Nathan R. Finney
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Artwork | Science Projects
Modern Physics Lab | R.E.M. Sleep Detector | Magnets | Biology

Science Projects [Biology]

The interactive modules shown on this page were deisgned and produced while taking "Bio 10: Introduction to Principles of Biology" and "Bio 49: Special Studies in Biology" at the Santa Rosa Junior College (SRJC) in 2004. For both projects I was advised by Abigail Zoger, instructor, Life Sciences Department, SRJC. To view the animations you will need to have the latest flash player installed.


 
Secondary Plant Growth (Press PLAY to Begin)
This interactive module illustrates a simple model for radial growth in plants.
Interactive Module Designed in Flash
SRJC, Spring 2004 (Updated Summer 2009)



The above animation was created to aid biology instructors in conveying radial growth in plants--a process that is sometimes difficult to visualize for students.

(1) After the instructor clicks "PLAY", the scientist cuts a cross section from the woody plant for students to observe. The cross section indicates the anatomy of the ring-like pattern resulting from secondary growth. Here the bark, sapwood and heartwood are characterized by their constituent materials (secondary phloem/cork cambium/cork, functioning secondary xylem tissue, and structural secondary xylem tissue respectively).

(2) To zoom in on the boundary between the secondary xylem and secondary phloem tissue the instructer clicks "NEXT". Once the animation zooms-in the instructor notes that the secondary xylem (yellow) and the secondary phloem (orange) cells are separated by the vascular cambium--a boundary comprised of undifferentiated cells. The instructor reminds the students that in this cross section we are looking down on the cells, so their significant length (relative to their diameter) is not shown here.

(3) The instructor clicks "PLAY" to show how the vascular cambium differentiates into xylem and phloem, pushing older cells away from the vascular cambium boundary.

(4) To show how this diffentiation effects the plant across its entire diameter, the instructor clicks "NEXT". The students are presented with the same basic cross section, this time viewed with some perspective showing the tube-like nature of the xylem and phloem cells. It should also be noted that in this toy model the xylem and phloem cells are much larger in diameter relative the the diameter of the vascular cambium in the previous cross section (where the curvature of the vascular cambium was not apparent). To advance the growth in the 3-D view the intructor clicks "PLAY", then "NEXT", then once more "NEXT". In this animation it becomes apparent that the vascular cambium differentiating into secondary xylem and phloem causes the diameter of the plant to increase.


 
Transpiration in Plants (Press PLAY to Begin)
This interactive module illustrates how plants can gather nutrients and water from the ground through transpiration.
Interactive Module Designed in Flash
SRJC, Fall 2004 (Updated Summer 2009)



The above animation was created to aid biology instructors in conveying simple water transport in plants through transpiration. Some students have a hard time picturing how the chain of water makes its way through the plant--this visualization is intended to help them learn a general overview of how water is pulled through the plant.

(1) After the instructor clicks "PLAY" the scientist cuts away the ground so that the students can see the root structure of the plant.

(2) To water the plant, the instructor clicks "NEXT". A cloud brings rain, which introduces moisture into the soil.

(3) To view the simplified model of transpiration the instructor clicks "NEXT". Here we see that due to cohesive and adhesive forces, the water will form a chain of molecules which is pulled up through the plant by relative differences in pressure and moisture between the soil and the air. Water that reaches the leafs of the plant is diffused into the surrounding air.

(4) To show how the plant can control this chain of water molecules (so that it doesn't lose too much moisture), the instructor clicks "NEXT". Here we see an anatomical break down of the leaf, as it relates to the overall sturcture in which the water travels. Right now the water is being held in by the stomata.

(5) To show what happens when the guard cells spread apart, the instructor clicks "PLAY". Without a boundary between the dry air and the wet leaf, the chain of water molecules responds to the hydrostatic pressure gradient by diffusing out of the open stomata into the surrounding atmosphere.

(6) To show what is happening with the chain of water molecules further down the plant, the instructor clicks "NEXT". Here the students see a simplified model of the interior anatomy of the stem, specifically relating to the paths formed by the different types of xylem through which the water molecule chain can travel. To show how the water molecule chain can flow laterally from column to column in trachied tissue, but cannot do so in vessels made of individual elements, the instructor clicks "PLAY".

(7) To show some of the finer details of water movement in the root of the plant, the instructor clicks "NEXT". Here the students are presented with a perspective view of a root, sliced to reveal the cross section. To show this cross section from above the instructor clicks "NEXT".

(8) Finally, the students are shown how water enters the root through the root hairs, then seeps through the various adjacent root tissues until it reaches the xylem where it will make its way up the plant and eventually out through the stomata. To show this in action the instructor clicks "PLAY".