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Questions tagged [cell-biology]

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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Length of cell cycle dependancy on nutrients, pressure, temperature or other factors

How is the duration of cell cycle influenced by the concentration in nutrients, mechanical constraint, temperature or other factors ? And can it change strongly ? Meaning there are 2 possibilities, ...
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36 views

Does the molecular composition of human body change after a period of time?

I was discussing change in human biology over time and my two in-laws charged in saying, "we're molecularly different after x". I didn't pay attention to what time period they exactly mentioned (hence ...
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Using high risk pregancy to advantage [on hold]

If a woman over 40 having a child with increased risk of the child having down syndrome decrease the chance of that child developing cancer later in life?
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Pits, symplastic or apoplastic pathway?

After water has moved through the endodermis through the Casparian Strip, water continues to move down the water potential gradient into the xylem vessels through the pits, is movement through the ...
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Where do the oxygen bound in glucose vs the atmospheric oxygen go in cellular respiration?

I know that water is produced during glycolysis and oxidative phosphorylation and that carbon dioxide is produced during pyruvate oxidation and the Kreb Cycle. However, I'm not sure where the oxygen ...
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What is the segregation pattern from this cross? [closed]

I would like to know how to properly do the cross between these genotypes. I don't exactly how the AaBbCc produces 8 gametes and the AabbCc Produces 4 gametes I do understand if we multiply both ...
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How to compute the expected number of base pairs in the telomere after a number of mitotic divisions? [closed]

One of the chromosomes in a nucleus has a telomere which contains many repeats of the base sequence TTAGGG. This chromosome was extracted from four different cells and the total number of bases in the ...
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36 views

Does digestion require hydrochloric acid?

Would our digestion function any differently if we secreted something else, like sulfuric or nitric acid, instead? I'd assume an acidic environment may be required, but not sure if chloride is also ...
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1answer
27 views

How does the zygote divide much faster than other cells?

Normally a cell has a mechanism that controls its division. As far as I know, it checks surface area and stuff like that to decide to go for mitosis or not. However, this is not the case for a zygote....
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What are the (evolutionary) advantages of secondary transport?

Secondary active transport uses electrochemical gradients as a source of energy for the uphill transport of substrates (coupled to downhill transport of the ion). However except for in a few cases (e....
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1answer
18 views

Exocytosis of synaptic vesicles

I'm reading the following paper: http://jcs.biologists.org/content/123/6/819 The part I am really confused about is when they say: Exocytosis appears to use two alternative pathways: clathrin-...
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Spatially Encoded GPCRs?

I'm reading this paper, and I'm already lost in terms of what they mean by GPCR signaling is spatially encoded. How can signaling be spatially encoded?
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2answers
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What is a “pan-specific” antibody?

I am new to biology. I searched a lot to find an article that explains what "pan-specific" antibody is but I could not find anything substantial that would help me understand what it is. An example ...
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Rhodamine 123 Staining Function

How does Rhodamine 123 act as a probe for Mitochondrial Staining? What is the Exact Biochemical Basis? and can it Stain Chloroplast as well? Thanks in Advance
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1answer
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Lysosomal Storage Disease

In my biochemistry class today we did a problem detailing two lysosomal storage diseases. In the first scenario, a cell line for I-cell disease can synthesize lysosomal hydrolases that are perfectly ...
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What is the mechanism behind cells being arrested in G0 phase by serum starvation?

When Dolly was cloned, it was not from a totipotent cell in an early embryo but a G0 phase induced cell originating from the donor sheep's mammary glands. I have found sources stating that a fully ...
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Difference in timescale of tissue movement vs cellular differentiation

I would like to better understand the difference in the timescales that cells seem to function. For example, how is it that muscle cells can move within seconds or less under stimuli such as hormones ...
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How can I learn biology by myself? [duplicate]

I am only 15 years old,and my primary school education hasn't been that good,also I forgot a lot of things. I would like to start again,and I am asking for your advice. What are some of the good ...
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Why are Barr Bodies usually seen along the edge of the nucleus under the light microscope?

We do a typical class exercise of aceto-orsein staining of buccal epithelial cells from female students to visualize Barr bodies under the light microscope. All the illustrations and pictures in the ...
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Examples of GDP (rather than GTP) activating cell signalling?

Is there any known example in a cell where a protein is activated by the hydrolysis of GTP to GDP, rather than the reverse in which a protein is activated when GTP binds to an inactive GDP-bound ...
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Are there only a few alleles or groups of many alleles impacting protein structure and function?

I'm in the first year of Medicine and I'm studying Genetics and Evolution. I have this doubt in the back of my mind and I'm not being able to move forward without someone explaining me what's wrong ...
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1answer
32 views

How are primary monoclonal antibodies for screening mutant cells made, physically?

I'm working with a fairly common protein expressed in a large numbers of organisms, let's say a keratin-associated beta-protein. I'm trying to develop a process which requires primary-secondary ...
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0answers
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What regulates cyclic AMP?

After reading a textbook chapter on GPCRs I am still confused by what regulates cAMP. I took in my notes that cAMP is made by adenylyl cyclase and destroyed by cAMP phosphodiesterases (also another ...
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Is homocysteine converted to glutathione during oxidative stress?

From the paper titled "The basis for folinic acid treatment in neuro-psychiatric disorders" by Ramaekers et al., 2016: On the left side of the figure, the purine metabolite GTP serves as the ...
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What is the structure of DNA during Interphase? Chromatin Fibre or Beads on a string(nucleosomes)?

During Interphase, does DNA predominantly exist as Chromatin Fibre (30nm fibre) or Chromatin/beads on a string structure(10nm) ?
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1answer
65 views

How do viral vaccines work?

I have read that a vaccine against a pathogen typically works by using a dead or weakened version of that pathogen and then inciting an immune response against the pathogen so that the immune system ...
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1answer
46 views

What do the text annotations in an electron micrograph mean?

I saw a photograph taken from an electron microscope, with some text. I want to know what is the meaning of these numbers and letters? Thank you! Regards.
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Dental follicle cells

Are dental follicle progenitor cells and dental follicle precursor cells the same cells or they are two different cell types? Thank you.
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1answer
105 views

Is Protein-to-DNA ratio a good estimate of cell size?

I need help interpreting the result of an experiment. My class performed an experiment measuring protein concentration between heart, liver, and kidney tissue samples. The results were: Heart: 4.714 ...
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1answer
32 views

Approximate Cell Doubling Time?

If I know it takes 12 min to occur in mitotic fibroblast cells and I count there are 32 dividing cells in the microscope slide out of a total population of 32034 cells, how do I calculate the ...
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1answer
33 views

Why do stem cells injected into muscle become muscle cells?

In this article published in Science Daily, researchers injected teratoma-derived stem cells into mice with muscular dystrophy, and the stem cells regenerated 80% of the lost muscle. But what is the ...
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1answer
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Is there any independent non-DNA based information system in the cell

The information in protein is not neccessarily independent of the genome as the information of amino-acid sequence comes directly from the genome. The process of post-translational modification may ...
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Electron Transport Chain Proton Pumping into the Intermembrane Space

In regards to the electron transport chain, I know that complex I pumps 4 H+, complex III pumps 4 H+, and complex IV pumps 2 H+, but where do these numbers come from? If someone could explain this, ...
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1answer
34 views

Where do the lysines come from during ubiquitination?

I know that Ub forms an isopeptide bond with lysine, but where do the lysine come from? Are they just always available for the Ub to find to during the ubiquitination process? Is there a free lysine ...
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1answer
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How many phosphates are in the 5' end of a DNA strand?

I know that the pyrophosphate of a NTP is hydrolysed so that it can create enough energy for the synthesis of DNA. But if we want to get specific we can know for sure that the 3' end of the DNA strand ...
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Can an importin without any cargo pass through the NPC?

Can an importin (nuclear import receptor) without any cargo pass through the Nuclear Pore Complex (NPC)? If it can, wouldn't it be a waste of energy to have the 'unloaded' importin enter the nucleus ...
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What proteins are assisted by chaperone folding?

I've been looking into a lot of papers, and most say that chaperones assisted in the folding of misfolded proteins, or Ubiquitin markers aggregates for degradation by the proteasome. Or it will say ...
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1answer
33 views

How do you dilute forward and reverse primers for a master mix?

I apologize for the very naive question, but I'm just starting out in a high school biology lab and I am very confused. If I have stocks of 100μM for forward and reverse primers separately, I can ...
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0answers
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True or False: Endocytosis delivers vesicles directly to the cis face of the Golgi complex

Does anyone know the answer to this question, and also the explanation of to why this is True or False? I know that Endocytosis is the process of uptake of materials into cells including ...
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2answers
61 views

3D Cellular Model

I'm learning biology on my own and it's pretty hard to understand all processes inside a cell from the side of chemistry and physics and in some cases pointless to bring a complexity instead of ...
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Is it possible to remove cyanobacteria from rainwater without killing it?

My collected rainwater has a pronounced blue-green tint. I presume that this is due to the presence of Microcystis or another planktonic cyanobacterium. Is there a way to remove the cyanobacteria from ...
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3answers
156 views

Does sex-chromosomes exist in all the cells in a human body? [closed]

Each cell of a human body contains 46 chromosomes. So every cell must contain a pair of sex-chromosome. Is it true? Then a cell of a male and a cell of a female are always different and never be the ...
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Diffusion to center of the cell

I have been researching about the ratio between cell membrane surface area and volume. Obviously, when the volume increases faster than the surface area, and up to a certain point, there is ...
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How do scientists determine the nature of ions passing through a channel/carrier/pump?

The NCE (Sodium Calcium Exchanger) transports 3 Na+ inside the cell for 1 Ca2+ outside. How did we figure this out, and other mechanisms of this sort? If it were a protein, we could tag it with GFP. ...
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How would you use PGAl to select for mutants of beta galcodosidase gene (z-) and permease (y-)?

How would you use PGAl to select mutants of beta galcodosidase gene (z-) and permease (y-)? Or do you just use PGAL to grow these mutants after you've isolated the mutant gene and inserted it into a ...
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1answer
27 views

Do all cells of a plant contain chloroplasts? [closed]

If the answer is no, then how do plant cells tell whether they need to keep chloroplasts or not? What kind of signals are used, and how are chloroplasts eliminated?
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1answer
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Can PCR detect phosphorylated protein? [closed]

I'm trying to detect the level transcriptional protein inside cells. However, the cells contained both of this protein that is phosphorylated and not phosphorylated. Can RT-PCR detected the level of ...
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0answers
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What's inside the perinuclear space?

The cell proper contains the cytoplasm in general and the cytosol in particular when referring to the fluid/gel without notable organelle. Once we move inside the nucleus there is the nucleoplasm and ...
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Chemical composition of human nucleoplasm?

I'm working on a computer visualisation of the inside of a human cell nucleus (embryonic stem cell for now if it makes a difference) and want a good approximation of the chemical composition of the ...
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1answer
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Lobed Nuclei still count as One nucleus?

Do the Lobed Nuclei of immune cells (such as Megakaryocytes) still count as one nucleus?