All Questions

0
votes
1answer
27 views

What impacts penetrance of Huntington's disease?

From Principles of Life by H. Craig Heller, David E. Sadava, Mary V. Price: From what I understand, Huntington's disease exhibits varying degrees of penetrance depending on how many times the ...
0
votes
0answers
12 views

Which organism like to eat fat and oil? [on hold]

Fat and oil is high energy nutrient. But not so much organism utilize it as energy source. So I want to know what organism ;other than human, some carnivore that eat fatty meat; like to eat fat and ...
0
votes
1answer
8 views

Ways to measure effectiveness of a gene therapy trial?

I understand that Fluorescence in situ hybridisation can be used to measure the effectiveness of a gene therapy experiment/trial. But what are some other genetics techniques to measure the ...
0
votes
1answer
27 views

Which (naturally selected) evolutionary process led to the development of egg-laying?

I understand that eggs were around before chickens, and therefore this age-old question isn't properly framed. But the idea still stands, there was a first egg-laying organism which modern chickens ...
-1
votes
1answer
8 views

Cells “grown in LB broth to an OD600nm” [on hold]

Cells "grown in LB broth to an OD600nm" What does the OD stand for in this?
3
votes
0answers
32 views

Does eating antacid (such as Magnesia) before meal have any impact on digestion?

During an anatomy lecture I heard of the importance of the acidity of gastric acid (e.g., killing microorganisms, dissolving food, being a factor for triggering further processes). If a healthy person ...
4
votes
3answers
63 views
+50

Why do I feel funny in my tummy when riding a virtual roller coaster?

I've ridden a virtual roller coaster on an Oculus Rift. I felt tension as I went up to the top, but more interestingly I actually felt my stomach drop when I went down the steep drop on the other ...
0
votes
1answer
36 views

What is the progressive evolutionary advantage that leads to flying?

As far as I understand, all life started as non-flying and flying came about by natural selection. What is the evolutionary advantageous "path" to flying? Or is there something else to explain this?
6
votes
4answers
488 views

If Evolution Is In Progress, Why Fight Extinction?

Natural selection is a central tenet of evolution. However, most biologists seem determined to prevent the extinction of the species that have been selected against. Why is this? Preservation of ...
2
votes
1answer
32 views

What is the difference between a phosphotransferase, a phosphatase, a phosphorylase and a kinase?

I've looked in several sources, but I'm still confused. This is what I have so far: A phosphotransferase catalyzes the addition of a phosphate group. A kinase is a type of phosphotransferase that ...
3
votes
1answer
20 views

Why is Cysteine and Tyrosine used to calculate a sequence isoelectric point?

Why are the amino acids - cysteine and tyrosine used in isoelectric point calculations for a protein sequence, yet neither of them are positively charged molecules? and are not used in net charge ...
0
votes
1answer
18 views

Is this a valid definition of independent assortment?

"Allelic combinations separate randomly. I.e. a parent might be Aa and Bb for two traits but that doesn't necessarily mean the gametes will strictly be AB or ab but any of a number of combinations. ...
3
votes
1answer
58 views

XXY (Klinefelter's) & Trisomy 21 & X-inactivation

I read that X-inactivation doesn't tend to happen in males, but then when someone is XXY, they are a male because of the Y. However these individuals tend to live. So does that mean that ...
0
votes
1answer
30 views

What are non-heritable changes to genomes?

I am told that mutations are heritable changes to the genome. So this begs the question - what are non-heritable changes to genome?
0
votes
1answer
26 views

What are the structual differences between DNA and RNA? [on hold]

How is the structure of DNA different from that of RNA?
2
votes
2answers
62 views

Book recommended for neurobiology

I am looking for a good explanatory book concerning Neurobiology. I am interested on how the brain works but prior to this I believe that I have to start learning things about the biology of neurons. ...
1
vote
0answers
10 views

Gene Therapy for Cystic Fibrosis Extension

Thank you everyone for answering my previous two questions on CF. I have decided to write a paper specifically on the use of viral vectors and gene therapy for cystic fibrosis. I was told by my ...
1
vote
0answers
19 views

C. elegans and nutrition

If there is ample amount of food, do C. elegans worms know when to stop eating or do they store extra energy? Could they put this extra energy to use by moving faster or putting more eggs?
3
votes
1answer
66 views

Mechanism of Muscle Growth

According to this video (sorry for the poor reference but it represents my level of understanding in physiology), muscle grow as a consequence of repairing micro-lesions. How are these micro-lesions ...
6
votes
1answer
91 views

How fast can a human run?

I'm a runner (cross country) and I'm always amazed at how fast Olympic sprinters are. There's a lot of hype about those in the 100-meter dash being the fastest in the world, and we're constantly ...
4
votes
2answers
133 views

The gender of offspring of Twins?

Given identical twin males, Michael and Douglas, Douglas and his wife have four children, all of whom are girls. Michael and his wife have only one child, a boy, and are expecting another. What are ...
4
votes
1answer
241 views

Why do antidepressants have a delayed onset of action?

Why do antidepressants take so long to reach efficacy? I've read of theories about it perhaps being due to the strength of negative feedback via serotonergic and adrenergic autoreceptors during the ...
0
votes
0answers
15 views

Cropping with VMD [on hold]

I was wondering if it possible in VMD to render an image and set render commands that will produce a picture, where the white space around my figure is minimized. What I basically want is a rendered ...
0
votes
2answers
84 views

Does “Garbage Enzyme cleaner” contain cleaning enzymes?

There are many recipes which call for using fruit peel fermentation process to make a concentrated enzyme cleaner solution, some variations call to add bakers yeast. So the question arises that does ...
0
votes
1answer
25 views

Does too much Genetical Modification leads to formation of new species?

I think Genetical Modification can be termed as 'Artificial Mutation'. Is it possible that genes can be modified so much that it leads to the introduction of new Species i.e Can integration of large ...
4
votes
1answer
38 views

Mechanisms of extracellular stimulation of neurons

When stimulating a group of neurons with an electrode, let's say we put it in a region that contains axons, what is the mechanism by which the axons are stimulated? I've been told electrodes ...
14
votes
1answer
505 views

Why is the Krebs cycle considered a part of aerobic metabolism if molecular oxygen is not involved in any of the reactions in the cycle

Why is the Krebs cycle considered a part of aerobic metabolism if molecular oxygen is not involved in any of the reactions in the cycle? I originally thought that Krebs cycle was aerobic metabolism ...
0
votes
1answer
21 views

Could transfusion of a different blood type cure blood-based cancers?

Different antigen detection triggers an immune system response that could perhaps stimulate mitochondria and such in killing cancer cells - something like chemo without the hair-loss?
1
vote
0answers
12 views

what is the role of ctab in plant dna extraction [duplicate]

i get good results for dna extraction by using ctab method but i doesn't have that proper information for role/function of ctab and other chemical. Anyone know, please briefly explain ......
2
votes
1answer
46 views

Poisonous plants, animals, mushrooms: is this always a kind of defense?

I wonder whether developing deadly toxins in the organism's body is always or usually a defensive strategy rather than a by-product.
21
votes
5answers
2k views

Why are there species instead of a continuum of various animals?

As I understand it, various animal traits have to evolve gradually, but what happens to the species that are "neither here nor there"? To put it differently, if a species evolved from another, it did ...
2
votes
1answer
33 views

What can myelination tell you about the evolution of sensory receptors?

I am reading Avi Chaudhuri's Fundamentals of Sensory Perception and wondering if the information given about the somatosensory system could tell us anything about the way it evolved. It seems (at ...
10
votes
1answer
134 views

How reversible is DAT upregulation from long-term ADHD medication use?

A mechanism for ADHD stimulant medication tolerance has now been found. See http://neurosciencenews.com/adhd-medication-patient-brains-adapt-dat/. Here's the thing though: what exactly is the ...
0
votes
0answers
25 views

Are Humans Evolving? [duplicate]

Due to migration & absence of reproductive isolation,has human evolution stopped? As evolution occurs when there is absence of mating between two population,growing trends of interracial ...
5
votes
2answers
65 views

Functions of the CFTR gene?

I am a senior in high school and I am studying cystic fibrosis. I don't quite get the function of the CFTR gene as this is my first time dealing with this type of heavy scientific info. I had ...
2
votes
2answers
62 views

Why is Eadie- Hofstee Plot not linear

Besides the reason of cooperativity between multiple active sites on an enzyme, what are the other reasons for the Eadie-Hofstee plot to be non-linear
0
votes
0answers
52 views

How can periodic asystole of heart cause cataplaxy with partial asystolic syncope? [on hold]

In brain, it can be called reflex asystolic syncope - symptom unconsciousness. In heart, there can be temperary asystole, still with consciousness. If these occur at the same time but with brain ...
5
votes
1answer
83 views

What is the H+ gradient in mitochondria?

I would like to understand what the term H+ Gradient means. I googled this question and found terms such as chemiosmosis and ion gradient being tossed around. I am very new to biology and I do not ...
0
votes
0answers
27 views

Gene Therapy for Cystic Fibrosis

I have another question regarding cystic fibrosis. I understand that gene therapy is currently being talked about in the cure for cystic fibrosis. I know that Eric Alton at imperial college London is ...
2
votes
1answer
89 views

Do SSRIs downregulate or upregulate the 5-HT3 receptor?

What effect do SSRIs have on the expression of the ligand-gated ion channel, the 5-HT3 receptor?
0
votes
0answers
17 views

What accounts for diversity in species? [duplicate]

Why are there so many similar life units? (creatures, plants, etc.) Or, in other words, why is there great diversity among life units yet great similarity between similar groupings of life units? Why ...
0
votes
0answers
24 views

What circumstances allowed humanity to flourish (Where did ALL the humans come from?) [on hold]

Based upon some responses to What should three men and three women do if everyone else is dead it got me thinking, "Certainly something of the sort had to happen to humans, or, generally, any given ...
5
votes
1answer
55 views

Are fish and reptilian scales homologous?

Wikipedia: Fish scales are dermally derived, specifically in the mesoderm. This fact distinguishes them from reptile scales paleontologically. So aren't reptilia scales also dermally derived?
0
votes
0answers
25 views

i need help on a chart comparing mitosis and meiosis [on hold]

I inserted the chart I did the first two blanks but the rest really confuses me and this is due real soon I need help. I have to chose from the answer options.
1
vote
1answer
38 views

Bacterial Cell Problem

A microbiologist has discovered what she thinks are two new types of algae. The first cell (Organism 1) appears cubic and is approximately 1.5 μm long, 1.5 μm wide and 1.5 μm deep. The second ...
2
votes
1answer
70 views

For how long can a raven stay airborne (a week or more)?

I'm wondering for how long a raven can stay continuously airborne, if strained to do so? If it makes a difference, I'm mostly interested in the Common raven, Corvus corax. Are there for instance any ...
8
votes
3answers
131 views

Which part of the brain needs to be shut down to lose conciousness?

Whether it is mechanical (trauma), chemical (anaesthesia) or electrical - which part of the brain is shut down to cause loss of consciousness?
9
votes
3answers
654 views

How are our senses dimmed during sleep?

Our senses are not as sensitive during sleep compared to wake. There is an arousal threshold during sleep that only when it is overcome will it wake a person up. My question is how is this arousal ...
2
votes
0answers
29 views

What is the allelic frequency at mutation-selection-drift equilibrium?

mutation-selection equilibrium At mutation-selection equilibrium the expected frequency $f$ of a given locus is $$f ≈ \frac{\mu}{s\cdot h}$$ , where $\mu$ is the mutation rate, $s$ is the selection ...
1
vote
2answers
54 views

Why would yeast grow but not produce alcohol?

I'm studying for my intro to microbiology test and I have a question asking why a culture of yeast responsible for producing alcohol would be growing, but not producing alcohol? The multiple choice ...

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