1
vote
2answers
273 views

Microscope scale bar

In some microscopic images, there is a bar scale at one of the corners or near a specific object. How are they added to the images? Does the slide have some markers, or are they digitally added? If ...
0
votes
0answers
15 views

Why low variant frequency in exomeseq data (ANNOVAR)?

I've got an annotated ANNOVAR file with 300.000 nucleotide variants of 4 genomes. There's one thing I don't understand when looking at the data: Why are the variant frequencies so low in comparison to ...
1
vote
1answer
82 views

History: Building a “Phylogenetic network” of famous evolutionary biologists [closed]

Seems like many of the famous evolutionary biologists are somehow related to each others. For example (and I might be mistaken), Ronald A. Fisher was mentored by a descendent of Charles Darwin. Joe ...
5
votes
1answer
263 views

Influence of eating at late night on sleep

I have often heard the saying that one shouldn't eat a mountain of food because blood will go to the stomach and it'll be difficult to sleep well because the stomach can't rest at night. I see that ...
4
votes
1answer
157 views

How could I identify whether given RNA-seq data is paired end or single end

I need to have a RNA-Seq dataset and therefore, I've visited the following site NCBI-geo C. Elegans In the Supplemantary file part, I clicked the SRP/SRP051/SRP051702 ftp and downloaded sra file. ...
1
vote
1answer
2k views

What's the difference between stabilizing selection and balancing selection?

I came across these terms in Darwin's "Origin of Species" and I wasn't sure what the difference is.
0
votes
1answer
90 views

What does this mutation notation mean: MAP2K41161fs*12

I received a report that had a mutation notated as: "MAP2K41161fs*12". I'm used to seeing this sort of thing: BRAF(V600E) or BRAF(T1799TA). Can someone tell me how to interpret "MAP2K41161fs*12" ?? Is ...
3
votes
5answers
1k views

Does any animal species have two sexes and more genders?

Does it exist any animal species that have two sexes and a kind of different internal diversification in two genders or more? I mean no something like different-task-based diversity but something ...
9
votes
2answers
45k views

What is the function of the RNA primer in DNA replication?

During DNA replication, RNA primase puts an RNA primer in the lagging strand. What is the function of this RNA primer? Why can't the enzymes put DNA fragments directly?
4
votes
1answer
179 views

Lentivector biosafety

Lentivectors are widely used in molecular biology, most commonly to transduce in a stable way a desired gene. These vector system takes advantage from the ability of viruses to introduce their own ...
4
votes
2answers
263 views

How to conceptualize the action potential?

In my AP Biology class, we were taught that action potentials are not electrical impulses in the same way current travels through a wire. Rather, we were taught that action potentials are changing ...
1
vote
2answers
159 views

Trying to understand the big picture behind DNA sequencing, alignment and searching

I'm about to start a bioinformatics research project but I haven't any biological background. I know my project is in regards to a performance analysis of DNA sequencing and searching "weapons" like ...
41
votes
4answers
3k views

What exactly are computers used for in DNA sequencing?

I've thoroughly read the Wikipedia article on DNA sequencing and can't get one thing. There's some hardcore chemistry involved in the process that somehow splits the DNA and then isolates its parts. ...
1
vote
0answers
61 views

Drosophila biarmipes gene annotation, transposable element?

When doing an annotation of a contig31 of Drosophila biarmipes genome, the gene predictions(in orange, red, green, tan, blue, brown, and gray) picked up numerous possible genes in the area circled in ...
2
votes
1answer
225 views

How do you convert mtDNA sequences in FASTA to FSTAT format?

I've got control region sequence data from a population of shark and I'm looking to convert this from FASTA to FSTAT in order to calculated the effective population size of females. The software I ...
0
votes
1answer
120 views

Mutations/deletions with CRISPR

I need to stop some protein from being active and searching for some universal way to do so. In mammalians. With CRISPR it is possible to knock-out the entire gene. But it's a little complicate ...
2
votes
1answer
74 views

How is protein cavity centre related to binding?

I am confused and I have the following questions: 1. What are (in the context of article below) protein cavity centres? 2. How are they related to binding? (Automated identification of protein-ligand ...
0
votes
1answer
93 views

Genetic notations

Genetic testing revealed these two mutations (hypothetically): IVS11+6G>A and IVS11-4G>A Could you please explain every part of this notation, especially "+" and "-" signs.
1
vote
3answers
744 views

How does frame-shift mutation not absolutely ruin the organism?

I'm a bit curious as to how frame-shift mutation works. If you shift one amino acid towards another. How does this not affect the entire chromosome? Wouldn't this mean that the organism would be ...
7
votes
1answer
232 views

Why do only humans commit suicide? [closed]

Why is it that only humans commit suicide? Many animals do 'brave' things to protect their children or family, and some male spiders sacrifice themselves so that they can impregnate the females. ...
3
votes
2answers
46 views

Macrophages and what they consume

Do macrophages in the dermis consume any foreign invader to the body, or simply pathogens and cellular debris? For example, would macrophages consume vitamins or medications injected into the dermal ...
2
votes
1answer
114 views

Are there any examples of how to apply evolutionary models?

Apologies if this question it too open-ended; evolutionary biology is not my primary field. I have been reading a lot about the use of statistical mechanics in analyzing evolutionary dynamics. As an ...
1
vote
0answers
38 views

What will happen to transcription if histone acetyltransferases are removed from a eukaryotic cell?

If HATs are destroyed in a eukaryotic cell, how will gene expression level be affected? Will all gene expression be affected or just be slowed down and most gene will still be expressed?
1
vote
1answer
155 views

(Genetics) Is a silencer the same as gene silencing (heterochromatin)?

Is silencer the same as gene silencing? I know that gene silencing refers to those heterochromatin concentrated at the telomeres or centromere. It is also related to methylation. But what about a ...
0
votes
1answer
150 views

Can the Staph streak method be used for culturing Neisseria on blood agar?

What I learned in class: Normally chocolate agar is needed to grow Haemophilus and Neisseria. The Staph streak technique can be used for culturing Haemophilus on blood agar by allowing the Staph to ...
7
votes
1answer
133 views

Chromosome picture, how to interpret?

In this guide i was reading for annotations, there is a diagram of chromosomes of D.mel, I am confused as to why the chromosomes are all attached to one another, is this picture taken in a certain ...
1
vote
0answers
28 views

Linkage Disequilibrium in GWAS

I see a lot of studies on GWAS not filter out for linkage disequilibrium or even make the slightest mention of it. Why is this the case? I would imagine that you want to keep SNPs that are only in ...
3
votes
0answers
77 views

Neural coupling between Pinsky-Rinzel (reduced Traub) neuron with a Wang-Buzsaki neuron?

I have read two papers related to modeling neurons. The first one is the paper by Pinsky and Rinzel and the second one by Wang and Buzsaki. The first mentioned neuron model is a excitatory neuron ...
0
votes
0answers
37 views

Some kind of better oxygen-transport protein or something… Can you help me find it?

I remember reading about artificial or man-made, oxygen-transport protein that is somehow an improvement on hemoglobin, and that it is possibly immune to sickle-cell anemia, or something... But I ...
6
votes
3answers
126 views

How animals know which is carnivorous and herbivorous?

Deer ran away from tiger or cheetah, but not from giraffe or zebra. where did deer learn this? How animals know which is carnivorous and herbivorous?
4
votes
3answers
206 views

Gametes of two different species

I always wondered why gametes from two different species dont fuse together to form an offspring. eg a donkey (sperm) and a female dog (egg) I know this is not possible but I'm just curious.
4
votes
2answers
279 views

Proteins that give color (without fluorescence)

Is there proteins that have strong color, that could be seen without the need of UV and with naked eyes (with white light) - in mammalian cells? Searching for reporter, something like GFP, but that ...
10
votes
2answers
9k views

Why is PEG important for efficient yeast transformation?

One way to do an yeast transformation is by using lithium acetate, a single-stranded carrier DNA, and PEG (1). I was wondering why is the polyethylene glycol important for the efficient ...
3
votes
0answers
86 views

Is the number of stamens always 9 for geranium?

We are studing in class the reproduction of plants. We start the lesson by observing some components of flowers, it was the Géranium. First of all we start counting the number of sepals , petals and ...
1
vote
0answers
38 views

What is a “NuMA protein”?

I just got out of a lecture on mitosis and this part was incredibly confusing. After searching my textbook it doesn't cover it that well either. The professor mentioned a NUMA protein that is ...
1
vote
1answer
68 views

Limited space for animals - how is that bad?

I am writing an English paper wherein I have to appeal for change in the way humans treat wildlife. I was initially given a situation wherein I took a ferry in a certain area and saw a dead baby ...
1
vote
1answer
84 views

How does inbreeding depression cause infertility?

My textbook states that repetitive self-pollination in the plants cause inbreeding depression which causes infertility thus plants develop techniques called outbreeding devices to encourage ...
1
vote
0answers
207 views

Importance of organic chemistry in biochemistry/molecular biology? [closed]

I'm halfway through my biochemistry and molecular biology degree in Australia and i'm concerned about a lack of organic chemistry. My friends studying biochemistry back home in Canada take units upon ...
0
votes
0answers
67 views

Determining the percentage of the query of an alignment from a BLAST output

Given this BLAST output, how can I determine the percentage of the query sequence in the alignment? I know that it's also referred to as 'query cover' but I can't seem to find anything online that ...
0
votes
1answer
85 views

How does the partial pressure of oxygen affect mental focus?

On this Wikipedia page it says that lower oxygen levels can cause light-headedness. Is there evidence that higher partial pressure of oxygen can improve mental focus?
4
votes
1answer
54 views

Multistability in the lactose ultization network

Reading the paper here, I'm confused about the production of figure 4d. The method of production is detailed in the supplementary information under the heading "Theoretical phase diagram". ...
0
votes
1answer
49 views

Do restriction enzymes on read 3' to 5'?

Every chart of palindromic restriction enzymes I've seen lists their restriction sites from 5' to 3', something like this: EcoR1 cuts GAATTC between the G and A: 5' NNNGAATTCNNN 3' --> ...
0
votes
0answers
81 views

Does embryonic development mimic (partly at least) the evolution of organisms on earth?

What do we know about the forces/mechanisms which lead to this seemingly "fast forward" evolution stages of the embryo? What are the theories dealing with this idea?
11
votes
3answers
11k views

How does sodium in one's diet affect blood pressure?

Due to high blood pressure, my doctor has recommended I go on a low-sodium diet. So, that got me wondering what it is about sodium that drives this recommendation? What does sodium do to a body ...
16
votes
1answer
617 views

Why does mint oil feel cold on the skin?

When putting (japanese) mintoil on the skin it produces a cool feeling. You can experience this, when adding it to your bath or using a spray with mint oil on your skin. The cool feeling occures ...
5
votes
2answers
180 views

A doctor might give bicarbonate (HCO₃¯) to a patient who is breathing very rapidly. What is the doctor assuming about the patient’s blood chemistry?

The answer is: The doctor is assuming that the rapid breathing is the body’s response to low blood pH. (Source: Campbell Biology) But this answer doesn't make sense. Why would the doctor give the ...
12
votes
2answers
3k views

What is the explanation for the smaller number of tRNA than codons?

Translation, or decoding, of the four-nucleotide language of DNA and mRNA into the 20–amino acid language of proteins requires tRNAs and enzymes called aminoacyl-tRNA synthetases. To ...
0
votes
0answers
29 views

Regarding benzoic acid and its effects

One of the users on the chemistry s.e. mentioned that when benzoic acid forms in the body in response to other chemicals it might have a mutating effect on one's DNA. Is this true?
5
votes
2answers
1k views

Why is a slow worm not considered a snake?

Slow worms are considered lizards as opposed to snakes, both are reptiles. Now I get that there are traits that distinguish them (eye lids, ears ...). But snake species themselves vary already quite a ...
1
vote
1answer
188 views

What causes muscle spasms?

What causes muscle spasms with muscles that are not in the heart ? Could it be some sort of stimulus overload that causes a massive contraction?

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