Tutor profile: Adit S.
Subject: SAT II Biology E/M
Mitochondria are cell organelles that are common amongst almost all eukaryotic cells. However, upon analysis of mitochondrial DNA (mDNA), their sequence appears closer to prokaryotes than that of eukaryotes. Why (i.e. what is the prevailing biological theory that explains this)?
Endosymbiotic theory. Mitochondria have circular DNA like prokaryotes, distinct from eukaryotic linear DNA. Mitochondria can also self replicate. Endosymbiotic theory states that mitochondria were prokaryotic cells that were engulfed ("eaten") by eukaryotic cells due to their energy/ATP-creating capabilities. Thus, though they were a part of the eukaryotic cells, they retained some of their prokaryotic traits (circular DNA, self-replication).
Subject: Basic Math
3x - 6 = x + y + 1 Find the slope and y-intercept of the line above.
3x - 6 = x + y + 1 2x - 7 = y slope = 2 y-int. = -7
Many species undergo radical changes to transition between a larval phase and an adult phase. For example, tadpole to frog, caterpillar to butterfly, etc. Ecologically thinking, why is this more beneficial than NOT undergoing radical changes and simply growing normally (like most mammals)?
Larvae that are radically different from adults of the species will require a different environment to prosper, including different predators and an entirely different diet. This means that the larvae will occupy a different niche than the adults of the species, thereby providing LESS competition with adults for resources. Less competition gives more room for both the larvae and the adults of the species to prosper.
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