5
votes
1answer
98 views

How does the body “know” how to metabolize foreign substances

As a freshman biochemistry major, I find myself befuddled by our body's ability to perform complex chemical reactions to break down foreign substances. I can see how we would evolve explicit pathways ...
3
votes
0answers
35 views

Color perception vs shade perception demo

I can't seem to find one of the best demos I've seen of color vs brightness perception. It consisted of a rotating animation of earth made of red of bright red points on a dark green background. As ...
4
votes
1answer
41 views

Medium for Pseudomonas?

What is a good minimal medium for Pseudomonas bacteria? Do I need different media for different Pseudomonas species?
1
vote
0answers
34 views

Download FunCat Database for Programmatic Access

I am enriching RNA-seq data for the fungus Neurospora crassa and would like to be able to search the genome by functional category, determine similarity of genes by category membership, and any other ...
1
vote
0answers
19 views

What are the main principles of the Bacteriological Code?

Although the Bacteriological Code is an important guideline for taxonomists and microbiologists, describing the criteria for delineating species and higher taxa of the prokaryotes, I, and plenty of ...
6
votes
1answer
140 views

Why doesn't Sanger (fluorescent) DNA sequencing double count nucleotides?

My understanding is that PCR is carried out until a fluorescent nucleotide halts replication. The segments of DNA are fed through the capillary tube based on size, sifting through the segments from ...
2
votes
1answer
52 views

Repair of cloning vector nicks digested with antarctic phosphatase and ligated with T4 enzyme

The vector product obtained by ligation between a vector previously digested with antarctic phosphatase lacks 5' phosphate groups. T4 ligase can ligate it to an insert with complementary sticky ends ...
1
vote
0answers
56 views

How does anxiety cause chest pain?

An acute instance of anxiety can cause a sudden sharp chest pain for a very brief period of time. What is the mechanism behind anxiety leading to chest pain? Is the pain coming from the heart ...
2
votes
2answers
103 views

Downloading specific yeast genes in an automated manner?

I have 6 genes of Candida albicans yeast namely orf19.723, orf19.5908, orf19.610, ...
5
votes
1answer
59 views

About radiation therapy

With radiation therapy, could some of the radiation used cause new mutations in non-cancerous cells that are near the tumour that is being irradiated? If so could these new mutations lead to new ...
5
votes
1answer
96 views

Is funnel web spider venom poisonous?

Does the venom of the Sydney funnel web spider have to be injected into the bloodstream to have an effect? If the venom was swallowed (e.g. if a spider was eaten), would it still have an effect? Or ...
5
votes
2answers
95 views

Cytochalasin B in cell movement

In an experiment by Pollard, T.D. and R.R. Weihing, amoeba cells injected with Cytochalasin B were inhibited of movement, while the control group amoeba cells did move. A hypothesis was made that ...
3
votes
2answers
6k views

What causes muscles to generate heat on contraction?

I'm curious what the exact cause is of dramatic heat generation that comes along with muscle activity. Can anybody explain this in understandable language?
6
votes
1answer
110 views

When are a female's eggs created?

Since a human woman is born with a set number of eggs, and meiosis is the process by which sex cells are produced, would meiosis in a woman happen before she is born or soon after she was born? If ...
3
votes
1answer
278 views

What does the empty space in the bamboo stem do?

Is the empty space inside a bamboo stem a xylem? And why is the space so large?
5
votes
4answers
1k views

What is SDS PAGE gel polymerization time?

I am working on 20% SDS PAGE. I want to know optimum polymerization time for 20% resolving gel and 6% stacking gel. If I increase the time then would it affect the band pattern?
5
votes
3answers
382 views

In what sense is the “histone code” a code?

Since I started learning about molecular cell biology, I have witnessed an increasing amount of attention to this thing called a "histone code." However, unlike the central dogma of molecular cell ...
2
votes
1answer
46 views

How are lesions in the RNA corrected?

I quite understand why thymine is present in DNA. So we can mark it out where cytosine undergoes a reaction and is converted to uracil. Then we can repair the DNA. But how can we make that out in RNA ...
3
votes
1answer
883 views

Why does our voice change when we get affected by cold or cough?

Why does our voice change when we get affected by cold or cough? I observed the voice change thing in so many people including me.
0
votes
1answer
355 views

Why are some vegetables/fruits seasonal?

How does the mango tree perceive the summer season, so tree starts producing the fruits? Every tree requires sunlight to grow but what limits the production of fruits to a certain season? For ...
1
vote
1answer
50 views

Double use of ATP in relaxing myosin & active transportation of calcium?

Is the ATP molecule which is bound to the myosin head for relaxation of the muscle (i.e., to break the cross bridge) also utilized for active transport of calcium to the sarcoplasmic reticulum during ...
2
votes
1answer
1k views

What is difference between breed, variant, subspecies and species?

What is the difference between breed, variant, sub-species and species? Are there any similarities between sub-species and sub-population of a region?
0
votes
1answer
139 views

Can someone help me analyze this article? [closed]

I need to read this article — "Beyond the rainbow" by Marie-Claire Koschowitz et al., for an exam. Following are some questions for which I could not figure the answer out after reading. 1) Why ...
10
votes
2answers
1k views

How is DNA Read

Little odd question here. I was told that DNA was read in groups of three. Assuming this, my question is: Which way would better describe how the DNA is read. (123)456789 to 123(456)789 to ...
4
votes
1answer
99 views

Potential to destroy viruses using prions? [closed]

Could a prion be used to sufficiently deform a viral protein in order to make the virus it is a part of incapable of reproducing? For example, take the common cold's VP1 protein and turn it into a ...
1
vote
3answers
224 views

Evolutionary chronology - if any, which species have evolved in the last 100 years

I heared somewhere, I cannot remember where, that there has not been an evolution observed in our lifetime. In life science class, right at the start, we was doing the usual MRSGREN (how to tell if ...
1
vote
0answers
138 views

Blood type frequency given probability

I have calculated the probability that any child will have a particular blood type from both the genotype level and the phenotype level assuming the human ABO Rh system is followed. Here are the ...
17
votes
2answers
611 views

Why should a tumor look like a crab?

Origin of the word "cancer" The disease was first called cancer by Greek physician Hippocrates (460-370 BC). He is considered the “Father of Medicine”. Hippocrates used the terms carcinos and ...
2
votes
1answer
69 views

Will gene mutations give rise to a protein that is shorter than the full length protein?

What is the relationship between deletion or insertion of nucleotide in the gene sequence and the protein's length that is coded out from the mutated gene?
1
vote
3answers
374 views

Are domesticated animals really “more intelligent,” or is that a myth/misunderstanding?

Often do I hear people speaking of how the domestic house cats are more friendly, less ferocious, less savage-like, and smarter and/or than their distinct but equivalent feline-species friends, like ...
4
votes
1answer
128 views

What is the name of this plant (see pic)?

This plant was found growing in Colombia.
6
votes
1answer
81 views

Can dolphins actually communicate linguistically?

Humans use "language." By language, I mean the thing I am using right now to talk to you. I know dolphins and orcas have very complex communication systems and also seem to process linguistic and ...
8
votes
1answer
155 views

Why do humans hear better between 2kHz and 5kHz?

I've recently seen the following image: Source: https://commons.wikimedia.org/wiki/File:Hoerflaeche.svg Translation (from German): The upper boundary (Schmerzgrenze) is where it starts to hurt ...
6
votes
1answer
81 views

Can anyone identify this chrysalis? (Identified)

It's about 5 or 6 cm long. It's on the outside (north facing) wall of my garage about a metre above ground level. Photo taken in Thailand near Hua Hin (about 12N 100E) in December 2014.
1
vote
1answer
43 views

Coniferous trees in temperare rain forests

In temperate rainforest, the dominant plant form is often coniferous trees (source). However, coniferous trees are also the dominant plant form in a very different climate and form a different biome ...
7
votes
2answers
108 views

Can the eye distinguish between pure and composite colours and how do we measure this?

Red light plus green light makes yellow light. Suppose I shone a pure red light, say 650nm, onto the same spot as a pure green light, say 550nm. The eye sees this two-peak spectrum as yellow. This ...
1
vote
1answer
50 views

Specialist evaluation for people aged under 40 years with stage 1 hypertension

Reading the NICE clinical guideline for Hypertension it says... For people aged under 40 years with stage 1 hypertension and no evidence of target organ damage, cardiovascular disease, renal ...
1
vote
1answer
92 views

Is there a rule for the annotation of the basepair or gene locus origin in bacterial genomes?

Since all bacteria have one circular chromosome, there is no designated origin to start the systematic gene locus numbering. Therefore, what is the rule to start the numbering at a particular point ...
1
vote
0answers
99 views

How do I import FASTA files into Haploview?

I'm trying to produce a haplotype network and so have decided to use the software haploview. However I'm having some problems importing my sequences into the software. I Have my sequences in a FASTA ...
3
votes
2answers
689 views

Action potential changes in low sodium concentrations but constant osmotic pressure

If I bathe a squid axon in a fluid that has high sodium concentration , why does the duration of action potential decrease compared to a control experiment in low sodium bath but maintained at the ...
1
vote
1answer
754 views

Deciduous trees in tropical rainforest

Some books says the dominant plant form in tropical rainforest biome is broad leaved evergreen trees. Other books say it is broad leaved evergreen trees and deciduous trees. What is the most accepted ...
3
votes
2answers
140 views

Choosing appropriate statistical test for ordinal data

Ordinal response variables show up often in biology, but I'm not sure how they are best analysed. Some examples are qualitative assessments (little, many, a lot) or risk assessments (low risk, medium ...
9
votes
1answer
483 views

Mass spectrometry versus western blotting for validation

I have mass spectrometry data (LC-MS/MS) from rat cortices under either drug or control treatments. The results were performed in triplicate (three pairs of rats, drug or control per pair). In ...
3
votes
1answer
782 views

What is the purpose of segments in citrus fruit?

What is the purpose of segments in citrus fruit? In my experience, each segment usually contains from zero to two seeds. I may have seen more but only rarely, if I remember correctly. What is the ...
8
votes
3answers
272 views

Evolution: One big population vs. many small populations

Let's say I want to evolve a bacterium that is resistant to an antibiotic. I want to do this by growing initially clonal populations of bacteria in presence of this antibiotic for a long time. I have ...
2
votes
1answer
198 views

G>T transversion VS. T>G transversion?

So I'm reading about how mutations in DNA can be caused by oxidative damage. An example of a product of oxidative damage is given: 8-oxo-7-hydrodeoxyguanosine My textbook says that this product ...
7
votes
3answers
1k views

What is the science behind the inaccurate perception of colors?

If I go into a green room (all walls are semitransparent and green) and spend some time - around 10+ min - in there, when I come out all my eyes see is white as pink. I see no (or very few other) ...
11
votes
2answers
215 views

Is there any evolutionary advantage of selection of L-amino acid over D-amino acid?

After listening to a scientific talk, I had this question that why in the natural selection process, are the L-amino acids selected over the D- form. However, we still we produce D-amino acids; ...
3
votes
1answer
114 views

Specific location where nerves converge

I'm looking for the "earliest" specific site where the 3 following nerves' sensory signals "converge": Trigeminal nerve Median nerve Superficial peroneal nerve By "earliest", I really mean the ...
2
votes
0answers
60 views

Are the Chromosomes organized in any meaningful way? [closed]

So my major is in pharmacy but both my master and my (currently in progress) doctoral degree are both in theoretical chemistry. My thesis is about quantum chemistry and proteins, but it has a certain ...

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