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A typical animal cell has 1000-2000 mitochondria. From a statistical point of view, assuming a random distribution of the mitochondria and that the cell splits in half, the probability of having 0 mitochondria is (1/2)^1000 or 9e-302. This makes it an impossibility for all practical purposes. With enough mitochondria, a process to ensure the cell splits ...


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In addition to S Pr's excellent example, I wanted to point out that some very recent research describes some special behavior in oocyte development specifically related to mitochondria selection. Here's a easy-to-read version: https://www.sciencedaily.com/releases/2019/05/190515131741.htm Specifically, during meiosis, the oocyte specifically "puts the ...


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Isn't there a possibility that cell division will result in a daughter cell with no mitochondria? Yes, there is always the possibility. However, there must be a strong negative selection pressure against eukaryotic life that cannot achieve the proper partitioning of mitochondria, so you can imagine that there are mechanisms in place to prevent this case. ...


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The center of the cell in this case is a way to say "the nutrients arrive to every part of the cell", and should not really be taken literally as "the center". If the cell is modeled as a sphere, with the nutrients diffusing in from the outside, the whole sphere would be filled with nutrients when the nutrients "arrive to the center". Figure 1 shows how the ...


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It's to do with the chemistry taking place in the system, and then in turn the balance of energy resources. Leaves contain chlorophyll, a molecule that traps light energy. It is large molecule containing a long carbon chain and a magnesium atom surrounded by 4 nitrogen atoms. In terms of a plants energy resources it is an 'expensive' molecule, but it is ...


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A substrate is an underlying substance or layer, or less strictly, the medium within or upon which an organism grows. For instance, you can have a filamentous fungus grow on a solid medium (e.g. on an agar plate) or in liquid medium (e.g. in a shaken flask containing a solution) and its substrate would be the contents of the agar or solution. It's nothing ...


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I know this question is old, but I doubt the pheomelanin switch could be made orally since most nutrients cannot survive the process of digestion; it would take a lot of cysteine/glutathione to do so. From my light research, you may also need other ingredients in this hypothetical pill like sulfur (MSM, same thing in joint supplements).


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Finding a suitable reference gene is tricky. It depends on your prior knowledge about the system. You may start with the same amount of RNA but errors can accumulate many other steps. That is why you use a reference gene to minimize the effect of those errors accumulated during sample processing. So unless you are very precise, you cannot say that everything ...


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If you are asking if histone mass represents a larger percentage of total chromosome mass then the answer is yes when considered at the level of the nucleosome. Each histone-octamer wraps ~147 base pairs of dna around 1.7 turns. The histone-octamer consists of two copies of each of the four structural core proteins (H2A, H2B, H3 and H4). The sequence ...


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Context is important. A/T == 1 and G/C == 1 (approximately, to within a measurement error) are Chargaff's rules for double-stranded DNA, occurring because A pairs with T and G pairs with C. (A+T)/(G+C), or (G+C)/(A+T+G+C), are completely different ratios unrelated to Chargaff's rules. These are roughly constant across individuals for a given species and ...


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The ENCODE consortium classifies human and mouse genome elements to try to answer this very question. Work by ENCODE suggested up to 80% of the genome is functional in some way. In other words, by that upper-bound measurement, there is apparently more to DNA's role in biology than just encoding genes — there's a lot going on under the hood. Case for ...


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Apparently, olfactory axons and GnRH producing neurons are among the first neurons that migrate from neural crest at around 39th day of gestation in humans (Cassoni et al., 2016). In rodents, early GnRH neurons migrate together with a heterogeneous coalescence of placode-derived and neural crest-derived migratory cells (Forni et al., 2011) and ...


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I don't think there is a single "class of graph" that isn't used in biology. In biology (just like in any other natural science), we have all kind of data types; non-ordinal variables boolean ordinal categorical numeric tree data other types of network data pure functions (from statistical or theoretical models) pictures sounds etc.. We make all kind of ...


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