The study of cells: their physiological properties, structure, environmental interaction, division, life cycle, and death, as well as the organelles they contain. Also known as cytology.

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Is cell membrane living

We say cell wall is dead but nobody says cell membrane is dead. Is cell membrane living or dead ? If it is not dead then why is it not included in protoplasm : Protoplasm is the living contents ...
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Learning first-year biology + anatomy via documentary? [closed]

Probably going to take first-year biology in ~4 months; so was thinking to go through MIT's 7.00x on EdX… However seeing at how popular this topic is, I was thinking there might be a fun documentary ...
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47 views

Exotic Cell Shapes

As far as I know, plant cell shapes are a difficult thing to pin down. However plant cells have cell walls and so can be very rigid. However the only plant cells I've seen have been either block ...
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Ideal blood cell

I had been given an assignment to draw an ideal blood cell, a cell which can perform the functions of almost all the blood cells (like red blood cells, neutrophils, basophils, eosinophils and ...
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How is saltatory conduction faster than conduction of unmyelinated fibers? [duplicate]

It's always the same explanation that currents are able to "hop" along Ranvier nodes instead of passing continuously along the axon making saltatory conduction more efficient than continuous ...
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60 views

Termination of translation

What dissociates first - the last tRNA, mRNA and release factors or the subunits of ribosomes? I tried searching this from Lehninger but couldn't get a clean answer.
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132 views

Number of genes required to sustain life

Are there estimates of the minimum number of genes required to sustain life? In what I mean by life here, I don't include viruses.
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36 views

Fusion of neuron with a S phase cell

There was some experiment in which a S phase cell was fused with other cell and the other cell also began to replicate DNA. Would the same happen if fused with nerve cell ? Why or why not?
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52 views

Critical pO2 threshold for cell division?

I'm a physicist asking questions on an aspect of cellular metabolism, so excuse my biological ignorance! Hypoxia is a frequent complication of certain tumour types, and has quite an implication for ...
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36 views

Why must abortive transcription repeat itself a number of times?

Why must abortive transcription repeat itself a number of times before a stable DNA:RNA hybrid containing a transcript of 11 ribonucleotides is formed?
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106 views

How is it that the WI-38 cell line isolated by Hayflick in 1962 is still very much around and not affected by the 'Hayflick Limit'?

I have searched the net and I have not been able to come up with an clear answer. Edit: Here is the para quoted from Nature http://www.nature.com/news/medical-research-cell-division-1.13273 "So began ...
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1k views

Which human cells have the longest and shortest lifespan?

Which cells in a human have the longest lifespan? Which cell has the shortest lifespan?
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538 views

How does formaldehyde/PBS or methanol fixation of cells affect lysosomal pH?

The question is fairly simple - does formaldehyde or methanol fixation in preparation for immunocytochemistry/immunofluorescent staining affect the pH of the lysosomes? Some background: I'm trying to ...
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How did viruses learn to utilize the workings of a cell?

This is my first post here, so excuse me for its simplicity. Viruses can infiltrate a cell, overtake it and multiply. It has projecting fibers whose ends are shaped as kind of a "key" to a mobile ...
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538 views

Are mature RBCs prokaryotic?

Mature mammalian RBCs have all the characteristics of a eukaryotic cell except that they don't have a nucleus, they don't have any cell organelles. Does this mean that RBCs are classified as ...
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83 views

Why can't cell division happen the other way around?

Mitosis in eukaryotes happen in this order: DNA replicates and then the cell divides. Why doesn't it happen in reverse order (i.e., cell divides and then replicates the DNA)? I am talking about ...
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57 views

Is forced cell growth related to apoptosis?

Could an instance of forced cellular growth cause some cells to have their self-destruct mechanisms to malfunction or 'turn off'thus preventing apoptosis?
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311 views

How is the mRNA transported out of the endoplasmic reticulum?

In eukaryotes the nuclear envelope is continuous with the ER, so what helps it out of that?
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41 views

Domains in cell membrane

How is movement of proteins and lipids between different domains of cell membrane prevented? Why is the noncytosolic layer not able to do lateral movements between domains but cytosolic layer is able ...
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177 views

What is 'calcium conductance'?

What is the meaning of calcium conductance in ion channels. I encountered this in the following text: It was established that the µ and δ opioid receptors open potassium channels, which results ...
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46 views

Function of ER in reviewing mutated proteins

At least in the case of Cystic Fibrosis it happens that a mutant protein (which could actually function!) is held in the ER because the ER detects it as misfolded. Does this happen in every type of ...
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56 views

Why are fibroblast used so commonly in cell biology?

Fibroblasts are some of the most commonly used cells in cell biology. What are the properties of those cells which makes them commonly used ?
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96 views

Why are centrioles aligned at 90 degree with each other?

The centrioles are aligned at 90 degree with each other. What is the function of this?
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2k views

How do plant cell divide without centrioles?

Most plants do not have centrioles , so who does their function ?
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957 views

why is AUG the initiation codon?

Is there any reason why AUG is the initiation codon ? Why is there a need for an initiation codon ? Can't translation start with different codons?
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75 views

Do mitochondrial DNA have repair enzymes?

Mitochondria are considered endosymbionts originated from a prokaryote. So, do they have a DNA repair mechanism ?
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Generic Abbreviation for Immunopanning?

This is actually something I've been wondering for a while. I've seen all kinds of short hand used outside of papers (IPn most commonly), but in publications I've not seen an abbreviation for ...
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110 views

Suggestions for an experiment? [closed]

I would appreciate suggestions for my year-long AP Biology project. Such a project would consists of a standard experiment, to be done over the period of a year, so it would have >to be fairly ...
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Missing cells from immunopanning

Why do I not have any cells left in my positive panning plate after transferring from the negative panning plate during immunopanning? I am trying to purify retinal ganglion cells from postnatal rats ...
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117 views

Characteristics of life

If all of the characteristics of life are required for something to be defined as living, how can we account people or other life that can not reproduce?
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Method to inject genes into cells

The famous Hershey and Chase Experiment uses phages to inject genes into cells. In the beginning, Professor Yamanaka injected 24 types of genes into cells to figure out which genes turn a cell into ...
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155 views

Why did Fair Meiosis evolve?

How and why did Fair Meiosis evolve? I can hardly think that it provided a fitness advantage to the individual carrying the mutation. Why would it? Or did it evolve through lineage selection? Or was ...
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73 views

Randomness in living systems

The point of my question is not to talk about events that are uncontrolled by living organisms. My question is about controlled randomness, or I'd like to say adaptive random process. Process that are ...
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54 views

Cell state and cell function

I have read many papers that refer to cell type, cell state and cell function, but I haven't found an explicit definition for each of these terms. For example this paper (Brown et al. 1994. J General ...
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68 views

Botulinum Toxin

I asked on the cooking site, but was directed here. This is my original question http://cooking.stackexchange.com/questions/35726/botulinum-toxin-in-home-canned-green-beans The reading is quite ...
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56 views

The role of antibodies interacting with cancer

I'm learning about antibodies. As I understand it, antibodies detect stranger cells/bacterial/viruses by the molecules present in their membranes. In cancer cells, the cancer cell have produce some ...
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164 views

which exact mechanism triggers the first cell differentiation after n divisions?

I would like to understand which mechanism triggers the first cell differentiation after n divisions. I read previous articles on SE and Wikipedia articles on cellular differentiation and ...
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1k views

Why do cell membranes have a lipid bilayer?

Many cells have a cell membrane composed of two layers of lipids, why is it two layers and not just one? What purpose do the membranes serve?
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281 views

Beginning with centrifuge experiment

This is the first time I do a centrifuge experiment with my own centrifuge machine, it's just simple made by a rotor that can rotate the tube at high speed. As I know a centrifuge machine can be using ...
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112 views

Improving transformation efficiencies- induce supercoiling?

From my limited knowledge of science, I know transformation can be one of the hardest step in cloning, and that a large amount of research/trial and error has been done to improve on this step. I've ...
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413 views

How does ubiquitin recognize misfolded proteins?

Misfolded proteins are tagged by ubiquitin and then are destroyed by proteasomes. How does ubiquitin know which protein to tag?
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161 views

How can I create a microcapillary for manipulation of single cells?

i'm working as a diy bio. I'm finding a way to create a micro glass capillary for picking up single cells. I see this video on youtube and would like to know what is the minimum I/O diameter if I pull ...
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103 views

What do cells do when they aren't creating proteins?

I've always thought that the majority of the "work" in a cell is protein production, until I read the following. The Wikipedia article on the central dogma of molecular biology states this: 80% ...
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82 views

Coiling of chromatids during cell division

What is exactly coiling of chromosomes? I just heard about the names i.e paranemic, plectonemic, orthostichious, anorthospiral. I have ecaxtly no idea of what phenomenon is this. Also what type of ...
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646 views

fibroblast cells and fibers

I am interested in fibroblast cells in human arteries. Here are the things that I am not clear at the moment and I could not find any answer from the literature: What are the dimensions of these ...
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123 views

Can someone explain the color-changing unit (CCU) to me?

I've been physically carrying out serial tenfold dilutions on samples of Ureaplasma to work out the color-changing units (CCU). As a definition, the CCU is the highest dilution at which there is a ...
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48 views

Is every cell competent?

I would like to know if every cell is competent or if there are any cells that are not competent.
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65 views

Autophagy in eukaryotic cells

What is autophagy? How and under which circumstances is it used by the cell? I believe The reason for autophagy is some kind of recycling, am I right? But why does it occur in infections?
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Intracellular lipid transport

I know that lipids are carried around the body in the blood either as micelles or by lipid-binding proteins which allow them to be solved. Lipids can't always be integrated in a membrane though, the ...
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98 views

How do different tissue culture matrices affect background in fluorescent microscopy?

In response to my previous question, I've been reading up a little bit on poly-D-lysine, Collagen I, Collagen IV, laminin, and other tissue culture coatings that promote cell adhesion. I've always ...