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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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How does hydrophilic and/or hydrophobic components of polysaccharides influence their 3 dimensional conformation?

It is my understanding that polysaccharides are insoluble in water. Does this mean they are hydrophobic? Beyond being insoluble in water how does this affect their 3D structure? Thanks!
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do platelets cytoplasm contains DNA?

I'm a 12th-grade student and I have an entrance exam this year. I have a question in biology. I would appreciate you if you help me <3 as we thoroughly know platelets are multiple pieces of a big ...
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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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Why sperms don't forms follicles

As all of us know that in meiosis oocyte forms follicles and egg cells, so my question is that if an oocyte can form follicles then why sperm cells do not forms the follicles? And in evolutionary ...
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stem cells divisions and normal cells division

I'm a beginner in biology, but I've read that stem cells replace the "worn out" cells or the dead cells. Well, I'm a bit confused - why do they do this? Aren't there any cells nearby which are the ...
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RNA Molecule folding

For a Single Stranded RNA Molecule : A) Adenine Content Always Equals to Thymine Content B) Cytosine content Equals to Guanine content C) Adenine content Always Equal to Uracil D) Guanine content ...
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How many cells should be seeded for passaging?

Do you count cells when you passage them? I found that many people will according to a ratio (maybe 1:2 or 1:3,etc.) to subpackage. It is so indistinct! What is the optimal seedling density or ...
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What exactly is a reducing equivalent and what does it do? [migrated]

I've encountered this term in the context of cellular metabolism, but I can't seem to find an explanation of what a reducing equivalent is or why it is named this way. Wikipedia was not really helpful,...
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Is callus totipotent or pluripotent?

Is callus (in the context of plant tissue culture) totipotent or pluripotent? As I understand, the difference between totipotency and pluripotency is an ability to differentiate into extraembryonic ...
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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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Why are sex abnormalities more likely to survive than autosomal abnormalities?

I found that it is because of dosage compensation mechanism to counteract genetic imbalance between males and females , but i didn't understand it , please can you explain it
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Why biologic systems tends to become more complex?

From elements, chemical compounds, cells, multicellular organisms, society evolves and with each step possibilities increase and things get complex. We are builing structures like ribosome builds ...
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Do epigenetics determine the proteins a cell produces and therefore it's function?

I'm having trouble understanding what epigenetics is in a simple sense. How I imagine it is that if we had 2 twins with identical DNA and we let them live we will see that they'll develop differently....
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Osmotic Pressure Clarification

My textbook states that the higher concentration of solutes, the greater the osmotic pressure will be and the greater the pull of water in will be. However, osmotic pressure is defined "as the ...
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1answer
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James Allison's T-cell discovery technique

The excerpt on Wired magazine of The Breakthrough by Charles Graeber has the following description of how James Allison found the T-cell receptor. Suddenly it seemed so obvious: If Allision could ...
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1answer
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When muscles contract is the process similar to how non-newtonian fluids react?

I'm trying to understand how muscles contraction/tension works but getting loss in on the cellular level. From my understanding, when muscle tissue need to contract, the cells are flooded with calcium?...
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How to take precise/low number of cells from cell lysate? [closed]

I would like to know that how can we take low or precise number of cells from a cell lysate? (without using any protein quantification assay). Let say, If I have a cell line having cell density 5x10^...
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Glycolysis of respiration

What process provides directly ATP for the cell? It is glycolysis because it generates 2 ATP in cytoplasm. How many times ΑΤP are available from glycolysis when compared to ΑΤP of cellular ...
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RDW values in teenagers

What is the normal range for RDW( Red blood cell Distribution Width) in athletes. Is 16-17% values high or normal for national team athletes(ages around 12-14years)?
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can magnesium bicarbonate be absorbed in the mouth?

Can Magnesium Bicarbonate be absorbed in the mouth?" Magnesium Bicarbonate occurs naturally in some mineral waters.
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What is the meaning of the following: “ completion of open rounds of DNA replication”?

I am studying a paper about the relation between polyP granule and cell cycle exit. As the author explained the four general steps for cell cycle exit, the second step is" the completion of open ...
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1answer
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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
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Univocal identifying of a plant cell

We yesterday got our biology-exams back and there's one exercise where I don't agree with my teacher. However, since he is the expert and not me, I need the support of external sources, i.e. experts ...
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Why don't the heads of phospholipid bilayers repel hydrophobic molecules?

What I Think I Know: Hydrophilic and hydrophobic things repel each other. Since the cell membrane contains hydrophobic tails, it is difficult for hydrophilic molecules to pass through the cell ...
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1answer
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Do all animal cells have lysosomes?

I know that white blood cells have lysosomes but what about other body cells? I mean, any other cell such as cells in the respiratory system.
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Are cell biology and cytology the same science?

According to Wikipedia, the terms can be used interchangeably, but according to my college professors, cytology is exclusively the study of chromosomes and identification of their abnormalities.
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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 ...
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Where is ethanol detoxified? peroxisomes or smooth ER? Or both?

I am reading the textbook Biology (Campbell et al, 2005), and I am confused. In Chapter 6.4, on page 104, it says that "In the smooth ER, other enzymes help detoxify drugs <...>", and alcohol is ...
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1answer
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Centrifuge after sonication

I follow a protocol to get protein from E.coli cells after sonication. I used to grow 6 litres of large cultures and add IPTG to express the protein. I centrifuge for 10 mins at 8,000 rpm and get the ...
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1answer
60 views

Protein electrophoresis

Three proteins A, B and C of equal molecular weight are being investigated in a study. They contain six, four and four cysteine residues respectively. Only Proteins A and B were treated with β-...
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Why does pyruvate from lactate and pyruvate from other sources follow different pathways in gluconeogenesis?

My teacher taught me in a lecture that PEP forms from Pyruvate by two ways, based on their sources, that is - 1. If the Pyruvate was from lactate (by lactate dehydrogenase action), it gets shuttled ...
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0answers
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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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1answer
38 views

Gluconeogenesis in the liver

Glycolysis yields 2 net ATPs. However, gluconeogenesis (lactate->pyruvate->glucose) costs 6 ATP, with a total net loss of 4 ATP. Does the body not care about the net loss because of the potential ...
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2answers
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When two amoeba cells form from one amoeba, does spindle fibers form?

When two amoeba cells form from one amoeba, does spindle fibers form? Some sources say that spindle fibers do not form while an amoeba cell is undergoing cell division. If spindle formation does not ...
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1answer
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Why do we have an immune system?

My daughter asked a question that I could not answer. If you have a cold, you have symptoms such as fever, cold and sore throat. These symptoms, however, are the reactions of the immune system to ...
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What are the fibers and small droplets on the surface of dividing HeLa cells in the figure?

I did some literature searching but could not find any info probably because I did not know how people name them. The figure is from the wikipedia entry HeLa
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What are the effects of enzyme exposure to high temperatures? [duplicate]

Question: After enzymes are exposed to high temperatures and undergo denaturation, then returned to their optimal temperature and renatured, can the enzyme's active site return to it's original shape ...
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1answer
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Are androgenic-anabolic steroids a form of gene editing?

Is taking AAS a form of gene-editing? Steroids alter genes in some way since they allow people to build more muscle than what's naturally possible -- so they sort of "break" natural genetics somehow. ...
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1answer
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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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Rod and cone photoreceptors are neurons?

i mean the photoreceptors have axon and dendrite and body cell or it is not neuron any more . can we say outer segment of photoreceptor cell is dendrite ? of course these have body cells but i am ...
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Comprehensive database of cell types

Wondering if there is a comprehensive list/database of cell types, similar to this wiki list of cell types in the human body. It lists probably 100+ different types, but this is just for a human. If ...
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Is there any evidence of homologous somatic pairing in taxa aside from Dipterans and budding yeasts?

Homologous somatic pairing is the physical colocation and pairing of the paternal and maternal chromosomes in a cell during growth phases of a cell. This is interesting as most taxa that we know about ...
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Why do soap molecules not break down your skin cells when you wash your hands?

Soap molecules are similar in structure to phospholipids and interact with the cell membrane. They can clearly cause damage to the cell membrane. If this is the case, why then, does soap not break ...
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1answer
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Skin (histology)

Our instructor share this image with us. She didn't specify much. She only said it was a skin sample. Could you tell me what is the thing that was pointed at with the blue arrow? I believe that I ...
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3answers
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You need DNA to make RNA, and RNA to make DNA, so they had to come into existence at the same time?

A statement I recently read: 'Evolution is debunked and gives no basis for morality. Natural Selection throws away info, it does not add. You need DNA to make RNA, and RNA to make DNA, so they had to ...
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Why does a lightsource postpone the time it takes for the leaves falling from a birch?

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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2answers
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Tissue fluid water potential

just a quick question. Is the tissue fluid the same water potential as the cells it surrounds? I am a bit confused because if it was lower it would cause water to leave the cell and if it was higher ...
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2answers
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How are cell death like apoptosis and entropy related?

In Perspectives on Statistical Thermodynamics, Yoshitsugu Oono, it is written that Do not conclude, however, that since the second law is invincible, information thermodynamics is unimportant. It ...
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Do plants experience the following feelings

I am not a student of biology,in other words I have not read biology much. But I read that plants have life and so my question is the following: Suppose I take two saplings of two different ...