5
votes
1answer
72 views

By what mechanism can hypoglycemia induce fainting?

Hypoglycemia (Low blood sugar) is said to be among the potential causes of human-faintings. I was wondering by which mechanism this happens. Google search results are abundant; there are lists of ...
0
votes
0answers
21 views

desaturation in fatty acids [duplicate]

humans are unable to synthesize EFA what is the reason behind it that humans cannot introduce double bond between C-10 and the methyl terminal?
1
vote
0answers
103 views

Slithering worm, snake or other? What did I just see? [closed]

I was working on some paving stones and underneath some of them I ran across red worms I see regularly. As I ran across them I would pick them up and fling them in other parts of the garden where they ...
3
votes
1answer
74 views

How much energy is required to blind someone?

As I understand the ravages of sunlight upon the (human) eye; the cause of ocular damage and blindness is too much energy delivered to the cones and rods that ultimately make up our eyes; so the ...
2
votes
1answer
49 views

MOL2 to PDBQT conversion via OpenBabel and MGLTools removes hydrogen atoms

I am trying to convert a MOL2 file (includes partial charges and hydrogen atoms) into a PDBQT file for re-scoring in AutoDock Vina. However, both approaches that I tried don't keep the hydrogen atoms ...
15
votes
1answer
3k views

Is humans' height ideal?

More or less we humans are around 1.70 meters tall. My question is, would it be possible to scale us? that is, is it in principle possible having humans 1 cm tall, or 10 meters tall or is there some ...
6
votes
1answer
34 views

Location of nucleotide synthesis and transport

I couldn't find this question directly asked so I thought I would ask it In Fundamentals of Biochemistry 3e (Voet et al), it has a small small little comment about pyrimidine synthesis: (In a diagram ...
3
votes
1answer
41 views

Horizontal gene transfer versus convergent evolution

There are several often noted examples of convergent evolution (eyes, bat/bird wing evolution etc.) How do we rule out horizontal gene transfer in these cases?
14
votes
4answers
2k views

Height and natural selection in humans?

I watched the documentary "Evolve" recently and in the segment on "size" Scott V. Edwards, Harvard evolutionary biologist mentioned the idea that humans might evolve to be 7' tall in 'hundreds of ...
3
votes
0answers
43 views

Intuitive explanation for Kin- and Group- selection

It is known from theoretician in the field of kin selection that kin selection (inclusive fitness theory) and group selection are actually two sides of the same coin. In other words, these two ...
4
votes
1answer
87 views

how many abdominal sclerites would be there in a cockroach

Every tegmina of a cockroach has Sclerites which are homologous to the bones of humans. Every abdominal segment of cockroach consists of two lateral sclerite plates called pleura along with a dorsal ...
1
vote
0answers
28 views

Has anyone used Crispr/Cas to induce a knock-in in MEF cells?

Does anyone have experience with the crispr/cas9 platform performed on MEF? Or does anyone recall any relevent articles? Thanks
2
votes
1answer
42 views

Can I identify this black ant queen?

I have an ant queen in a jar. This is what she looks like: Because I'm planning to start an artificial ant nest, I'd like to learn something about that specific species of ant. This particular ...
2
votes
1answer
44 views

To what extent do domestic animals understand language?

Note: Please tell me to re-post this in Cogsci or pets if this doesn't belong here. Hello All, I want to know how dogs or other domesticated animals differentiate between normal chat and a command. ...
5
votes
1answer
115 views

High frequency human genetic oscillators?

The most well studied genetic oscillators in human genomes are involved in regulating the circadian clock (which operates on an approximately 24-hour cycle) and cell cycle activity (with single cycles ...
3
votes
1answer
179 views

Identify this Harvestman

I spotted this guy in Switzerland. It's clearly an Opilione (Harvestman), but I really know nearly enough about this diverse group to be able to identify the species. Sorry, I didn't think to ...
7
votes
1answer
107 views

First RNA polymerase-mRNA

We know that RNA polymerase produces mRNA by reading DNA strand. Which enzyme produces the first RNA polymerase if other RNA polymerases are synthesized in the same way like other enzymes(proteins) ?
2
votes
1answer
51 views

tetrads in meiosis are held together by what

This is from SAT subject biology test practice question. The answer it gave me was both chiasmata and centromeres. I can understand they are held by chiasmata but why also centromeres? I looked it up, ...
3
votes
1answer
26 views

In chromatin, what are the differences among states, interactions, and structures?

I am new to the study of chromatin, and I am trying to understand what people mean when they write about chromatin states, chromatin interactions, and chromatin structures. What are the difference ...
8
votes
1answer
106 views

How should I feed and keep an ant queen?

I have captured wandering ant queen. I guess she was just fertilised and was looking for a place to start a hive. I'd like to create my own ant hive in artificial environment. I unfortunately only ...
5
votes
1answer
83 views

Lost Ability to Regenerate Body Parts during the Transition from Amphibians to Mammals

Why have higher-order animals lost the ability to regenerate body parts during evolution? Wouldn't it be better for survival? What is the evolutionary theory behind it?
2
votes
2answers
165 views

By what mechanism does elevated homocysteine level cause endothelial dysfunction and damage?

It has been stated that elevated homocysteine level causes endothelial dysfunction and damage. By what mechanism does this happen? Why is it the endothel where elevated homocysteine causes problems? ...
2
votes
1answer
51 views

Does adding milk to cereal make it harder for our body to absorb the vitamins and minerals from the cereal?

I add about 3/4 cups of Blue Diamond almond milk (unsweetened) every morning to a single serving of Cheerios. The milk contains filtered water, and I read that drinking water with food at the same ...
4
votes
1answer
33 views

Are there any strictly chloroplast/mitochondrion-residing ribozymes?

A simple question that had occurred to me. Considering the small doubt of transcribed genes in both organelles, I would doubt it, but are there any known ribozymes strictly found in either ...
1
vote
1answer
78 views

Question about the DNA glycosylase enzyme assay/formamide gel loading buffer

Often for the DNA glycosylase enzyme assay we can see that the DNA glycosylase is incubated with oligonucleotide in 37C and then reaction is stopped by addition of formamide gel loading buffer (80% ...
2
votes
0answers
39 views

Why Mammals are unable to produce Essential Fatty Acids?

While we have to get them from our diet and if they aren't taken in our diet we will face disease.Then why we don't have the enzymes which are require for EFA synthesis???
4
votes
1answer
69 views

Why might you NOT observe a tradeoff between two life-history traits?

I have traditionally thought of and heard about life-history traits (e.g., size at first reproduction, number of offspring, size of offspring, survival, etc., etc.) as drawing from a finite pool of ...
3
votes
0answers
11 views

How to make sure a stem cell culture is cancer free?

Say I take a blood sample from an adult, extract the white cells and apply to them the process described in <this article>. Assuming this actually turns the adult white cells into stem cells, which ...
12
votes
3answers
160 views

Why do some fruits have a much wider range of acceptable sizes than others?

Some fruits such as pumpkins can grow to be 100 lbs. Under different conditions, the same variety of pumpkin can produce a 15 lb. fruit. Both plants are healthy, and look the same except for their ...
10
votes
2answers
243 views

Have we ever observed two drosophila lineages that evolved reproductive isolation in labs?

Background The standard definition of species refers to the concept of reproductive isolation. If two lineages are found to be reproductively isolated, then we consider these two lineages to belong ...
0
votes
1answer
82 views

Schedules of mating for men

It’s simple deductive logic to follow that for a species to survive it must provide it’s offspring with the best possible conditions to ensure it’s survival – either that or to reproduce in such ...
0
votes
2answers
79 views

How can you explain the origin of life out of nonliving matter (abiogenesis)? [closed]

According to biochemist Robert Shapiro, the "primordial soup" theory is as follows: Early Earth had a chemically reducing atmosphere. This atmosphere, exposed to energy in various forms, produced ...
3
votes
2answers
245 views

Cranial Nerve Decussation

I want to get my head round this once and for all so if you guys could help me would really appreciate it! I understand lesions to the optic nerve. It is the other nerves that I find difficult. So ...
3
votes
3answers
94 views

More entropy: Atom or Macromolecule? [closed]

A question that appeared on my last exam was : Which of the following has greater entropy A) An atom B) A macromolecule The question doesn't specify anything else(i.e. type/size of atom or ...
7
votes
1answer
537 views

Does the human ear adapt to noise levels?

I have noticed lately that if I go to sleep, when I have my radio running, it is on lowest volume, I still consider it kind of loud. In the morning, when being on the edge of waking up, I hear the ...
4
votes
0answers
32 views

How does the frequency of a visual stimulus affect the steady-state visually evoked potential?

I want to make a project for EEG signal processing, and in my research I found the concept of SSVEP, which means that if you have a stimulus with low frequency applied to the eye, the electrical ...
6
votes
1answer
47 views

Absorption rate of Infrequently eating animals?

Clearly, creatures such as us humans, after vastly increasing the entropy of our food, expel most of the mass that we consume. Some creatures, however, do NOT get the opportunity to eat nearly as ...
2
votes
1answer
27 views

What is this black insect (wasp-like?) South America?

I live in the Pacific coast of South America. Seems to have two wings, like a wasp's. The "tail" is a bit bulky but is only connected to the rest of the body by a thin part. It's black overall. The ...
5
votes
1answer
83 views

Can NSAIDs impact negatively the healing of tendons?

There are a number of articles regarding NSAIDs having a negative effect on healing conditions like tendonosis and tendinitis. From what I understand the channel through which they reduce inflammation ...
8
votes
2answers
315 views

How do small animals make loud sounds?

Walking past the park today, I heard a cicada so loud I thought at first it must be some sort of large power tool. How is it that that very small animals like cicadas (crickets, etc.) can make such ...
1
vote
1answer
47 views

Source of hydrogen in reduction of oxygen in electron transport?

What's the source of hydrogen in the reduction of oxygen to water in metabolism? Is this implying that half the hydrogen comes from NADH and the other half from lone protons?
3
votes
2answers
1k views

Why do kefir grains stop growing in soy milk?

Kefir is a fermented milk drink made with kefir grains. It usually is prepared by inoculating cow, goat or sheep milk with kefir grains. I would like to prepare the drink with soy milk, which worked ...
1
vote
1answer
167 views

What is the recommended PPM when foliar feeding L-amino acids

It is said that L-amino acids such as histidine, methionine, aspartic acid, glutamic acid, asparagine and glutamine can revert plant stomata closure, increase quality of fruits and assist maturity. It ...
2
votes
3answers
163 views

Where are the evolutionary “inbetweeners”? [closed]

The problem I've always had with evolution is the actual lack of variation between animals. More specifically, the lack of observable gradual change between species. Take for example the hammerhead ...
17
votes
4answers
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 ...
11
votes
1answer
392 views

Supercomputer Vs Human Brain

With supercomputers doing calculation in petaflops ($10^{15}$ Calculations per Second), have we crossed the speed of Human Brain?
5
votes
1answer
36 views

Does fasting improves immunity?

I have heard that fasting causes regeneration of memory cells(B- and T-lymphocytes) thereby improving immunity.Is this true? If yes, how?
3
votes
1answer
47 views

How Behind is the Human Mind (Latency of the Senses)

I would like to know if there is any research into the latency of human perception. Particulary: What is the minimum time for various inputs (vision, touch, sound) to be recognized by the conscious ...
5
votes
2answers
252 views

Diffusion of Hypotonic solution into solution with glucose and starch

Cell walls are selectively permeable to ions and organic molecules. Sometimes the selectivity is passive and a reflection of the physical laws governing diffusion. We can do simple experiments that ...
5
votes
1answer
50 views

How can I tell if regulation is at the transcriptional or translational level?

I was reading a paper, http://www.pnas.org/content/109/8/E471.short, where the authors claim that (e475) Translation of the TfR (Transferrin Receptor) is regulated through sequences in the 3′ and ...

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