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Questions tagged [eukaryotic-cells]

Organisms whose cells contain organelles, complex structures enclosed within membranes, in particular a nucleus.

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DNA replication - how many times and when does it occur?

I’m currently learning about DNA replication in both prokaryotic and eukaryotic cells. And my lecturer has mentioned that replication is a once in a lifetime activity. And I’m not sure what this is ...
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Chemical composition of human nucleoplasm?

I'm working on a computer visualisation of the inside of a human cell nucleus (embryonic stem cell for now if it makes a difference) and want a good approximation of the chemical composition of the ...
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How is it possible for a cell to have hundreds or thousands of microtubules?

A centriole has only 9 sets of 3 microtubules thus giving 27 microtubules per centriole, or 54 microtubules per centrosome. The maximum number of microtubules in a cell due to centrosomes will thus be ...
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L-selectin in white blood cells

The white blood cells' function is mainly to fight off external antigens. However, another one of its traits is its ability to bind to vascular endothelial cells with the help of L-selectin. What is ...
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Why are the cells the smallest unit of life? [closed]

Please Tell me why the cells are called the smallest unit of life. According to me I know that they are called so because they are smallest entity which is alive that is they show the properties of ...
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454 views

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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Seeing essential vacuole-oils with microscope

Background As an experiment of chemistry we will distille organic volatile compounds with water vapor distillation. The vegetal (clove) is on the image below. Question As this compounds are stored ...
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What flora existed during the last ice age, before the Anthropocene epoch?

Somehow there isn't a single source on the internet that can simply answer a decent amount of what species or even genus of flora existed during the ice age. Obviously only an advanced computer ...
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Neutral genetic mutations in eukaryotic cells [closed]

Why are most mutations in eukaryotic cells neutral? i.e. have no effect on the phenotype.
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129 views

Is this sentence about RER correct on Wikipedia?

While studying about Endoplasmic Reticulum on Wikipedia, I came across this sentence A ribosome only binds to the RER once a specific protein-nucleic acid complex forms in the cytosol. This special ...
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Why do mitochondria have a phospholipid bilayer?

So, a thought came up and I couldn't find all that much info online, so I thought I'd ask some professionals here! The endosymbiont theory states that: mitochondria came to be ingested by bigger ...
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578 views

Why is translation so much faster in prokaryotes than eukaryotes?

Prokaryotes perform transcription and translation much faster than eukaryotes. If memory serves, a single 70S prokaryotic ribosome can incorporate around 20 amino acids per second, whereas the 80S ...
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Are there differences between the activation proteins of Eukaryotes and those of Prokaryotes

I'm in BIO 203 (for reference to my skill level), and I noticed the textbook makes a whole section out of transcriptional activator proteins, their function and applications in eukaryotes, but in ...
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What organelles are in an onion cell?

I was wondering what organelles are in an onion cell, because, based on the labs we are doing in my biology class, I only saw a nucleus and cell wall. My friends and brother say there are all the ...
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109 views

Why is the rough ER necessary to make extracellular proteins? [closed]

It is my current understanding that free ribosomes synthesise proteins to be used inside the cell, and the rough endoplasmic reticulum is necessary to make proteins that are to be secreted by the cell....
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How do you differenciate between the eukaryotes and prokaryotes?

I wonder how we differentiate between the eukaryotes and prokaryotes. Eukaryotes: Eukaryotes (also spelled "eucaryotes") comprise animals, plants, and fungi—which are mostly multicellular - as ...
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Difference in multicellularity between prokaryotic and eukaryotic organisms

As most prokaryotic organisms are single-celled, and in eukaryotic organisms this is the reverse, is there some evolutionary advantage that led to these features evolving? Or is it purely the fact ...
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What attaches plant cells to the cell wall?

In animal cells integrins span the plasma membrane and attach the cell membrane to the extracellular matrix. I was wondering how are plant cells attached to the cell wall? Is it just the middle ...
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Plants and Specialised Cells

Would the number of specialised cells in a leaf decrease if the plant was located in a shadier area? I thought it would decrease as there would be no need to store as much food in the plant and that ...
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103 views

How Mitochondria differs from Prokaryotes(probably regarding energy production)? [closed]

In other words, what evolutionary advantage is offered by mitochondria to eukaryotes(probably regarding energy production), which prokaryotes themselves cannot evolve or do?(here I am assuming that ...
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602 views

How much DNA do humans have?

A normal human body has approximately 3 billion base pairs. Given that humans have 10 trillion cells, how is that the number of base pairs of DNA is less than the number of cells? It can happen only ...
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295 views

What is the function of multiple nuclei in syncytial cells?

What is the function of multiple nuclei in syncytial cells specially in protists with cilia? Is multiple nuclei a special characteristics of only ciliated cells?
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How does repair take place on leading strand in Eukaryotes?

I am currently reading molecular biology of the gene by Watson to develop understanding for the mechanism of replication and repair. Under the topic mismatch repair of DNA they mentioned that ...
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747 views

Haploid eukaryotes?

I was wondering whether there are any eukaryotes which never have a diploid phase. I can't think of any. Fungi have diploid stages, and I know any sexually reproducing organisms will have at least ...
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How did the nucleus of eukaryotic cells evolve?

What is/are the most popular theory/theories on how the nucleus evolved? I know mitochondria came from alpha-proteobacteria, chloroplasts from cyanobacteria and that eukaryotes evolved directly from ...
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Did the Great Oxygenation Event also cause a mass extinction?

It's usually assumed that the Great Oxidation Event around 2.3 billion years ago caused a great extinction of anaerobic life on earth. However, I was reading Nick Lane's book, The Vital Question, and ...
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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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Why are plant cells rectangular and animal cells spherical shaped?

Is that because the plant cells have cell walls and animal cells don't, or is there a function performed by the different shapes? Perhaps round shapes assist the movement of cells?
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Do eukaryotes assimilate DNA that is floating in the extracellular membrane?

Prokayotes, which replicate primarily using binary fission, don't get much genetic diversity. For this reason, they take in any genetic material they encounter, in a gambit to help them better adapt ...
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359 views

Why did eukaryotic cells develop? [closed]

If eukaryotic cells can survive in extreme conditions, then why are their still prokaryotic organisms?
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What determines whether the maternal or paternal allele is expressed?

I am taking cell biology and have this question: During the process of gene expression, it is possible to express either the maternal allele or the paternal allele. When and how is the determination ...
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2k views

Chemoautotrophic eukaryotic cells?

There are heterotrophic prokaryotes, and there are autotrophic prokaryotes. In the autotrophic prokaryotes category, there are photoautotrophic prokaryotes and chemotrophic prokaryotes. Are there ...
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2k views

Could viruses be used as antibiotics?

Could we use viruses that only affect bacteria to act as antibiotics? The more bacteria, the more times the virus divides, so the stronger it gets. Is this practical?
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Linear and Circular DNA

So school has taught us that eukaryotes have DNA that is linear and inside of a membrane - called the nucleus. And that prokaryotes have circular DNA that is free floating inside of the cell. We ...
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880 views

How stable is linear DNA transfected in eukaryotic cells?

I would like to know, with references from the literature, what is the half life of a linear dsDNA transfected in a mammalian cells. For example, if I transfect human cells with a PCR product (500-...
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How to grow fibroblast colonies from single cells?

I need to establish a cell line starting from single cells seeded on a 96 wells plate by a FACS sorter. The cells I am using are human fibroblasts RPE-1 cultured in F12 medium supplemented with 10% ...
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Pros/cons: linear vs. circular DNA [duplicate]

Why did Eukaryotes evolve to have linear DNA and not circular like Prokaryotes? What are the pros and/or cons?
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Trying to differentiate between the three muscle tissues with small pictures

For an assignment I have to differentiate the three types of muscle tissues in these three pictures . I'm having difficulty seeing the striations and branches etc. because the pictures are so small. ...
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334 views

What is most simple eukaryotic genome?

Expressed in number of Base Pairs or Bytes, about how large is the simplest eukaryotic genome? How much of this is 'junk-DNA' (non-coding)?
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Are HeLa cells edible?

I'm curious if HeLa cells are intrinsically poisonous or dangerous to ingest. My understanding is that some of the contamination in HeLa cells such as HPVs are not readily expressed. I have no plans ...
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Asexual reproduction and Telomeres

Many eukaryotic organisms like yeasts, hydras , planarias, plants etc reproduce asexually. Replication of End of linear DNA pose a limit to the number of cell divisions. My question : Do asexually ...
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The Origin of Mitochondria

For a long time I've just accepted, because it is just what everyone told me, that mitochondria became organelles in the cell when they were "engulfed" by another cell which acted like it's host. This ...
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Is episome a plasmid or a virus?

A plasmid is a small DNA molecule that is physically separate from, and can replicate independently of, chromosomal DNA within a cell. In general, in eukaryotes, episomes are closed circular DNA ...
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What is the best way to express two proteins in a mammalian cell?

I have two proteins and I will be preparing a vector with both genes for stable transfection. Each protein will have their own promoter and I will use piggyBac vector to insert a single cassette with ...
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1answer
443 views

Does GTP-γS (GTP gamma S) bind all GTP-binding proteins?

I've just read an article Rab10 GTPase regulates ER dynamics and morphology - Nature Cell Biology 15, 169–178 (2013) doi:10.1038/ncb2647. In this paper, to identify Rab proteins in ER, first they ...
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2answers
750 views

Do any cells change in size or mass as mammals grow?

That is to say, are there cells that, between infancy and adulthood, get larger? Or is all growth done entirely via cell division? I'm wondering if it is safe to assume that the approximate number ...
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3k views

Do adipose cells divide in adults?

I have a dim recollection of having heard that when humans gain weight, adipose cells just get larger, rather than dividing. True?
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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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Why aren't mitochondria and plastids considered symbiotes of eukaryotic cells?

Mitochondria and plastids have their own DNA, their own membranes, and their reproduction is not tied to the reproductive cycle of the host cell. However, they are considered to be organelles rather ...
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What metabolically happens when an egg fuses with the nucleus of a somatic cell

In stem cell biology, it is recognized that embryonic stem cells are transcriptionally inactive for the first 3 days of development. However, during somatic cell nuclear transfer, the nucleus is ...