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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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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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DNA Existing Outside Cells

What is the ideal conditions for the existence of DNA (pH, nutrients, etc), and where is this medium found to naturally occur outside of cells?
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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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1answer
107 views

Difference between morphogens and evocators in development?

I am specifically interested in this within the context of 1950's developmental biology (I presume the meaning and scope of usage of the terms has changed since then), as I am reading Alan Turing's ...
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1answer
101 views

What is the difference between a signal peptide and a transit peptide?

From what I know, the two names are used interchangeably and I haven't found any resource which says otherwise either. Is there at all any difference, is there a transit peptide that is not a signal ...
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1answer
27 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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2answers
156 views

How do cells relocate transmembrane proteins from one side of the cell to the other? Is it possible?

Is there a process by which cells can relocate proteins residing on the cell membrane in areas of low demand to that of a high demand location somewhere else in on the cell? What's that process called?...
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0answers
30 views

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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302 views

Is a microspore diploid?

In gymnosperms the plant body is predominantly sporophytic. It produces microspores or megaspores my textbook says that these undergo reduction division in order to form male gametophytes pollen ...
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0answers
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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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Difference between pili, fimbrae, cilia and flagella

What is the fundamental difference between all these extensions? What are their primary functions? Why did these different structures evolve -- wasn't it possible to have just a single type of ...
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1answer
113 views

What is the advantage of not having cytokinesis after karyokinesis?

In nature most of the cells are mononucleated, but in some cases like osteoclasts, umbrella cells of transitional epithelium, tapetal cells of another etc. are multinucleated. Wikipedia article about ...
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1answer
288 views

How is energy acquired from ATP? [duplicate]

How is energy acquired from ATP (i.e. What is the energy-releasing equation involving ATP plus water)? I Would be grateful for the answer.
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1answer
12k views

How do red blood cells survive without a nucleus?

I was reading this question Why do mammalian red blood cells lack a nucleus? According to my understanding, a nucleus is the cell's control center (like the brain). All the functions in the cell are ...
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1answer
1k views

Where does an organism store reserves of amino acids?

Where does an organism store reserves of the amino acids it needs to build various proteins it needs: in the liver? in the blood? in every cell?
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1answer
808 views

Has anyone used Crispr/Cas to induce a knock-in in MEF cells?

Does anyone have experience with the CRISPR/CAS9 platform performed on MEF? Or does anyone recall any relevant articles?
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1answer
206 views

Comparison between Transmission Electron Microscope (TEM) to Scanning Electron Microscope (SEM)

Can someone state the advantages of Transmission Electron Microscope (TEM) over Scanning Electron Microscope (SEM) and vice versa?
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0answers
11 views

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
58 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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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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1answer
90 views

What determines the metabolic pathways that a biological cell is able to carry?

For example: human cells (eukaryotes) can utilize the Krebs cycle pathway to generate more ATP after glycolysis, but most bacteria cannot utilise the Krebs cycle plant cells can utilise the Calvin'...
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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
79 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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2answers
419 views

Chromosomal pair possible in metaphase - I

There is this question which was asked in my exam. A diploid cell contain 6 chromosomes. How many possible random arrangement of homologous chromosomes could occur during metaphase-I? (consider ...
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1answer
22 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
21 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
31 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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0answers
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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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0answers
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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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0answers
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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
31 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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1answer
273 views

What is the role of lamellar bodies in lung cells?

Lamellar bodies have been found to be secreted in lung cells many of their associated proteins have been identified. What is the current consensus or research on the function that these lamellar ...
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2answers
60 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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0answers
53 views

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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3answers
118 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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0answers
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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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1answer
50 views

Is it possible to fuse DNA from two sperms into one sperm?

Is it possible to fuse the DNA of two genetically different sperms into one singular sperm? In theory, half of the number of chromosomes in a normal sperm would come from one sperm and the other half ...
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0answers
15 views

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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3answers
102 views

Evolution question on speciation? Really confusing!

Okay, my teacher assigned this homework question, but nothing like this was ever given in our textbook. Suppose that a type of tree tends to speciate over 10 million years and a species of fly tends ...
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0answers
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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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0answers
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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
34 views

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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1answer
12k views

What organelles are in an onion cell?

I was wondering what organelles are in an onion cell, because, based on the labs we are doing in my biology class, I only saw a nucleus and cell wall. My friends and brother say there are all the ...
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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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1answer
43 views

Lobed Nuclei still count as One nucleus?

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