Questions tagged [cell-division]
Cell devision is the process in which one parent cell divides into two daughter cells. The interiour (cytoplasm, DNA, mitchondria etc.) of the parent cell is divided between the two new cells.
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Why is There a Necessity for Two Rounds of Cell Division and Four Daughter Cells in Meiosis
Why does meiosis involve two rounds of cell division instead of stopping after meiosis I, where each daughter cell would have one chromosome randomly selected from each pair of homologous chromosomes? ...
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Does the smoke produced by tobacco affect mitosis in vegetables (plant cells)?
There is a plethora of literature and research studies on the effects of tobacco on the human body and other animals.
I am interested in knowing whether the rate of mitosis in plants is affected by ...
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When shall we call a secondary Oocyte an Ovum?
My common sense tells me that once ovulation has occurred and the secondary Oocyte is out of the Ovary ,it should be called an Ovum, but my son's high school biology text book mentions a secondary ...
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If crossing over did not occur, would pairs of cells after meiosis II have the same genes?
If crossing over did not occur, would there be two pairs of cells with the same chromosomes after meiosis II? This question came to my mind while I was reading through my bio textbook. After meiosis I,...
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How does the cell-wall ultrastructure of gram negative bacteria justify it being unable to Sporulate?
The following is a quote from my Microbiology Lecture PPT: "Some gram positive bacteria but NEVER gram negative ones produce spores under harsh conditions".
It got me wondering why gram ...
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When do retinal cells stop differentiating? [closed]
I am having a hard time recalling where I had heard this, but I do recall someone saying (perhaps in a video) that cells in the retina divide very rapidly during infancy due to ongoing development of ...
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What does this statement pertaining to fission mean?
I was reading about fission on Wikipedia when I encountered the following statement under Fission of prokaryotes section.
Like in mitosis (and unlike in meiosis), the parental identity is lost.
What ...
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What is the average rate of red blood cell production in humans?
I was doing my biology research of the day and I came across the following question: How fast are red blood cells produced and, how do I calculate this?
I am currently using the following:
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What is bacterial (prokaryotic) cell division called?
Eukaryotic asexual cell division is sometimes referred to as mitosis, although this is more strictly used to refer to the specific stage at which “the replicated chromosomes separate into two new ...
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Why does Meiosis produce 4 daughter cells instead of 2? Won't splitting the initial diploid cell into two haploid cells be easier?
At first, I thought it was because of crossing-over, but when I thought more about it, that didn't seem reasonable. Why don't cells just do meiosis like this? (I know that we don't understand all the ...
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Could someone explain how chromosomes are counted here?
I'm not sure how chromosomes are counted in this picture. I would reason that there would be 8 chromosomes in the diploid cell, but that doesn't seem to be the case. Could someone explain?
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How is RNA content distributed in daughter cells during cell division?
During cell division, DNA becomes equally distributed between the daughter cells. But how is RNA content distributed in the daughter cells?
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homologous recombination and non-homologous recombination ratio during S-phase
Can I assume that it is easier to do targeted gene knock-in in rapidly dividing cells because they should have a short period of G1? Is there an easy way to measure the relative amounts of homologous ...
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How do viruses provide selective advantage
I've heard in many talks as a passing, well-known fact that viruses(e.g. pathogenic HPV strains) offer selective advantage for the infected cell to multiply. But I'm not able to quite wrap my head ...
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Cancer in cardiac cells
We were recently taught that cancer occurs only in those cells which undergo cell division so, cancer is not possible in cardiac cells and neurons.
But we know that till a certain age our heart grows ...
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Why is a cell in anaphase (without a nuclear envelope) be considered as a eukaryotic cell?
Can anyone shed some light on this? All I can think of is that it has something to do with the chromosomes being paired
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From stem cells to fully differentiated cells
I'd like to understand better how stem cells produce fully differentiated cells via progenitor cells. I assume the following:
Only cells that are not fully differentiated do divide at all.
When a ...
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How and when does the regeneration of cells that have died start?
I assume that the replacement of cells that have died (or been removed by any means) doesn't work on a single cell level but starts only when some critical number of cells have died.
My question is: ...
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How are cells that have died replaced by new ones?
I'd like to have a clearer picture how cells that have died are replaced by new ones.
I assume the following:
Normally, when a cell dies it will be replaced by a new one of the same type.
It will be ...
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How many times have the cells in a human body divided?
Every single cell in a multicellular organism can in principle trace its "ancestry" back to the zygote through a continuous chain of cell divisions. How many divisions have occurred in a typical cell ...
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Why do chromosomes uncoil back to chromatin after cell divisions?
At the telophase of meiotic and mitotic cell divisions, the chromosomes of daughter cells uncoil back to chromatin, but after interphase, it coils up again to form visible chromosomes. Why do this ...
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Name/term for mechanisms by wich the relative size/number of cells of some tissue/organ are preserved
The cells of some organ or tissue are dividing and also dies (apoptosis). But this happens in somehow controlled manner so that the total size of the organ is approximately preserved or the total ...
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Why don’t plant cells need centrioles? [duplicate]
I’ve just learned about cell division and I noted that plant cells don’t have centrioles but still undergo cell division. I’ve read a few documents about it and wondered why plant cells don't have ...
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DNA replication - 2 new strands or original (parent) and child?
this is my first time here, so go easy on me! I've been trying to find out more about the actual process of DNA replication. Specifically, I am wondering if, when the DNA replicates during cellular ...
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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.
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In cell division, are daughter cells "newer" than the parent cell?
I learned that cells go through cell division to generate new cells to replace dead or damaged cells.
Are the daughter cells "newer" than the parent cells? For example, the parent cell has an "age" ...
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Beyond anabolism, what are factors that restrict growth rate?
Beyond obvious constraints in the case of nutrient limitation, what can explain the relatively slow growth rate of cells in rich media?
Lab strains of E. coli grow really, really fast. The cell ...
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How do adult differentiated somatic cells divide?
My textbook (which is Biotechnology by David P. Clark) states, when talking about fate-mapping potential stem-cells:
"If the marked cell is not a stem cell, the marker will not be passed
onto ...
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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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Which is the correct term haploid daughter cells or haploid parent cells?
Meiosis 2 begins with 2 haploid parent cells and ends with 4 haploid daughter cells (gametes). Gametes from the opposite sex can now merge together and fertilize.
If I were to refer to a specific ...
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How long does each of the stages in meiosis take?
For each stages of meiosis (i.e. Interphase, Prophase I, ...), I wanted to know the time between each stages either in percentages or minutes. However, while I could find the cell cycle for mitosis ...
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Can a viable embryo develop from the fusion of two egg cells?
For a zygote to form, two haploid gametes undergo meiosis and fuse during fertilisation. Since two egg cells (or even two sperm cells) are both haploid, is it theoretically possible for them to make ...
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How did genome replication first synchronise with cell division?
It is obvious that cell division in living organisms is now synchronised almost perfectly with DNA replication and, furthermore, the line of division has to intersect exactly the space between the two ...
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Why are humans only so tall/large?
In biology I've learned that cells rapidly divide and can grow and split undefintely, and that certain parts of the body have to grow and evolve before growing, but I am tied up on the fact that the ...
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What organism has the longest Hayflick Limit?
Assuming I am understanding the concept correctly, Hayflick Limits are reflective of a cells capacity for stable division. Additionally, the Hayflick Limits of various organisms differs.
My question ...
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Why are stem cell therapies more preferred (theoretically) over current measures?
i understand that when stem cells are used to treat injuries using induced pluripotent stem cells (IPS), they can prevent the risk of having any tissue rejection and thus, there isn't a need for use ...
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Stem Cell Replication
Reading from the internet, I've come across quotes that said stem cells have the potential to replicate indefinitely. However, there are other sources that say cells that are specialised will have ...
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Why does cell waste energy in meiosis, between meiosis 1&2
As far as I have learnt about meiosis I have read that anaphase 1 is followed by telophase 2 where chromosomes change back to reticulum.but in the very next stage i.e prophase 2 they again start ...
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Mitosis in free nuclear divisions
When free nuclear divisions occur(for instance in endosperm formation in coconut etc)....there are many nuclei undergoing kartokinesis at a given point of time...so that means each karyokinesis will ...
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Names of different cyclins
Different types of cell cyclins are designated as a to y
Why are some letters like m, n, p, q.. etc. skipped?
Source: https://en.wikipedia.org/wiki/Cyclin
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When does the kinetochore form?
According to Wikipedia,
the outer plate... is assembled in the surface of the chromosomes when the nuclear envelope breaks down.
However is makes not mention of when the inner portion of the ...
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Genetic information storage and the extent to which it controls appearance/structure
So there are often articles about cloning from a small piece of tissue etc.
My question is (two actually) Is the Complete information about entire organism's structure stored (as in duplicated) all ...
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How are germ cells not reduced in number?
If germ cells produce haploid daughter cells by meiosis and are thereby "consumed" (where there was a germ cell there are then 4 daughter cells), where do the germ cells come from? I asked my biology ...
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Why doesn't cellular, replicative senescence (or the hayflick limit) constrain the normal development of an organism?
The wikipedia article on cellular senescence states:
Cellular senescence is the phenomenon by which normal diploid cells cease to divide. In culture, fibroblasts can reach a maximum of 50 cell ...
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How do cells determine what size to grow to before dividing? [closed]
How do cells determine size to grow to before dividing?
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How far is stem cell research from being to generate a new organ?
How far are we from being able to use stem cell research to generate a sperm, a heart, a liver, and a kidney?
In stem cell research, my understanding is that you must start off with some cell to ...
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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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What are chiasmata?
I have a confusion in understanding what chiasmata are. My ‘NCERT’ book says ‘The beginning of diplotene is recognised by the dissolution of synaptonemal complex and the tendency of the recombined ...
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How do stem cells produce 200 billion new blood cells every day? Does 1 stem cell division result in production of just 1 blood cell or many?
It is given on wikipedia that everyday 200 billion new blood cells are produced in the bone marrow. I want to understand how this is achieved. Does one hematopoietic stem cell's single division result ...
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How can neurons divide without centrioles?
I have read in my studies that neurons lack centrioles. If that is so, then how is it possible that new neurons are added to our brain? Does this have anything to do with memory loss?