1
vote
1answer
56 views

About the apoptosis mechanisms in a cell

The apoptosis mechanisms in a cell are like a type of 'self-destruction mechanism': is this correct? As with any type of complex system with various necessary functions, if it has a set of ...
6
votes
1answer
174 views

The origin of molecular machines

DNA holds genetic information and holds the key to the evolution of living organisms. Transcription and translation mechanisms enable living cells to process information encoded in DNA. To that end, ...
8
votes
2answers
253 views

Why don't we see turbulence in the aorta even in normal situations?

I read about the Windkessel effect. Then I read about pulse pressure waves getting reflected from the periphery. If the pulse pressure wave is reflected during diastole and at the same time blood is ...
3
votes
3answers
818 views

If ants have an antibiotic gland, how can they spread hospital infections?

Wikipedia describes how antibiotics are produced in ants: "Metapleural glands ... are responsible for the production of an antibiotic fluid that then collects in a reservoir ... also referred ...
1
vote
1answer
126 views

What's the meaning of 'plasma' in 'plasma membrane'?

I wonder why is it called plasma membrane - what's the biological meaning of the word 'plasma'?
0
votes
0answers
75 views

I brought a hibernating yellow jacket queen into my house accidentally. What will happen?

There was apparently a hibernating yellow jacket queen in my stack of firewood outside. An hour or so after bringing in the firewood, we saw the queen fly off into the house, where we can't find her. ...
1
vote
1answer
436 views

How does salinity affect the bonds of an enzyme?

According to my textbook, "Too much or too little salt can interfere with the hydrogen bonds that hold an enzyme in its three-dimensional shape". I know that NaCl is held together by an ionic bond, ...
2
votes
1answer
100 views

How do catalase and other antioxidants neutralize free radicals?

In learning about how cofactors are essential to proper enzyme function, my textbook mentioned catalase and its relation to the human body. According to my textbook, catalase is similar to hemoglobin ...
9
votes
1answer
4k views

What's the smallest size a human eye can see?

During a biology experiment at school, where we would look at waterweeds under a microscope, my teacher said something about that it's impossible for the human eye to see the cells without a ...
6
votes
1answer
170 views

When did our ancestors switch to a menstrual cycle instead of the estrous cycle?

The Wikipedia page on the Estrous cycle says: Humans have menstrual cycles instead of estrous cycles. They shed their endometrium instead of reabsorbing it. Unlike animals with estrous cycles, ...
2
votes
0answers
37 views

How much difference in genome is enough to prevent interbreeding? [closed]

I am not a biologist. I am a software developer interested in genetic algorithms therefore i am probably talking to biologists who also have a knowledge of genetic algorithms. I need to "breed" ...
2
votes
2answers
58 views

Are we more/less resistant to infectious diseases during an allergic reaction?

To my understanding, an allergic response is a non-adaptive response of the immune system to some molecule. The molecule in question is therefore "thought by the immune system" to be infectious ...
3
votes
2answers
93 views

Need help in codon optimization

I want to chemically synthesize a GFP gene for expressing in rice.I am using the IDT Codon Optimization program and found that not all the codons are 100% optimized. Some of them are the 2nd or 3rd in ...
5
votes
1answer
97 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
138 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
54 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
95 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
94 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
273 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
380 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
839 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
346 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
98 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
223 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
135 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
603 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
371 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
152 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
107 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 ...

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