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.

learn more… | top users | synonyms (2)

5
votes
2answers
225 views

Do changes in an organism's cell modify the genetic information it uses for reproduction?

What I'm actually interested about is whether a modification in one cell during the life of an asexually reproducing organism affects its genetic information? Which cell's genetic information is used ...
1
vote
0answers
30 views

Why can't some organisms match miRNA perfectly to the target mRNA like in plants? [closed]

What causes other organisms to be impaired in making perfect matches like plants do and is there a way to increase matching?
10
votes
2answers
232 views

Why do mitochondria fuse together?

Contrary to all of the textbook images of mitochondria that I have seen over the years, I had just learned that the mitochondria within a cell form a dynamic branching network along microtubule ...
3
votes
1answer
312 views

What happens to the precursor protein's signal sequence after it is cleaved?

Where does this signal sequence "go" after it has been cleaved by signal peptidase and what is its next function?
1
vote
0answers
42 views

Why do restriction-modification systems work?

Some RM systems (restriction-modification systems) are plasmid-borne and are transferred through bacterial conjugation. As you all know, there are two genes in an RM system, the gene that codes for ...
2
votes
0answers
57 views

What is NK-cell compartments?

with respect to the paper: Adaptive reconfiguration of the human NK-cell compartment in response to cytomegalovirus: A different perspective of the host-pathogen interaction What is meant by ...
4
votes
2answers
134 views

Name two reasons why it is impossible to determine a gene's nucleotide sequence from the amino acid sequence of the polypeptide

I can only think of one reason, which is because different codons can specify the same amino acids. However I am having trouble thinking of another reason.
5
votes
1answer
2k views

What is our skin made up of?

Again, it is a basic question. What is our skin made up of? is it made up of many cells arranged in a systematic way or is it just like any layer say of a book?? what is the difference? where is the ...
1
vote
2answers
221 views

The Ancient Kingdom of Monera

Why exactly were bacteria and archaea kingdoms separated from the now unused kingdom of Monera? Aren't they the same? They are both prokaryotes, so what is the difference?
1
vote
3answers
533 views

What is the basic structure of the nuclear lamina

What gives the nucleus its shape is a mesh of intermediate filaments called the nuclear lamina. It forms an interface between the chromosomes and the inside of the nuclear envelope. If these ...
4
votes
1answer
104 views

Do cell membranes have more phospholipids in one layer than in the other?

Assuming the cell membrane to have a spherical shape, geometry tells us that the area of the inner leaflet is smaller than the area of the outer due to the difference in radius between them. Does this ...
1
vote
0answers
10 views

Plants and animals ability to survive polypoidy conditions [duplicate]

In mammals the condition polyploidy produce something euphemistically termed "general developmental disruption" ,practically speaking this means system meltdown which happens very quickly. There is ...
4
votes
0answers
37 views

Procedure for doing western blot [closed]

I am writing a step by step guide for doing a western blot for a class. It is intended for any one with basic Biology lab skills. I am hoping people will review my draft and give feedback on how to ...
2
votes
1answer
59 views

Detailed mechanism of the cause of diabetes mellitus type 1?

I have read in some texts that diabetes mellitus type 1 is caused by degeneration of beta cells due to our body's own immune reaction.Is it true? Can you explain further how are such types of immune ...
0
votes
1answer
32 views

How did multicellular life evolve? [duplicate]

I can imagine several specialized unicellular beings collaborating. But how does life get from that point to a unique pluricelular being that reproduces into another pluricelular being?
3
votes
2answers
1k views

Can cell exist without Ribosomes? [closed]

Last night I came across a question that goes as follows:- Cells cannot exist without a) cell wall b) cell membrane c) mitochondria d) ribosomes I am getting confused with option B and option D ...
8
votes
1answer
509 views

What is the difference between organelle membranes?

Cells and organelles are contained in lipid bilayers. I'm particularly interested in eukaryotic organelle bilayers and the biophysicochemical differences between them. Many papers assume a ...
1
vote
3answers
102 views

Can a portion of human skin cells be modified in some way to generate light? [closed]

I have come across some species of living organisms who are able to emit light at whim. Can that ability be incorporated into a portion of human skin (a specialized tissue)?
5
votes
1answer
15k views

Chromosome and chromatid numbers during cell cycle phases

A diploid cell in G1 has 6 chromosomes. How many chromosomes and how many chromatids are present in each of the following stages? Here is what I am guessing G1: 6 chromosomes ; 6 chromatids G2: 6 ...
1
vote
1answer
871 views

What is the present tense verb form of apoptosis?

For example, if I want to say something along the lines of "this signaling pathway causes a cell to go through the process of apoptosis", but I want to shorten the phrase "go through the process of ...
3
votes
1answer
123 views

Expression/Mechanism of ROR1 in healthy tissue

ROR1 is currently under investigation as a therapeutic target for cancer (1). A number of studies show different cancers may have their metastatic potential reduced, or become apoptotic through ...
1
vote
1answer
192 views

What is Trypsin? [closed]

I am currently helping a PhD student in his research lab. We have been using Trypsin for the past couple of weeks but I am unsure of its purpose. I was wondering how Trypsin functioned and what it was ...
8
votes
1answer
2k 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 ...
3
votes
1answer
82 views

What are senescent cells doing in our bodies? [closed]

I'm reading a paper that mentioned the elimination of senescent cells delays aging. I'd like to receive more information about it. The Baker study published in Nature demonstrates that targeted ...
5
votes
3answers
460 views

What advantage does an enzyme serve over catalysis by the addition of heat energy?

I understand that an enzyme lowers the activation energy, allowing the reaction to run faster, however I am not sure, how it may be favorable during the addition of heat energy. Wouldn't that lower ...
1
vote
1answer
64 views

How can I isolate live Wolbachia endosymbionts from Drosophila [closed]

I am interested to culture Wolbachia bacteria in cell line.
7
votes
1answer
54 views

What is a positive epitope fragment

What is a positive epitope fragment? I found one paper on the subject: COBEpro: a novel system for predicting continuous B-cell epitopes by Michael J. Sweredoski and Pierre Baldi
4
votes
1answer
724 views

What kinds of cells does human saliva contain?

I have heard that our saliva contains cells. What cell types can be found in human saliva?
2
votes
1answer
242 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?
3
votes
1answer
174 views

Which of the two mitochondorial membranes relate to bacteria according to the endosymbiotic theory?

I seached for endosymbiotic theory in Wiki and I found this about endosymbiotic theory: Symbiogenesis, or endosymbiotic theory, is an evolutionary theory which explains the origin of eukaryotic ...
4
votes
1answer
252 views

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. ...
1
vote
1answer
35 views

Why does a tumour's genome change depending on the environment?

According to the book "Primer of The Molecular Biology of Cancer" by Vincent, Theodore and Ateven, the tumour cell is changed depending on its environment. performed genome-wide analysis on three ...
5
votes
1answer
168 views

Can methylation of a promoter induce gene expression in some rare cases?

Can methylation of a promoter induce gene expression in some rare cases? I've read somewhere that methylation of an intron can induce gene expression (eg. Igf2). How is that even possible? Thank ...
9
votes
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 ...
7
votes
1answer
346 views

Is this a grass cell?

I found this picture online claiming it was a grass cell. Clearly it is a cross section image but I was hoping you could tell me if this is actually grass, or something else if anything.
3
votes
3answers
406 views

why do some cells in the body prefer necrosis to apoptosis as a means of cell death?

There are many programmed cell death pathways, but some cells show a greater preference for some over the other. I'm wondering as to why if necrosis is an inflammatory response that causes damage to ...
3
votes
0answers
44 views

What has to duplicate before cell enters M phase? [closed]

What has to duplicate before cell enters M phase? DNA histones centrosome mitochondria (any other organelles?) condensins (not sure?) have I forgotten anything? Thank you in advance!
3
votes
3answers
315 views

How do we look inside the cell?

My sister is in 9th grade biology and her teacher avoided answering the question of how we actually study the inside of a cell. I haven't taken biology in a while but I'd like to give her an answer. ...
3
votes
0answers
227 views

How to prevent e coli from clumping (for FACS)?

I'm performing FACS on e coli, but the cells are clumping together so each event is multiple cells. I ran a control where I had one flask of e coli expressing GFP, and one flask expressing RFP. Run ...
7
votes
1answer
114 views

What were the first neural systems like?

I'm curious about the origin of the neural network. I'm thinking perhaps once life evolved beyond the single cell organism, it needed a simple neural network to coordinate those cells, and cell ...
3
votes
0answers
48 views

Why is ATP the main nucleoside triphosphate used to exchange energy? [duplicate]

Out of all of the nucleoside triphosphates what makes ATP the most used? Is it its structure? The amount of energy it contains? Why is GTP not used as much? What is the deal with the other nucleoside ...
7
votes
1answer
159 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 ...
2
votes
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 ...
3
votes
2answers
107 views

Energy metabolism in Cancer cells

The TCA cycle intermediate Isocitrate dehydrogenase commonly undergoes point mutations in cancers. This allows IDH to reduce a-Ketogluterate to 2Hydoxygluterate, causing a reduction in pVHLs ability ...
4
votes
1answer
131 views

What effects does being cryogenically frozen have on a person's body? [closed]

I'm wondering what effects are known to happen to a person's cells when a person is cryogenically frozen, especially those that need to be overcome in order to "bring them back to life." From a ...
12
votes
3answers
2k views

Does a man contain all the genes needed to make a woman?

This question is brought on by a Sci Fi novel I am thinking about writing. The plot device involves a colonist in charge of building a population on a new planet who loses his supply of embryos and so ...
0
votes
1answer
189 views

Why do some cells like myofibrils have multiple nuclei?

I see that myofibrils (muscle cells) contain not one, but multiple nuclei. Why is this so? Do all the nuclei participate in cell division?
7
votes
1answer
1k views

Are pulp cells (in oranges) normal plant cells?

Does a pulp cell contain all the elements that a 'normal' plant cell contains? I've searched for an hour to find more information about this but couldn't find anything useful. Is the pulp cell the ...
0
votes
1answer
155 views

What is the second phase of photosynthesis?

I really want to know what the second phase of photosynthesis (in the dark) is. I have a fair understanding of the first cycle where molecular oxygen is generated under the influence of light, but I ...
0
votes
1answer
944 views

When do the spindle fibers attach to the chromosome

At what phase does this occur in mitosis (or even meiosis); some text books say prophase while others say metaphase.