The most powerful approach to isolating a single mutant from a population of billions is positive selection.
Prior to therapy, a high PpIX fluorescence was observed in three patients; however, after iPDT, this fluorescence was entirely photobleached. These patients' viable tumor sections had high PpIX concentrations (mean PpIX uptake per tumor: 1.4-3.0 M).
<h3>Briefing:</h3>
However, no or just minimal PpIX uptake (0-0.6 M) could be seen in the remaining two cases. Strong PpIX uptake patients demonstrated therapeutic response and long-term clinical stabilization (no progression at 29, 30, and 36 months); the remaining two patients experienced early treatment failure (death after 3 and 9 months).
<h3>Describe fluorescence:</h3>
Two steps make up the chemical process of fluorescence first, a chemical fluorophore such a protein or carotenoid absorbs shorter-wavelength light (excitation), and then some of the absorbed energy is released as longer-wavelength light (emission).
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Answer: D. allopatric; breakdown
Explanation:
Allopatric speciation is a type of speciation whereby individuals of the same biological population becomes separated up to the extent that there will no longer be gene flow between them.
Answer:
A community
Explanation:
In ecology, a community is used to describe a group of organisms of different species populations that live and interact together at a particular time in a common habitat or ecosystem.
The two cardinals, colony of ants, a wasp’s nest, two squirrels, and the millions of bacteria represent a community of different organisms dwelling at the backyard tree.
<u>Answer:</u>
Mitochondria, the organelles involved in cellular respiration, can also generate chemicals called reactive oxygen species (ROSs). ROSs can damage mitochondria. Damaged mitochondria generate more ROSs than healthy mitochondria. This is an example of a positive feedback mechanism
The reactive oxygen species that are given out by the mitochondria during cellular respiration are the major cause of aging. Though this has a lot of negative effects but this also has a small amount of positive effects such as the start of angiogenesis or cell proliferation.
