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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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Is collagen supplementation useless?

When collagen is digested is it broken up into usable components that the body can use to produce its own collagen? What evidence is there that supplementing with collagen type I & II etc.. can ...
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0answers
14 views

What is the correct answer? C or D [on hold]

Protein synthesis from amino acids by which structural component? Ribosomes or endoplasmic reticulum
3
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1answer
80 views

Cartilage regeneration

Why can we not regenerate cartilage in our ear and nose, while bones and flesh can heal? What makes it so resistant to regeneration. Can we artificially create it in the lab?
5
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1answer
2k views

Lifespan of connective tissue cells

This post is regarding a follow up on my initial post on "Properties and life cycle of chondrocytes and tenocytes". I am elaborating on my question on the lifespan of tenocytes and chondrocytes. ...
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0answers
19 views

What was the cause of some egg-laying animals evolution to animal-laying?

Is there a specific reason for this evolution? Are no egg-laying animals more complex beings so their embryonic development requires more time and better nutrition conditions?
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1answer
65 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 ...
8
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2answers
124 views

Can NSAIDs impact negatively the healing of tendons?

There are a number of articles regarding nonsteroidal anti-inflammatory drugs (NSAIDs) having a negative effect on healing conditions like tendonosis and tendinitis. From what I understand the ...
6
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1answer
376 views

Which cells are responsible for the extracellular matrix remodeling?

I am studying a case of tendinopathies induced by an alteration of how the extracellular matrix is being remodeled. From my understanding there has to be a careful balance of MMP (metallproteinases) ...
1
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1answer
31 views

Number of dopaminergic neurons in VTA

Do you know an authoritative source for the approximate number of dopaminergc cells in the ventral tegmental area (VTA)? Ideally I would like to know this for mice, rats, as well as humans, but one ...
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0answers
27 views

CELL BIOLOGY AND GENETICS [closed]

How the criteria of size, charge, polarity and hydrophilicity/hydropathy determine whether a molecule will pass through the membrane. The amino acid requirements of proteins and how they are placed ...
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0answers
35 views

Are formerly endosymbiotic organelles necessary for eukaryotes? If so, why? [closed]

It is widely known that the vast majority of eukaryotes have mitochondria, which are believed to have evolved from endosymbionts. The exceptions use related structures like hydrogenosomes which are ...
3
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0answers
23 views

Looking for realistic representation of angiosperm sperm cells during pollination

I've scoured Youtube, google, and a handful of my botany textbooks for a cellular-scale photo, animation, or video illustrating an angiosperm sperm cell during pollination/fertilization. ...
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0answers
15 views

Signals triggering ECM formation

What signaling triggers the formation by the cells of extracellular matrix ? I assume the mechanism is connected to autocrine signaling or paracrine signaling. Or maybe also stiffness sensing. Could ...
2
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2answers
69 views

Do histones constitute the largest proportion of the protein in chromosomes at mitosis?

Do histones contribute more (by mass) than non-histone proteins in the chromosomes formed during mitosis?
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1answer
56 views

What does “PDPN+ cells” means?

Are they podoplanin positive cells (cells that tested positive for podoplanin)? "...though it has been shown that podoplanin (PDPN+) cells analogous to mouse FRCs are found in human secondary ...
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0answers
8 views

Haemoglobinic acid

I’ve tried searching for the structure of haemoglobinic acid but it isn’t anywhere. I was trying to find out whether H+ ions bind onto the same site as carbon monoxide and oxygen on haemoglobin or not,...
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0answers
19 views

How is mRNA read by the ribosome? [closed]

I am aware that DNA is read in the 3' to 5' direction and then the resulting mRNA strand is created by the polymerase in the 5' to 3' direction. But during translation, which direction is the mRNA ...
2
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0answers
39 views

Why does K+ going out of the cell cause hyperpolarization?

I'm really confused by how the terms Hyperpolarization and Depolarization are used in Cell biology and hope somebody can enlighten me hopefully. Here's what they mean for me so far: Depolarization ...
1
vote
1answer
56 views

Why do many cells together survive better than one cell alone?

I know that one cell with no ECM is subject to anoikis. That's why in general one cell alone not in its environment is dying. But are there advantages for a cell to live close to other cells even of ...
1
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1answer
58 views

Does a cell suspend or exit cell cycle at G0?

In an exam, there was one question which asked whether the cell exits or suspends cell cycle at G0 phase. I answered that it exits cell cycle but the official answer key says it suspends cell cycle. ...
0
votes
1answer
9 views

Salt Bridge for Microbial Fuel Cell: Full or Partly Full?

I'm making a microbial fuel cell out of benthic mud and salt water in containers. My salt bridge will be made of agar and table salt solidified in PVC pipes. Does the salt bridge connecting the anode (...
3
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4answers
9k views

Are gametes diploid or haploid?

Some sources say that gametes are haploid, some say that they are diploid. I'm confused.
2
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4answers
1k views

The smaller the cell the greater its surface-to-volume ratio? [closed]

I read in a book that the smaller the cell the greater its surface-to-volume ratio (the surface area of a cell compared to its volume). And larger cells have limited surface area compared to its ...
6
votes
3answers
1k views

What is the main general difference between Mitosis and Meiosis?

I found such a clause: The general principle is that mitosis creates somatic cells and meiosis creates germ cells. However, I cannot agree. Each gametogonium needs to go through mitosis before ...
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0answers
26 views

Why did nature decide to make plasma membrane of animal cell hydrophobic?

I am taking Introductory Human physiology course on Coursera. The teacher said and I quote " the membrane of the cell is a hydrophobic barrier that prevents any charged ions or molecules from moving ...
2
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1answer
41 views

Are epigenetic modifications the most stable mechanisms for cell differentiation?

Wondering what the general take is on what are the molecular mechanisms that are mostly responsible for cell type differentiation stability; ie, for a cell's identity to actually become 'locked in' ...
13
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4answers
36k views

How fast do cancer cells divide (compared to normal cells)?

This question suggests that we have, on average, 50-70 billion cell divisions per day. I just read that cancer cells divide more often and are therefore more prone to radiation. I am wondering, for ...
24
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3answers
4k views

Are cells guaranteed to get at least one mitochondrion when they divide?

If mitochondria exist at random within a cell, isn't there a possibility that cell division will result in a daughter cell with no mitochondria? If not, what is the process for guaranteeing at least ...
0
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0answers
20 views

Can a lentivirus expressed protein that is undetectable by western blot be detected by BioID?

Cloned a single herpesviral gene into pCDH-EF!-GFP and see phenotypic effect on cells of interest and viral gene transcripts BUT unable to detect ANY protein using HRP boosted western blot. Even with ...
0
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0answers
19 views

What does it mean for a gametocyte to “reprogram” the genes inside of it?

I am aware that frequently clones have genetic defects not present in the donor organism, even though the two are genetically identical. The reason for this is that apparently the enclosing gametocyte ...
2
votes
1answer
75 views

Can radiation exposure cause cancer later in life even if no traces of radioactive material are present in the body anymore?

I had a long-lasting debate with a friend of mine about the Fukushima incident. The question that we tried to solve was if radiation or toxin exposure can cause cancer later in life even if no ...
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0answers
12 views

Insight on HPV vaccine to prevent/control reactivation of latent infections in those already infected

Some women experience reactivation of HPV infection in their 50's due to weakened immune system and weakened immune memory. Is it outside the realm of possibility that giving the HPV vaccine to those ...
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0answers
15 views

Very long cells besides neurons

In the human body single neurons can approach a meter in length. In other words the sciatic nerve is made up of (myelinated) axons, and each axon that runs from the spinal cord to the big toe is part ...
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0answers
46 views

Protein misfolding [closed]

Protein misfolding is usually prevented by molecular chaperons. Rarely, the chaperons are not able to prevent the misfolding as a result of which the infectous molecules called prions will form. My ...
1
vote
1answer
31 views

Can Phosphogycolate buildup in a plant kill it?

I'm trying to think of some things for the science fair, for part of my experiment I need to know if Phosphogycolate build up in a plant can kill it. Also, are there any chemicals that may disrupt the ...
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0answers
13 views

How are codocytes or target cells formed?

How are codocytes or target cells formed in conditions like Thalassemia? And why do they appear like a target(as in why is there a central red surrounded by pallor surrounded by red?)
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0answers
18 views

How do scientists genetically modify Interleukin for medical use, where do they source the gene and insert it?

I was wondering how scientists genetically modify Interleukin for medical use. Where do they source the gene from, what are the steps involved in genetically modifying Interleukin for medical use, how ...
0
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1answer
77 views

Fertilization of the human egg- where does our centrosome come from?

Is there a centrosome in a human egg cell? Is the reason why the egg cell remains paused before meiosis 2 because there isn't a centrosome, and it only divides when the sperm fertilizes it thus it can ...
2
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1answer
23 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 ...
0
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1answer
55 views

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. The trafficking of G protein coupled‐receptors (GPCRs) is one of the most exciting ...
2
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1answer
59 views

What does substrate mean?

I have been reading some literature on measurements related to biofilms. In some articles the word "substrate" seems to stand for the material on which a biofilm is growing. In other articles, it ...
2
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1answer
50 views

Why does a lightsource postpone the time it takes for the leaves falling from a birch tree?

It is autumn and the leaves have already left their trees on all birch and other trees that has leaves, except one. This birch has a spotlight pointed to the tree and it is on 24/7. I have recognized ...
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0answers
51 views

Stopping all intracellular activity in a reversible fashion

I have never studied biology but the following question seems meaningful to me. Suppose I take a cell, not that of a unicellular organism, but a human cell. Normally, there are some intracellular ...
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0answers
13 views

Endocytic pathway: Macropinocytosis

So I'm trying to understand this phrase: Unlike other endocytic pathways, macropinocytosis is acutely induced by growth factors From the following paper The 4 endocytic pathways I know of are ...
1
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1answer
40 views

Why is inhibition of inhibition (reciprocal inhibition) such a common motif in cell signalling?

In transcriptional regulation, you often find that positive signals proceed by inhibiting or destroying a protein that is in turn inhibiting or destroying the effector protein. This can be seen in the ...
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2answers
1k views

Can cysteine alone change pigmentation?

According to this graph (from here): cysteine contributes to pheomelanogenesis, and having a high enough concentration of cysteine makes the shift towards pheomelanin instead of eumelanin. So my ...
3
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4answers
276 views

How to find suitable qRTPCR reference gene for a inflammatory response experiment?

I have tried several housekeeping genes – Hprt, β-actin and GAPDH, to analyze the relative expression of a cytokine for measuring the inflammatory local response in mice ears. However, all ...
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1answer
70 views

Chargaff Rules (confusion) [closed]

A professor of mine wrote that: $\frac{A+T}{G+C}$ is constant in double stranded DNA of different origin. However The Chargaff rules state that due to base pairing in the DNA it holds that : $A=T$ ...
0
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1answer
62 views

Is all of the DNA used by genes (encoding DNA)?

My intuition tells me no, since only 1.5-2% consists of exons, so this statement would be wrong. The correct statement would have to be: only about 1.5-2% of the whole DNA is used by genes (encoding ...
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1answer
40 views

When do the first neurons appear in humans?

According to this Neural Plate The neural plate appears in day 18 in humans (very specific). and according to this Neural Plate (wiki) The progenitor cells that make up the precursors to neural ...