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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Rate of cell division in humans

On average, how many cells divide each day in a human being? How long does a cell wait before dividing itself ? I have tried to look on the internet but surprisingly the answer is difficult to ...
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3answers
866 views

Do we consume dna, proteins of other organisms?

When we eat raw meat, e.g. chicken or fish, we are actually consuming the DNA, proteins etc. which are present in their cells. Wouldn't this affect our cell functions as this DNA might enter our ...
3
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1answer
179 views

Membrane Permeability to Pyruvate

Pyruvate seems to pass easily through the outer membrane of the mitochondrion but has difficulty entering the inner membrane (and gets in by H+ symport). I have two questions: (1) what property of ...
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0answers
52 views

What are the sizes of the cells that make up human hair?

The question is in the title, but I'll explain why the question arose. I'm curious about the rates that various cells in the body divide, and have found various information relating to this, but ...
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0answers
39 views

How to use DRAQ5 and MitoTracker CMXros dyes to stain turtle erythrocytes?

I am working on turtle species and want to use DRAQ5 and MitoTracker CMXRos to stain turtle nucleated erythrocytes. Can anyone suggest me a protocol to carry this stain out? Would the two stains ...
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1answer
71 views

Introductory book to cell biology

I am studying the human circulatory and respiratory systems to develop tools for automated diagnosis of disease. During the past year, I have read basic books about respiratory physiology, ...
2
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1answer
76 views

Why do cells not spread on soft substrates?

I recently read a paper discussing how cells (primary mouse embryo fibroblasts) fail to spread and proliferate properly when plated on a soft substrate (i.e. soft PDMS pillars with stiffness k = 2.3 ...
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3answers
35k views

Do animal cells have vacuoles?

I overheard a rather heated argument about whether or not animal cells have vacuoles. One person said that they do, but they're much smaller than vacuoles in plant cells. The other person said they ...
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0answers
77 views

What is the essence of difference of how different chemicals affect the same receptor?

It is known that various chemicals can bind to the same receptor type, producing different effects. Be these chemicals agonists or antagonists, there are more variations in how they influence the ...
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749 views

How is centriole number maintained during meiosis?

I've found a website (Pearson's BioCoach) that claims centrioles duplicate in Prophase II. Is this accurate? Does it depend on the species in question? Looking at three textbook illustrations of ...
2
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1answer
256 views

How to understand certain protein names

I am looking for a reference to help me understand what is meant by acronyms such as : H3K9me1, H3K9me2, and H3K9Ac. I know that these are all histone proteins, but is there a general nomenclature ...
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46 views

Self assembly of Golgi Apparatus

Self assembly is not a new phenomenon to biology. Many things self assembled to provide full fledged functional unit. There are two conflicting theories about formation of Golgi Apparatus, Template ...
22
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3answers
371 views

How crowded is the bacterial cell?

I was wondering what is the protein concentration in an E. coli cell. When studying enzyme kinetics and activity in vitro, I would argue that the substrate and enzyme concentrations resemble those in ...
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125 views

Catenation and decatenation by DNA Gyrase

Decatenation is done for the replication of DNA and why is Catenation done and is it related to Crossing over
2
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1answer
149 views

What is a mechanical cue?

I was attending a talk related to neurogenesis. So one professor was asking a question related to biochemical cues and mechanical cues (related to signaling pathways I believe). Cue as far as I ...
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1answer
148 views

How will changing the concentration of a Tris buffer affect amylase enzyme activity?

For instance if you increase the amount of Tris but pH still does not change then will the enzyme activity still proceed normally? If it does change the pH will it change enzyme structure and why?
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2answers
45 views

Question about flux and changes in net flux of molecules across a membrane

I've been reading a book called Principles of Human Physiology by Stanfield 5th edition, and was reading a chapter on membrane transport when I came across a figure question which will be posted ...
5
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1answer
88 views

How do single-celled predators chase other cells?

From my understanding, single celled organisms have been seen avoiding, and chasing, potential food or other organisms. How do they accomplish this? They do not have eyes or ears or a nervous system. ...
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1answer
60 views

Why are siblings unidentical? (Which chromosome of the pair do gametes have?) [closed]

I know that a normal human cell has 23 pairs of chromosomes (total: 46). On the other hand, a gamete has only 23 chromosomes. Which chromosome does the gamete choose out of each pair? And if "One of ...
7
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1answer
482 views

What causes Paresthesia (Pins and Needles) at a cellular level?

I've looked it up in plenty of places like the Wikipedia page and such, and it is clear that the most common cause of Paresthesia is either a fair amount of pressure on a specific patch of skin ...
6
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1answer
88 views

What is the fate of micronucleus DNA?

Micronuclei are cellular structures that are formed as a by-product of, usually, defective mitosis. The piece of chromosome in a micronucleus may, or may not contain a centromere and the DNA is ...
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6answers
3k views

Why would a single celled organism evolve to be multi-celled?

I read a story this week on Richard Lenski who has been 'evolving' E. coli for more than 50,000 generations now. One comment I read was from someone who doesn't accept Evolution who pointed out that ...
3
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1answer
3k views

Is the ringing sound in the ears caused by dying ear cells?

I was recently watching the movie "Children of Men" (great movie) by Alfonso Cuarón. Now in a certain scene, the lead actor happens to be nearby a loud explosion. Later, when he complains about the ...
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0answers
36 views

Can ' functional' stress 'forced upon' a cell actually cause cell mutations when they divide and reproduce?

If a group of cells are forced to go beyond their regular biological parameters that they should be under given ' healthy' functioning and while existing in these stressed states some of the cells ...
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1answer
362 views

What is the biochemical reason for mental fatigue?

Is it known exactly why the brain needs sleep? What's dropping low / going high when we experience mental fatigue? I can see why low glucose could result in mental fatigue, are other reasons known?
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2answers
550 views

Should we induce fever to assist healing?

I am currently reading "The Fundamentals of Anatomy Physiology" 10th edition, and have found it an incredibly interesting book. I have just been reading about the lymphatic system, and the various ...
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0answers
26 views

Can mutation rate be increased for instance by mutagenesis targeting the DNA polymerase?

I am studying a non-cultivable bacterium living in an insect host, and I would like to generate some random mutants of this bacteria while preserving the insect. I am wondering if one way to do so ...
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1answer
149 views

Staining cells for FACS at 4 degrees or ambient temperature

I'm sorting a 293 derived line. One thing that is worrisome for me is cell viability after the sort. Usually I have been staining and washing at room temperature (on the benchtop) on a nutator. I have ...
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1answer
247 views

Do RBCs need oxygen?

How do our red blood cells (RBCs) get oxygen? Do they even need it? They have no nucleus and no organelles, so I think they don't need it.
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1answer
87 views

How does the structure of the pancreatic acinar cell relates to its function?

So the pancreatic acinar cell synthesizes, stores and secretes digestive enzyme precursors called zymogens e.g. pepsinogen. The structure of the acinar cell shows that there is an apical and basal ...
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2answers
139 views

Does polyploidy always isolate the polyploids from the diploid source population?

I am receiving conflicting information while researching polyploid speciation. On the one hand, some sources state that a polyploid can only reproduce sexually with polyploids having the same number ...
3
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1answer
82 views

What happens to the excess immune cells or WBC in our body?

When we have an infection our immune system produces a large amount of white blood cells (WBCs) in our body to fight against the pathogen or parasite. My question is after the immune response has ...
10
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1answer
491 views

Does the cell internal temperature changes in response to a change in external temperature?

Background Some species are homeotherm (internal temperature is not affected by a change in external temperature) and some are poikilotherm (internal temperature changes in response to external ...
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1answer
413 views

When does DIFFUSION occur and not OSMOSIS, and the otherwise?

For example, I do know that red blood cells have both the Na+/Cl- co-transporter and Aquaporin (water channel) that allows both Na/Cl and water molecules to pass through. But why in biology textbooks ...
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119 views

Jurkat single cell clonal expansion

I'm hoping to do a clonal expansion of Jurkat, expressing my construct which is currently transduced virally. From the FACS data I currently have roughly 30-40% expression in my culture but I need it ...
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1answer
164 views

How long do human egg cell grow up?

I read article about alcohol harm where written that child may bear with birth defect cause mother used to drink alcohol 10 years ago so egg cell stay damages that long. I don't believe that human ...
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0answers
76 views

How to mimic / approach some animals/insects' anabolism?

This article states that some shelled animals - spiders, scorpions, crabs, worms and other creatures - have metal atoms in their claws, jaws and fangs. I believe through anabolism, since they eat ...
3
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0answers
94 views

L-tryptophan in mammalian cell culture

Why must the concentration of L-tryptophan be kept to a relatively low level when culturing mammalian cells? It's an essential amino acid, so I cannot fathom why low concentrations as opposed to ...
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28 views

Is a Ribonuclease Inhibitor protein the only mechanism employed by the human cell to protect cellular RNA from degradation by endoribonuclease?

Are there any other methods of protection for cellular RNA from degradation by endonuclease (specifically the Pancreatic Ribonuclease RNase II (Eosinophil-derived neurotoxin) and RNase III (Eosinophil ...
3
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1answer
187 views

What is a functional screen?

I was going through this paper, but did not understand a term. What is the meaning of functional screen? (I am not a biology student, I don't understand much, and a small simple explanation would ...
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0answers
26 views

Are there any auto-immune diseases caused by T cells not detaching from antigen presenting cells (APCs)?

By not detaching I'm referring to after they have formed an immunological synapse, if they don't ever detach.
28
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2answers
6k views

Why do tattoos persist if body cells are regularly renewed?

I am not quite sure if it is true, but I read somewhere that within 7 years all the body's cells are replaced with new ones. I am not quite sure if it is cells or atoms. If it is then why do tattoos ...
9
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2answers
4k views

What are the differences between cancer and tumour?

What are the differences between cancer and tumour? I mean is it in the DNA or shape or something else... And how can a benign tumour turn into a malignant tumour? The body has a lot of tumours all ...
6
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2answers
563 views

Are there any multicellular forms of life which exist without consuming other forms of life in some manner?

The title is the question. If additional specificity is needed I will add clarification here. Are there any multicellular forms of life which exist without requiring the consumption (destruction) of ...
8
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2answers
218 views

Are mitochondria transferable between cell types, individuals and species?

I'm curious about what happens when you insert organelles from a cell into another. In particular, mitochondria. Take two cells from your own body. Somehow extract a mitochondria from one cell and ...
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2answers
592 views

Does ATP hydrolysis reaction have a high or low activation energy?

I was recently studying about ATP and how it functions as an energy carrier to all biological processes; however, I came across a confusing and paradoxical statement from two sources: (at 7:36) and ...
2
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1answer
58 views

How semi-synthetic cell with artificial DNA works

I know that by now this is old new but I heard that a cell that used a synthetic pair of nucleotides, called X and Y, have been made. My question was, how did the cell understand the X and Y ...
6
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1answer
54 views

Spatial learning in microorganisms

Has there ever been an experiment performed that demonstrated a form of 'spatial memory' in a unicellular organism? I'm imagining something analogous to the classic 'rat in maze' experiments, but ...
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3answers
1k views

Methods of nuclear transfection - nuclear transport

I am reading through the ENCODE papers, which is taking me well out of my comfort zone in terms of modern laboratory techniques. At the risk of asking a question which may well be thoroughly answered ...
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3answers
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What is the distinction between chemokines, cytokines, interferons and interleukins?

They all seem to describe molecules of similar function and many people seem to use them interchangeably. Also please include any other similar molecules if I've forgotten any in the list above.