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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house keeping gene variation under treatment

I am injecting BCG in mice ears to measure the local inflamation response in the infection side, one ear in the same mouse is kept as control by injecting PBS, in the other one, BCG is injected. When ...
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105 views

Missing 4 $\ce{H_2O}$ (per glucose) in Cellular Respiration… Where can they be?

I having trouble understanding the equation of the cellular respiration. The thing that bothers me is the number of $\ce{H_2O}$ molecules. Generally, cellular respiration is written thus : $\ce{C_6H_{...
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18 views

Function of the centriole

My bio text book says Centriole is like the Nucleus of Centrosome What does this mean ? I'm a bit confused.
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26 views

Mitochodria's Role For Neuron Regrowth

Recently an interesting study has reported. Zhou et al., 2016. J. Cell Biol. http://dx.doi.org/10...3/jcb.201605101 According to this study, enhancing anterograde axon transport of mitochondria is ...
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5 views

Genetic diversity of Archae attributable to viral transduction?

I recognize that bacteriophages have the ability to accidentally trap host Bacteria DNA upon assembly. This allows the transduction of one bacterium's DNA into other bacteria when the virus ...
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52 views

The mechanism of cancer metastasis

Generally, EMT, Epithelial to Mesenchymal Transition is thought to be involved in the mechanism in which cancer cells metastasize in the early stage. EMT is an process in which epithelial cells ...
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1answer
38 views

Plant cell question in age 12 science test Part II

I'm a parent and I think the teacher had been a bit harsh with marking most of these questions but can someone help me answer the very last question on the paper please (where someone has written SP ...
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1answer
33 views

Plant cell question in age 12 science test

Can anyone help me answer the questions in the attachment about plant cells. It was a question in my 12 year olds science exam. I'm baffled as I think he has given a good knowledgable answer but it ...
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1answer
44 views

Enzyme Inhibition in relation to Aspirin

I've been trying to learn a bit more about pharmacology, so bear with my ignorance. In short, I see that aspirin (in part) works by inhibiting cycloxygenase isoenzymes and that this inhibiting is ...
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26 views

Can You explain this readtion? [closed]

Reagents bind to the functional group of biological molecules by covalent or non-covalent bonding or interactions. Explain this interaction between each reagent and its prospective functional group.
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2answers
80 views

Does the formation of water inside the mitochondrial matrix help contribute to the proton gradient during the electron transport chain?

Does the synthesis of water in the final step of the electron transport chain significantly increase the electrochemical gradient across the matrix? I understand that pumping protons out of the matrix ...
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1answer
38 views

How do RBCs survive without a nucleus?

So, I was reading this question Why do mammalian red blood cells lack a nucleus? Now, I do not yet have the privilege to post a comment and so I am forced to create a new question to clear my doubt. ...
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1answer
21 views

Can cell division be stopped during prophase?

There are three known checkpoints which ensure proper division of the cell. These are: the G1 checkpoint, also known as the restriction or start checkpoint or (Major Checkpoint); the G2/M ...
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1answer
61 views

Maintenance of Diploid chromosome number at mitosis

I'm just not understanding this: A regular human cell is diploid - because it has 46 chromosomes, in 23 pairs. So that means that when the cell undergoes mitosis, it will still have the full ...
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1answer
15 views

How do centrioles auto-locate to opposite sides of cell during mitosis?

I realize that centrioles are made of 9 triplets of microtubulin wound together with a hollow core, and that they are responsible for the configuration of the spindle during mitosis. The spindle ...
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2answers
4k views

Are there human cells, apart from red blood cells and platelets, without a nucleus?

I know that blood platelets and erythrocytes do not have a nucleus. Are there more cells in the human body without a nucleus, such as pancreas, cartilage, or lung cells?
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48 views

If the liver can regenerate why can alcohol abuse permanently damage it?

The liver is a fairly unique organ in that it has the ability to regenerate itself even if parts of it are removed/damaged. It is a well known fact that continual alcohol abuse damages the liver and ...
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3answers
210 views

Do chromosomes uncoil in interphase II?

During interphase II, there is no S phase in which DNA replicates. However, in this stage, do the chromosomes remain wound? Or have they unwound into chromatin form, and recondense during prophase II?
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2answers
27 views

Good microscope? [duplicate]

Hi I am a teenager and I recently studied biology and found it very interesting. I want to get a microscope and study further into the microscopic world. What would be the best microscope for me? I ...
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1answer
47 views

Is there a certain environment where all cellular functions (or at least some) increase their rate?

Is there a certain environment in which all the functions (or some) inside a cell increase in their rate? Would the increased rate cause any damage to the cell?
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1answer
22 views

What does “cell type composition” mean?

I am reading an article about detection of differential methylation. They use the term "cell type composition" in the following context: "Researchers need to carefully design studies that associate ...
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1answer
39 views

Does having to urinate imply that you are becoming dehydrated?

This question came up after I read another question that coffee does not dehydrate you, but instead acts as a mild diuretic. Does having to pee imply dehydration? Allow me to elaborate: When you ...
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0answers
32 views

Problems with housekeeping genes

I have tried several housekeeping genes to analise the relative expresion of a cytokine for measure the inflamatory local response in mice ears, all the housekeeping genes I have tried are not stable (...
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2answers
66 views

Why must DNA be packed into chromosomes during mitotic phase?

Why does DNA have to be packed into chromosomes? Why can't DNA just divide itself evenly?
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2answers
171 views

Blebbistatin effect on vesicles

Blebbistatin is a drug that specifically inhibits the assembly of myosin in the cytoskeleton. What effect would you expect blebbistatin to have on intracellular vesicles? ...
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2answers
60 views

Where do transamination and deamination take place?

The only information I know is about deamination is that it occurs in the liver and kidney. But in which part of the cell does deamination occur? To which tissues is transamination specific, and in ...
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1answer
68 views

When did death due to aging first appear? [duplicate]

As I understand it, single-celled organisms that reproduce via mitosis essentially live forever. When a cell divides, one cannot say that either one of the new cells "is" the parent and the other the ...
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28 views

Questions about Genetic algorithm paper of Gilman and Ross

I want to reproduce an (old) biochemistry paper of Gilman and Ross, i.e. " Genetic algorithm selecetion of a regulatory structure that directs flux in a simple metabolic model." ( The following link ...
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1answer
123 views

Which are the last cells of the human body to die?

When somebody dies, which are the last surviving cells of his/her body? Those of hair, nails, or some other obscure but resilient cells? Shedding light on why and how they are so vital might boost ...
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2answers
55 views

Diffusion coefficient of cells in blood?

What's the diffusion coefficient of white cells in blood? Is it well defined, or are cells too large and few as to be treated as particles in this context? P.S. I have tried to look this up, but what ...
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2answers
4k views

Are mature erythrocytes prokaryotic?

Mature mammalian erythrocytes have all the characteristics of a eukaryotic cell except that they don't have a nucleus, they don't have any cell organelles. Does this mean that erythrocytes are ...
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22 views

How does plant life obey the constraint that the change in Gibbs free energy in a reaction must be negative?

My understanding is that if a reaction takes place, either entropy of the system must rise, or energy must be released from the system as heat, or both. (Citation: paraphrasing from The Vital Question,...
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7 views

Obout oxygen presence in krebs cycle [duplicate]

Q- If oxygen is not utilized in the cycle then why it is present in the Krebs Cycle?
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0answers
16 views

What are extracellular matrix pathways?

I was reading a research paper dealing with acute myeloid leukemia and the term "extracellular matrix pathway" came up. What does it mean? I found literature on extracellular matrix, but I'm not sure ...
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3answers
75 views

Doubt in a multiple choice question involving cell organelles

Find the odd one out and state the category of the rest. Chloroplast Mitochondria Nucleus Grana Now my answers are : 1st possibility : grana Category : presence of DNA in ...
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0answers
20 views

Do Tumor-Infiltrating T Cells Experience Any Prolonged Effects Due To Hypoxia After They Return To Normoxia?

Adoptive cell transfer (ACT) therapy using tumor-inflitrating lymphocytes (TIL) is at the cutting edge of immuno-oncology treatments involving metastatic melanoma and other indications (1). The idea ...
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2answers
87 views

Why does azithromycin not affect human mitochondria?

Drugs like tetracyclines, macrolides and aminoglycosides bind to prokaryotic ribosomes. It is interesting that our body too having mitochondria, which have prokaryotic ribosomes, there is little(?) ...
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0answers
479 views

Why do some white blood cells have lobed nuclei?

Several types of white blood cells (eg Neutrophils) have lobed nuclei. Is this for a functional reason? I have seen people refer to structural differences in the lobes as indicative of problems, but ...
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1answer
37 views

What is the difference of function between palisade and spongy layers of leaf? [closed]

I was just wondering what is the difference between palisade and spongy layers of leaf?
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4answers
7k views

Why do cell membranes have a lipid bilayer instead of a monolayer?

Many cells have a cell membrane composed of two layers of lipids. Why is it that they have two layers and not just one? What purpose do this arrangement serve?
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34 views

How does DNA organise a cell's physical position within a body?

How do cells "know" where they are supposed to be in relation to other cells, in forming the physical shape of the body? If you have ever tried to organise or choreograph the physical positions of a ...
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1answer
378 views

Why should phospholipid non-polar tails be “protected” in the membrane bilayer?

lipids are arranged within the membrane with polar head towards the outer side and non polar tails towards inner side, this ensures that the non polar tail is protected from aqueous environment. My ...
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1answer
319 views

Is reproduction intrinsically part of life? [closed]

If all of the characteristics of life are required for something to be defined as living, how can we account people or other life that can not reproduce?
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11 views

Does alcohol affect water potential across a tonoplast? If so, would it cause it to explode or implode?

This was a question I saw in a biology exam I recently sat. I know it affects the r-groups of the transport proteins, causing them to change shape and become leaky, but does it also affect water ...
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1answer
89 views

What is the mass of an E.coli cell?

I'm trying to get into Biology, reading introductory texts. A discussion on E.Coli estimates the mass of the cell from $$density =1g/mL=1g/cm^3$$ and $$volume=1µm^3$$ From this I get $$ mass=density × ...
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1answer
30 views

Does common X-like picture represent one doubled chromosome or two homologous chromosomes?

What is on common X-like picture of chromosome? Here is the image from Wikipedia: Are (for example) lower petals homologous to each other? If yes, then why (1) ...
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2answers
35 views

How does the peptidoglycan layer of a bacterial cell wall help prevent osmotic lysis? [duplicate]

I recently read that penicillin works by damaging the peptidoglycan layers of a bacterial cell wall causing osmotic lysis, which is when the bacteria cell bursts due to osmotic pressure. I just ...
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1answer
58 views

How do cells age and die if they are dividing into new cells?

If cells in our body keep on dividing into new cells how do they ever grow old? The only cells to grow old would be defunct cells or those who won't divide into new cells like nerve cells. What am I ...
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1answer
22 views

Using exogenous genes to reduce the set of essential amino acids?

Various organisms have sets of essential amino acids that they cannot synthesize themselves, but rather that they must obtain from food. Humans have 9 of these amino acids. However, obviously certain ...
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1answer
30 views

How do normal cell division chance into a tumor forming cell division? [closed]

Or its better to say what happens at molecular level that tumors are formed? I tried normal google search and google books but couldn't find any appropriate explanation. I am trying to understand why ...