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great mitochondria clip

Wed, 18 Nov 2009 01:52:46 GMT

clipped by: nessman
clipper's remarks: good for grd 11 biology

Metaphase chromatin and division

In the early stages of mitosis or meiosis (cell division), the chromatin strands become more and more condensed. They cease to function as accessible genetic material (transcription stops) and become a compact transportable form. This compact form makes the individual chromosomes visible, and they form the classic four arm structure, a pair of sister chromatids attach to each other at the centromere. The shorter arms are called p arms (from the French petit, small) and the longer arms are called q arms (q follows p in the Latin alphabet). This is the only natural context in which individual chromosomes are visible with an optical microscope.

Tags: mitochondria

Phycomyces blakesleeanus sporangiophore

Tue, 17 Nov 2009 00:01:02 GMT

clipped by: nessman
clipper's remarks: isn't it pretty?

Clip Source: bio-ditrl.sunsite.ualberta.ca

Title: Phycomyces blakesleeanus sporangiophore

Description: A section of the growing zone of stageIV sporangiophore of Phycomyces blakesleeanus showing mitochondria, microbodies, tubular endoplasmic reticulum, lipid globules etc: Magnification x65,000 EM lab., Biological Sciences, U.of Alberta, Edmonton, AB. section and photo by R.Bhatnagar

Tags: mitochondria

Metaphase Chromatin & Division

Mon, 16 Nov 2009 22:05:17 GMT

clipped by: nessman
clipper's remarks: really useful stuff

Clip Source: en.wikiversity.org

Metaphase chromatin and division

Human chromosomes during metaphase.

Tags: mitochondria

Out of Phase Signals

Fri, 03 Jul 2009 18:18:58 GMT

clipped by: nessman

Clip Source: cnx.org

Out of Phase Signals As Seen by a 3-Microphone Array

Figure 2

In order to determine the direction of origin of a signal, we have to add a time delay to the recorded signal from microphone that is equal and opposite of the delay caused by the extra travel time. That will result in signals that are perfectly in-phase with each other. Summing these in-phase signals will result in constructive interference that will amplify the result by the number of microphones in the array. The question is how to know what time delay to add that will produce the desired constructive interference. The only solution is to iteritively test time delays for all possible directions. If the guess is wrong, the signal will destructively interfere resulting in an diminished output signal, but the correct guess will result in the signal amplification described above.