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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462 views

How can I create a microcapillary for manipulation of single cells?

i'm working as a diy bio. I'm finding a way to create a micro glass capillary for picking up single cells. I see this video on youtube and would like to know what is the minimum I/O diameter if I pull ...
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1answer
63 views

What's the difference between tumor cells and host cells? [closed]

When you talk about cancer, is there a difference between tumor cells and host cells ? What is the role of immune cells ? in a nutshell ?
2
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1answer
204 views

How long can a human neuron live outside the body in a controlled environment?

Have there been any experiments that have kept neurons alive (stationary), without preserving methods such as freezing? If yes, then how long were the cells kept alive for?
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0answers
19 views

Mechanism of Octoxynol-10 as a preservative in vaccines

I noticed that the Fluarix Quad flu shot this season contains Octoxynol-10 rather than Thimerosal as a preservative. I am not expert in this area, so I did a Google search of "Octoxynol-10", and ...
2
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0answers
31 views

How do human cells respond to mechanical pressure such as heel contact during walking?

Basically, I'd like to do a full accounting (inventory, assets, liabilities) of a human cell under mechanical pressure. For example, if in steady-state, does the cell consume more or less energy ...
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0answers
13 views

Heteroplasmy in different tissues

I have only started reading the substantial body of research on heteroplasmy. I was curious if anyone knew of attempts to measure the somatic cell mtDNA mutation rate, to see if it differed from the ...
17
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2answers
45k views

How many human cells are there in our body, on average?

How many human cells are there in our body, on average? Wikipedia says 1013: Bacterial cells are much smaller than human cells, and there are at least ten times as many bacteria as human cells in ...
0
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0answers
26 views

What does high CD4 level means?

I was going through this webpage and I found the following lines: We hypothesised that despite unimodal distribution of CD4 co-receptor on naïve CD4 T cells they are not homogenous in their ...
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0answers
21 views

What are some similarities between chloroplasts and cyanobacteria thai are evidence for endosymbiosis?

Four or five would be perfect. I am a high school IB Biology student and can't find information on this in simple words for my knowledge level.
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0answers
23 views

UACC-462 cell culture

UACC-462 is a pancreatic cell line established in the University of Arizona Cancer Center (UACC). The cells are available from ATCC and there is the instruction for culturing UACC-462. M-41 medium. ...
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0answers
18 views

What is the significance of 9+2 arrangement in flagella?

Why eukaryotic flagella have 9+2 arrangement .? What is the significance? a 9+0 flagella should have worked the same way .
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0answers
32 views

How is flagellar movement controlled?

How does a cell control the movement of flagella? Both the rotatory movements and sideways movements helps the cell to move. How are these flagellar movements controlled ? It is through the regulation ...
0
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1answer
46 views

Why is it important to have a restriction point? (G1-S phase control)

Why have eukaryotes evolved to control G1-S phase? Surely if you could control G2-M phase very well, you will not get an excessive proliferation? Thanks for your help.
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2answers
169 views

Does soap kill human cells?

I see many products, particularly hand soap and cleaning products, that claim to kill 99.9% or more of bacteria. This makes me wonder, if the chemicals are potent enough to break down bacterial cell ...
4
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1answer
2k views

Why are red blood cells considered to be cells?

Wikipedia states that a cell is the basic structural, functional and biological unit of all known living organisms. Cells are the smallest unit of life that can replicate independently. It then ...
3
votes
2answers
151 views

How does Cro protein expressed by lambda phage kill its host?

I read that the DNA segment of lambda phage integrated in host DNA could switch between lysogenic state where cI represses the expression of Cro and lytic state where Cro expression takes over and ...
1
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1answer
39 views

Can mexican salamander regenerate any organ?

Mexican salamander or few other species of salamander can regenerate limbs, tail etc. Do they have HOX genes for vital organs like liver, heart, brain, kidney? If brain is damaged, can salamander ...
2
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1answer
99 views

Why is chromatin not condensed during interphase but is in prophase [closed]

Cell cycle goes through three processes: Interphase Mitosis Cytokinesis Why are chromatins not condensed during interphase but instead condensed at prophase of mitosis? What makes them condense ...
2
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0answers
38 views

Lipid-soluble vs. water-soluble substances through the membrane

It’s said that water-soluble substances can enter the cell membrane with less ease than lipid-soluble substances because the former encounters impedance in the hydrophobic region of the phospholipid ...
3
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4answers
185 views

Recommend good conversational books to learn about cell and developmental biology or biochemisty?

I'm an engineer by training and teaching myself the basics of cell and developmental biology. I'm using Scott F. Gilbert's Developmental Biology and Alberts' Essential Cell Biology right now, and they ...
6
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2answers
9k views

Why was the Davson-Danielli model rejected?

According to my textbook, Davson-Danielli's model of a phospholipid bilayer sandwiched between two layers of globular protein was incorrect. The nonpolar protein portions would separate the polar ...
2
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0answers
19 views

What's the purpose of Cdk activity having more than one method of becoming inactive?

Cdk becomes partially active once its bound to cyclin and then gets phosphorylated and fully active once a Cdk-activating kinase (CAK) phosphorylates the partially active Cdk. This fully activated Cdk ...
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5answers
6k views

Why do cell membranes have a lipid bilayer?

Many cells have a cell membrane composed of two layers of lipids, why is it two layers and not just one? What purpose do the membranes serve?
2
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1answer
2k views

Complementarity Determining Regions (CDRs)

Complementarity determining regions (CDRs) are part of the variable domains in immunoglobulins (antibodies) and T cell receptors, generated by B-cells and T-cells respectively, where these molecules ...
4
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1answer
164 views

How can a polar molecule pass through polar channels of proteins in the cell membrane?

To transport a polar molecule through the nonpolar cell membrane, a protein with a polar channel is needed to allow it to diffuse. However, if the molecule is polar and the channel is polar, wouldn't ...
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1answer
89 views

Why do animal cells lack a contractile vacuole?

I was asked why animal cells do not have contractile vacuoles. Other than the lack of need, I don't know what else to say.
2
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1answer
25 views

Can specific B-cells be created in a lab? [closed]

Instead of creating protein sequences, could that stepped be skipped and just have B-cells created to manufacture a particular type of immunity?
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1answer
27 views

Determining the osmolarity and tonicity of a cell

Consider a cell with urea concentration inside being 2mmol/L and outside being 2.5mmol/L. The cell itself is permeable to both urea and water. Ignoring the effect of other osmolytes, A) Urea flows ...
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1answer
24 views

Gene silencing in C. elegans

I am trying to silence the tph-1 (tryptophan hydroxylase) gene in C. elegans using the pLT63 plasmid to check if that particular gene has anything to do with the pharyneal pumping or not. Am I using ...
3
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4answers
111 views

Can general soap kill bacteria?

I have read that general soap can kill bacteria by opening holes in the bacterial membrane. http://questions.sci-toys.com/node/90 However, I found some articles as well saying that it cannot. ...
2
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3answers
2k views

Why do cells vary in shape and function when they have the same genome and the same organelles?

Why do cells vary in shape and function when they have the same genome and the same organelles. For example: why do all cells have nuclei but red blood cell's don't; why can't the cells of a eye ...
2
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2answers
10k views

How do plant cell divide without centrioles?

Most plants do not have centrioles , so What organelle lets them multiply?
3
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1answer
57 views

Purpose of antibody wash

It is common practice after surface staining cells for flow cytometry analysis to wash the antibody out of solution before analyzing a sample. I have tried analysis with and without washing the ...
3
votes
2answers
117 views

Is there a database of cell images?

We're working on an algorithm for processing images of cells, similar to but much more basic than Cell Profiler, and we are looking for a large database of cell images to test our software. Can anyone ...
7
votes
1answer
140 views

What is the mechanism by which lamins regulate gene expression?

The heterochromatin is generally localized at the nuclear periphery (also near nuclear lamina), whereas active genes are preferentially found in the nuclear interior. Children with ...
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1answer
62 views

Is there any possible way to take a DNA test without using blood in humans?

Is there any possible way to take a DNA test without the need to draw blood in humans? Any information will be useful for me.
2
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3answers
71 views

Why are embryonic germ cells considered stem cells?

In a class that I'm taking we were presented 3 types of stem cells. Adult stem cells which come from bone marrow Embryonic stem cells which come from embryos Embryonic germ cells which come from ...
7
votes
2answers
13k views

What is the difference between “dikaryotic” and “heterokaryotic” states in the sexual lifecyles of fungi?

Many fungi undergo a reproductive phase in which more than one genetically distinct nuclei (from 2 separate mating types) is present within the same cytoplasm. In the Ascomycota and Basidiomycota, ...
0
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1answer
36 views

How can rapid growth cancer get nutrients in vivo?

When I was little, before I get into biological studying, I read a news talking about cancer would be totally cured after decades. I still remember that researchers had a theory to claim if they could ...
8
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1answer
1k views

How can Valonia ventricosa cells get so big?

Valonia ventricosa are single celled algae that range between one and few centimeters. In rare cases they can reach sizes exceeding 5cm. They range from grass green, to dark green, and some are even a ...
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0answers
42 views

yeast colonies pulsing out soft fringes against the light

I have no idea about this part of the following text "pulsing out soft fringes against the light". Can anybody explain about it and provide some images, please? Does it mean that these colonies ...
2
votes
1answer
51 views

How can E. coli affect C. elegans expression?

Plasmids can be transferred to E. coli. These transformed E. coli can be fed to C. elegans to silence its gene expression by RNAi. How can E.coli release RNAi to C. elegans? Even if we assume E. ...
1
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1answer
132 views

Are mitochondria alive? [duplicate]

I'm working on an assignment for my IB biology class and some assistance would be highly appreciated. I've read several articles and I still haven't quite gotten the answer I'm looking for. I have to ...
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0answers
32 views

how often do the various organ cells regenerate? [closed]

Is there an Internet source that states how often human organ cells (eyes, kidneys, liver, heart, pancreas, skin, etc.) regenerate? I'm seeking specific data for every human organ.
0
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1answer
56 views

which organelle produce glycogen phosphorylase and why

I know that Glycogen phosphorylase doesn't produce from rough endoplasmic reticulum in liver cell. But almost every proteins such as insulin receptor, serum albumin, and lysosomal enzyme have to ...
0
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0answers
14 views

Growth of Yeast in Different pH Mediums

Will yeast grow better in acidic, basic or neutral mediums? Why? Will the medium affect the growth of yeast? (Yeast cell membrane is semi-permeable).
1
vote
0answers
142 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 ...
6
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1answer
6k views

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
584 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
93 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 ...