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7

In short, yes, the definitions are still correct: The number of copies of a plasmid in the cell is determined by the mechanism of its replication: whether it is synchronized with the replication of the bacterial chromosome or is independent of it. In the first case, the initiation of replication is performed by the same mechanisms of replication of the ...


7

So, a quick biology lesson, going backwards. Proteins are the things that make up a good percentage of our cells (which make up a good percentage of us), and are the things that do the work of the cells - many are also known as "enzymes". Proteins are encoded by genes - while the saying that one gene codes for one protein is now known to be pretty inaccurate ...


6

Crystallography requires the collection of many measurements (could be a few thousand to even millions depending on the size of the molecule and complexity of the crystal (technically speaking, the size of the crystal's unit cell is a major determining factor for the size of the data set). I'm not going to assume this is a small molecule crystal like a salt ...


5

It seems like your question might contain two separate and linked issues, both of which are perhaps equally confusing and equally interesting. They're both really discussion questions in a sense, but they've also both been dealt with in the literature in thoughtful ways, so here's a stab at an "answer". Issue One: how does your species concept deal with ...


4

Spiders are part of a taxon called Arachnida. Arachnida also contain scorpions, Oppiliones, acari, … The science of arachnids is logically called Arachnology From wikipedia: Entomology (from Greek ἔντομος, entomos, "that which is cut in pieces or engraved/segmented", hence "insect"; and -λογία, -logia) is the scientific study of insects, a branch of ...


4

As can be inferred from the Shanks et al. paper linked in the question: In molecular biology, "suicide plasmid" is a term that refers to a plasmid which is replication incompetent.* Plasmids normally bear a sequence called "origin of replication" Ori which marks the plasmid for replication by the host cell. Plasmids that lack this Ori will not be replicated ...


4

According to my Henderson's Dictionary of Biological Terms, dry weight is The weight or mass of organic matter or soil after removal of water by heating to constant weight. So yes, your definition is correct and it is also applicable to cells. The dry weight of cells is the weight left when their water content has been removed by heating.


4

Since it was my edit of your question that started all this, I may as well weigh in. I will give a simplified version of genes and gene transcription, there are various details that make the process much more complicated than what I will describe but they are not relevant to the basic question here. First of all, as others have mentioned, genes are specific ...


3

As you point out, there isn't a singularly accepted biological defnition of 'hybrid.' The most basic would be a single organism that exhibits traits of two individual organisms, but that will find perfectly acceptable disagreement depending on who you talk to. You, for instance, are human - but a hybrid of your parents' genomes. So I would personally say ...


3

Just to clarify definitions, your genome is made up of sequences of DNA. DNA is constructed pairs of four nucleic acids, or nucleotides (A,G,T,C). That DNA has many loci within it, each codes for a gene. Loci are given gene names such as SHH (sonic hedgehog) which is part of a discipline called gene nomenclature. Humans have two versions of each gene, one ...


2

On-line means that's it's generally continuous, or constantly taking the measure, through a tube connecting the batch. Offline is used for things that are taken out of the reactor, or removed from the process. Thus it's "on" or "off" the system depending on whether it's contained within the normal piping/fludics of the system: "On" is in the system, ...


2

I think the definition in Wikipedia is simply bad because it depends on another debatable definition. I prefer something which follows from an observation made by Ricard Dawkins in The Extended Phenotype (the following is my definition, but I think Dawkins had something similar in mind): An organism is any system of components which depend on each other ...


2

The easiest way to understand this, in my opinion, is to think in social insects. In the ants, for example, there are polymorphisms, since the workers don't have the same phenotype as the queen or the soldiers. Also, one could argue that the whole colony is a massive metaorganism or superorganism, formed by the summation of all the individual ants. As in an ...


2

The term "cortical circuit" refers to the generalization that the neocortex is a uniform structure. For the most part, the outer sheet of the brain (the neocortex) is the same structure of neurons all the way around the brain. It consists of the canonical six layers and it generally looks something like this. Different research will emphasize different ...


2

I may be simplifying this, but I think it's just a fancy schmancy way of referring to the electrical "circuits" found in the brain, in this case the cortex (overall, or more specifically motor, visual, etc., as the case may be). Connectomics tries to map the connections between neurons, mainly in the brain, building what is, in some sense, a circuit. For ...


1

Based on your title and description, all that means is that in vertebrates the retina is inverted in a sense that light sensing cells sit at the back of the retina meaning light has to pass through layers of neurons and capillaries before reaching light sensing cells, whereas cephalopod has the photoreceptors at the front side of the retina, with processing ...


1

The term could mean two things depending on the emphasis: "developmentally programmed" would seem to emphasise the "programmed" nature of the development of something, implying that it is under specific regulation and the result of targeted energy expenditure ("Here, we describe widespread developmentally programmed nuclear destruction (PND) events that ...


1

I am not sure you can actually jump from a oak tree to an ape with whatever definition of species you're using. But this is some kind of practical implication of your question. The concept of species was already being used by Aristotle and was kept up to now although the grouping of living things into species might not be a clever thing to do. I don't think ...


1

One important difference is that spontaneous generation is a form of "mechanism" by which a certain species is "born", so it is repeated many times. For such complex organisms this would be part of their "life cycle". It would also need to be a regulated, robust process. Abiogenesis, on the other hand, would create an organism which from that point on does ...



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