'. Anyway, perhaps it is time to think a bit harder about the colour of plants, first on Earth, then elsewhere. This post will be a bit technical; sorry for that. For more thoughts on this issue, see here and here.
The 'green, green grass of Earth' may trigger associations chlorophyll and photosynthesis ('chloro' means 'green' and 'phyll' is derived from 'leaf' in classical Greek, so it means 'green leaf stuff'). Photosynthesis concerns the trick of capturing the energy in light and transferring it to chemical energy (ATP), and chlorophyll is at the centre of that trick: it captures a photon, setting loose an electron that sets a cascade of motions going. As Chlorophyll is green, you might think that a green colour is good for photosynthesis. It is not: green light is almost useless for photosynthesis using chlorophyll.
Click to enlarge; from Wikipedia
Remember that what we call white light is a composite of a range of wavelengths in the electromagnetic spectrum, ranging from deep purple through blue, green, yellow and red to deep red. It is no coincidence that we call that portion 'visible light'. When light falls on an object some wavelengths are absorbed, while others are reflected. If an object looks green to us, that means that green light is reflected, meaning it is NOT used by photosynthesis. Above is an image of the absorption spectrum of two chlorophyll variants. A peak at a specific wavelength means that light at that wavelength is absorbed and used by chlorophyll. There are peaks in the red and blue parts of the spectrum, but not in the green portion of the spectrum. Does that matter? The answer depends on whether there is in fact a lot of light in that part of the spectrum, so let's compare the absorption spectrum of chlorophyll with the light output of the sun.
Click to enlarge; from Wikipedia
The atmosphere selectively absorbs some wavelengths, so what is relevant is how much of each wavelength reaches the Earth's surface. That is shown above. Try to find the visible part of the spectrum , from about 350 to 750 nanometer. You will see that there is a lot of light there.
Click to enlarge; from hereHere is a graph combining all the previous information. Note that the title states that chlorphyl is well-adapted to use solar energy. Well, yes, in the sense that it is roughly sensitive to light in the area where there is most energy. However, there is this big conspicuous gap, meaning that lots of light is unused by plants, mostly of the green variety. In fact, Earth plants would get on quite well if the sun did not emit all that energy at green wavelengths. (We would not like that though, as there would be about 40% less light to see with, and our ability to see details would be harmed as that depends to a large extent on green light; but that is another matter).
All this suggests that chlorophyll is not the best of all possible light absorbers on Earth. To make the most of sunlight, you would want a molecule that is responsive to a much broader part of the spectrum. Such a molecule would reflect very little light, so it would be black or at least very dark. You can also argue that, if chlorophyll can get away with using just part of the spectrum, so could another molecule. In fact, chlorophyll is not the only molecule used in photosynthesis.
Click to enlarge; taken from this site
'Bacteriorhodopsin' is a well-known example, occurring in some bacteria. Above is a graph in which its spectrum is overlaid on that of chlorophyll. This pigment has a rather broad absorption spectrum, but with a peak at precisely the spot where you would want it, meaning where the sun puts out much light: in the green / yellow parts of the spectrum. As a result, it looks reddish. There is a theory that these bacteria formed mats overlying the very first plants. The only light they let through was at wavelengths the bacteria did not use, so chlorophyll evolved to pick up just those wavelengths. This is a fascinating idea, but one thing that has me worried is the following: if chlorophyll could evolve such a detailed sensitivity to particular wavelengths, why did it stop evolving once plants outgrew those bacteria? Wouldn't it have made sense to retune it afterwards? If it would be sensitive to green light as well we would have black plants, and if it would be mostly responsive to green light plants would be purple.
I have no idea how easily evolution can tinker with light-sensitive molecules to shift their absorption spectrum. Still, light-sensitive pigments occur in vision as well as in photosynthesis, and there is an astonishing variety of pigments for colour vision in the animal kingdom. It seems that such pigments can evolve readily. But chlorophyll seems just to be sitting there, blind to all that glorious green light. Adding insult to injury, the chemical steps following chlorophyll are also singularly inefficient. Part of the problem seems to be that there is very little CO2 in the atmosphere, and that the molecule that takes in CO2 to strip the carbon from it leaving O2, quite readily works in the wrong direction, so the work is partly undone. After all this, the calculated efficiency of chlorophyll photosynthesis is on the order of 4-7%. Seeing how life on Earth depends on photosynthesis, that is a bit worrying.
In summary, the blindness of chlorophyll to green light suggests that other molecules with a different absorption spectrum could be just as efficient (or inefficient). It also suggests that you cannot tell the colour of plants well from the spectrum of the sun in their solar system. If you apply that reasoning on Earth, you will proclaim that Earth's plants are purple...
click to enlarge; copyright Chris Webb or Scientific American
In order to show something besides graphs, I will show a nice image used on the cover of Scientific American. I found it on the website of the artist (Chris Webb) right here.
In another post I may go into the consequences of all this for alien plants. For now, just consider some parallel evolution going on, resulting in different groups of 'plants' using different pigments. Forests on such planets need not show shades of green only, but could sport a riot of colours. Ah! The green, blue, yellow, purple grass of home...
Friday, June 1, 2012
Extra Credit Field Trips
Click on this link to see available extra credit opportunities:
Look for an additional activity scheduled for November 14
Field Trips
Look for an additional activity scheduled for November 14
Field Trips
HW - 6/1/12
This weekend's homework is to complete Classwork 119. You need to read the letter below (Mr. Nice Is Mr. Frustrated in Mallacoota Bay) and then answer the associated questions. Assume that it is being turned in and graded.
HINT: It is helpful to search for images of the animals mentioned in the letter in order to get some context for the problem/solutions.
1. What is the writer’s (Mr. Nice) issue/problem?
2. What is Dr. Tatiana’s solution/advice?
3. How does the problem relate to reproduction, sexual selection, and/or genetics?
4. How does this issue/problem/mode of reproduction compare/contrast with human reproduction?
Thursday, May 31, 2012
HW - 5/31/12
Tonight's homework is to study for the quiz on reproduction tomorrow. Click on the link to access Classwork 118 if necessary.
Wednesday, May 30, 2012
Human Sexual Selection Resources
Why men tend to be more muscular?
Neurological basis for love?
"Sexual Selection in Humans" from Evolution: The Triumph of an Idea by Carl Zimmer
"Dating and Mating Pool" video
"Women Are Choosier" video
"Beauty of Symmetry" video
"Signals of the Flesh" video
"Attractive Man Funk?" video
"Love vs. Sex" video
Neurological basis for love?
"Sexual Selection in Humans" from Evolution: The Triumph of an Idea by Carl Zimmer
"Dating and Mating Pool" video
"Women Are Choosier" video
"Beauty of Symmetry" video
"Signals of the Flesh" video
"Attractive Man Funk?" video
"Love vs. Sex" video
HW - 5/30/12
Tonight's homework is to complete CW 117 (see below).
Classwork 117 - The Rules of Attraction?
Answer the following questions to the best of your ability in complete sentences on a separate sheet of paper. Assume that this is being collected and graded.
1. Review – What is sexual selection?
2. Does unconscious sexual selection take place in humans? Or do humans truly choose their partners? Or is it somewhere in the middle? Explain and support your answer. For example, feel free to discuss . . .
- Are human males and females looking for the same characteristics in a mate?
- Do they have the same reproductive goals?
- How does this question/topic relate to genetics or evolution?
Monday, May 28, 2012
Friday, May 25, 2012
An aside about rusp insides (Archives IVb)
This post is an additional one: having decided that rusps must have an endoskeleton, I started wondering what its structure might be, and here are some sketchy results.
In principle rusps have segmented bodies, just like Earths arthropods and vertebrates. But just like those animals on Earth, that basic structure is no longer visible in all aspects of their biology. In the rusp case the skeleton still shows strong evidence of segmentation. Each of the twelve pairs of legs should carry its own portion of the animal's weight, and the skeleton should reflect that. What you see above is one segment of the middle part of the body; the heads and whips are not shown. The legs are greenish in colour, and the beige ring is the main skeleton of the body. Note the two arched bones, situated directly above the hip joints. They meet in the middle high up near the animal's back. The mass of the animal is slung underneath these arches. There is a secondary arch in the belly of the animal acting as a sort of load-bearing floor. In the back a bone extends forwards and backwards, joining the segmental rings together in the form of a 'dorsal column'. The ensemble looks suspiciously like a vertebral column with ribs, but appearances are deceiving! In vertebrates, ribs are suspended from the vertebral column and do not transfer the weight of the animal to the legs. Instead, these rusp arches function exactly like arches in architecture, and transfer weight to the legs.
Here you see are twelve locomotor segments together. The sort of orange coloured bones at the sides provide another link between adjacent segments on the level of the hips. There is a joint in the middle, normally held in position by strong tendons,. Their purpose is explained in the next image. The skeleton of the anterior and posterior heads is not shown, and neither are the whip skeletons. However, you can easily imagine the dorsal column giving rise to the fore and aft whips.
Here is the animal bent sideways. The orange hinge bones at the sides are pulled together on ne side and extended on the other. I suppose the animal can flex more than this, but not really that much.
And finally another possibility. Here, the main weight-bearing structure is also a curved beam, but this one sits much lower in the body. The beam again supports a central column, that now gives rise to a vertical 'mast' supporting the body. The sides are linked in the same way as previously. I am less certain how to support the whips with this design; perhaps the central column simply rises up through the skulls to form the whip skeleton. Alernatively, it could find its origin in the top of the masts.
I haven't decided which design will be the final say on rusp anatomy, and in a certain sense it is not necessary to settle on a specific design, as not all of it is necessary to paint a rusp. Then again, thinking about what makes an animal work certainly will have its effect on a painting and is likely to add details. Those details do not serve to explain everything about an animal there is to know. Instead, they make viewers think that there is more than you can see. That work best if there really is more than meets the eye...
Click to enlarge; copyright Gert van Dijk
In principle rusps have segmented bodies, just like Earths arthropods and vertebrates. But just like those animals on Earth, that basic structure is no longer visible in all aspects of their biology. In the rusp case the skeleton still shows strong evidence of segmentation. Each of the twelve pairs of legs should carry its own portion of the animal's weight, and the skeleton should reflect that. What you see above is one segment of the middle part of the body; the heads and whips are not shown. The legs are greenish in colour, and the beige ring is the main skeleton of the body. Note the two arched bones, situated directly above the hip joints. They meet in the middle high up near the animal's back. The mass of the animal is slung underneath these arches. There is a secondary arch in the belly of the animal acting as a sort of load-bearing floor. In the back a bone extends forwards and backwards, joining the segmental rings together in the form of a 'dorsal column'. The ensemble looks suspiciously like a vertebral column with ribs, but appearances are deceiving! In vertebrates, ribs are suspended from the vertebral column and do not transfer the weight of the animal to the legs. Instead, these rusp arches function exactly like arches in architecture, and transfer weight to the legs.
Click to enlarge; copyright Gert van Dijk
Here you see are twelve locomotor segments together. The sort of orange coloured bones at the sides provide another link between adjacent segments on the level of the hips. There is a joint in the middle, normally held in position by strong tendons,. Their purpose is explained in the next image. The skeleton of the anterior and posterior heads is not shown, and neither are the whip skeletons. However, you can easily imagine the dorsal column giving rise to the fore and aft whips.
Click to enlarge; copyright Gert van Dijk
Here is the animal bent sideways. The orange hinge bones at the sides are pulled together on ne side and extended on the other. I suppose the animal can flex more than this, but not really that much.
Click to enlarge; copyright Gert van Dijk
And finally another possibility. Here, the main weight-bearing structure is also a curved beam, but this one sits much lower in the body. The beam again supports a central column, that now gives rise to a vertical 'mast' supporting the body. The sides are linked in the same way as previously. I am less certain how to support the whips with this design; perhaps the central column simply rises up through the skulls to form the whip skeleton. Alernatively, it could find its origin in the top of the masts.
I haven't decided which design will be the final say on rusp anatomy, and in a certain sense it is not necessary to settle on a specific design, as not all of it is necessary to paint a rusp. Then again, thinking about what makes an animal work certainly will have its effect on a painting and is likely to add details. Those details do not serve to explain everything about an animal there is to know. Instead, they make viewers think that there is more than you can see. That work best if there really is more than meets the eye...
HW - 5/25/12
This weekend's homework is to complete Classwork 116. See below.
Where Do Babies Come From?
Where do babies come from? Explain (in detail) how humans develop afterfertilization.
Be sure to describe and discuss specific structures, hormones, processes, etc. Think about methods used for the female reproductive system to meet its ultimate goal: producing healthy, unique offspring. Remember to try to connect your answer to other units in biology or the real world.
Thursday, May 24, 2012
Notes 49 – Fetal Development Part 2
Notes 49 – Fetal Development Part 2
As the embryo develops, membranes form around it. One of those membranes will project out and begin to grow into the wall of the uterus. The placenta begins to form during the 10th week. The placenta provides food and oxygen to the embryo/fetus while removing waste. Both the fetus and mother work to make it. Materials like oxygen, CO2, alcohol, waste, some viruses (HIV), antibodies, and drugs can pass through the placenta however the mother and fetus DO NOT share the same blood.
HW - 5/24/12
Tonight's homeworj is simply to prepare for tomorrow's Check-In on this week's notes and complete quiz corrections (if desired).
Wednesday, May 23, 2012
Notes 48 - Fertilization and Early Development through Mitosis
Fertilization is the joining of an egg and a sperm cell. It brings chromosomes from each parent together and restores the chromosome number back to normal. A fertilized egg is called a zygote.
After about a day, the first cell division through mitosis occurs. At day 3, the mass of cells (or embryo) enters uterus and is considered a morula or solid ball of cells. At day 5, the embryo is now a hollow ball of cells called a blastocyst.
How did you go from being one cell to a ball of hundreds of cells in just 5 days?
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