3
votes
1answer
109 views

Why is one testicle larger than the other?

Why is one testicle generally larger in humans? Just due to asymmetric development, or is there a hypothesis as to some utility it serves? I read that the different heights may be attributed to ...
3
votes
1answer
143 views

Why are cancer rates low in large animals?

Large animals generally have more cells and live longer than smaller animals. For example, bowhead whales live up to 200 years and weigh up to 100 tonnes, as opposed to humans (living ~71 years and ...
3
votes
2answers
331 views

How does ecology differ from biology?

What precisely is ecology? How does it differ from biology? Because I never studied biology after high school, please explain as if I were 10 years old. I only know that ecology is a subset of biology ...
3
votes
1answer
142 views

Any evolutionary explanation for human blood groups?

What is the explanation of people having blood types from an evolutionary perspective?
3
votes
1answer
215 views

Fecundity per woman in early humans

The average fecundity per woman varies a lot from country to country. I call average fecundity per woman the average number of born children per woman. In Homo sapiens, what was the average fecundity ...
3
votes
2answers
673 views

What does “chlorophyll photosynthesis peak” mean in relation to photon wavelength?

When reading about how green / leafy plants work, I saw that they have chlorophyll A & B, which allow the plant to use the energy from light by capturing and transforming. When reading about ...
3
votes
1answer
89 views

If two definitive ovums are fused will they form an organism?

Pretend that somehow in a laboratory two definitive ovums (finished 2nd miotic divisions) are are fused together. Will they form a new species?
3
votes
3answers
188 views

What are good sources of free-to-use images and diagrams

I am looking for good image repositories for biology teaching. Photos and textbook-like diagrams. I am interested in images that can be used commercially without payment, or, at least, that require ...
3
votes
1answer
68 views

What is the film that covers the tongue?

What is the film that covers the tongue in the mornings, even after brushing the teeth and tongue the night before and why does it have color variations? Do the different colors mean anything?
3
votes
1answer
316 views

Parasitism and mimicry

I was reading this article which states this: Classical Batesian mimicry, in which an undefended mimic evolves to look like a toxic model, is a parasitic relationship in which the mimic gains ...
3
votes
4answers
375 views

Why do the humans become sleepy after meals?

I don't know about all the mankind, but I know enough people, who becomes sleepy after their meals. Also, I'm not sure, what kind of food do they consume, but I personally get sleepy almost from any ...
3
votes
2answers
148 views

Humidity for wood rotting

If I put a piece of wood in a humid environment (basically humid air), it will start to rot. Does the humidity influence the rotting speed, and if so, what is the relation between the rotting speed ...
3
votes
1answer
387 views

Macroevolution vs. microevolution

Where is the line usually drawn between macroevolution and microevolution? I thought that, although similar processes govern both, the line was at the species level, with macroevolution being changes ...
3
votes
1answer
2k views

Circulation through the liver in light of drug metabolism

I have a lingering question which stems from an answer that I gave to What hydrolyses aspirin within the digestive tract and blood stream? When a drug or any other substance is absorbed into the ...
2
votes
1answer
155 views

Which of the two chromosomes in a pair is expressed?

I have completely dummy question. I have 23 pairs of chromosomes in the cells 23 single coming from my mother and 23 single from my father. So how my cell choose which chromosome, mother's or ...
2
votes
1answer
60 views

What dangers would the wireless transmission of power through microwaves pose to living organisms?

If we were one day able to harness the power of "wireless electricity", and INTEGRATE it into society, what disadvantages and/or dangers to living organisms would become relevant at that point? To my ...
2
votes
1answer
218 views

Why do some people burn and others tan?

Connected to What is happening when we get a tan? - Why do some people burn while other people tan? Very pale people tend to just burn while other people tan very nicely, what causes this difference? ...
2
votes
2answers
63 views

Database of medically validated SNPs

I'm looking for all possible sources of clinically tested human SNPs. There is a handful of databases that store SNPs (like dbSNP), but I only need those that have validated presence/absence of ...
2
votes
2answers
567 views

Using an analytical balance (0.0000 precision) to measure µg (micrograms)?

If i needed to prepare 200µg/ml of proteinase K, and the proteinase K was in a solid powder form, would I have to weight out 200 µg using an analytical balance, and if so, is it possible with a ...
2
votes
2answers
167 views

Local BLAST Copy Number per Hit

I generated a series of local BLAST databases using makeblastdb of metagenomic data and am searching for the presence of a particular gene. While I can do the normal BLAST analysis looking at ...
2
votes
1answer
376 views

Why are hard boiled eggs so homogeneous?

A eukaryotic animal cell is a complicated piece of biological machinery. Some major structures inside of the cell (see the image below) include: the nucleus, mitochondria, Golgi vesicles, and various ...
2
votes
1answer
67 views

Why do oncogenes show genetic dominance?

As we know that tumor suppressor gene causes cancer only when both the alleles are recessive in nature.But in case of oncogenes if only one allele is dominant it can cause cancer.Why in case of ...
2
votes
1answer
122 views

Has any creature ever devolved to be cold blooded? [closed]

Is this even possible? Because I have a non-scientific gut feeling that it is irreversible. Whales and dolphins are evolved from land mammals, and they've remained warm blooded while it doesn't give ...
2
votes
1answer
275 views

List of heritability estimates in humans?

Many people on this site ask questions that directly or indirectly have to do with heritability in human. Do you know a list of estimates of heritability of various traits in humans? Or could you try ...
2
votes
1answer
1k views

Is there any advantage of having a mitochondria for aerobic respiration?

If we consider the pathway of breakdown of glucose which includes glycolysis, the citric acid cycle and the electron transport chain, all these processes takes place in some prokaryotes and ...
2
votes
2answers
123 views

Do people with colorblindness have less cones or no cones of a certain type?

https://en.wikipedia.org/wiki/Color_blindness#Red.E2.80.93green_color_blindness Protanopia (1% of males): Lacking the long-wavelength sensitive retinal cones, Deuteranopia (1% of males): ...
2
votes
2answers
167 views

Agony, Hydrophobia and viruses in the light of evolutionary principles

I'm undergraduate physics student, but I've always been interested in biology. So I have a couple of questions about an application of the evolutionary principles to practice. Agony as the last ...
2
votes
1answer
144 views

Formation of ammonia from air and moisture

On extended bicycle trips I sometimes slept under a plastic sheet, which helped with mosquitoes on hot nights. But there was a noticeable build-up of ammonia which made this almost impossible for more ...
2
votes
3answers
7k views

Do cold blooded animals generate any heat?

In explaining energy and work to an 8 year-old I said that all conversion of energy generates heat as a by-product. For example, cars generate heat in their engines and running generates heat in our ...
1
vote
0answers
41 views

What further research can the result of gene variation detection be used for [closed]

We do a research on a particular cancer (for e.g. breast cancer). Now, we have a result for the gene variation detection (VCF file). What next steps do we need to do? We don't have a clear picture ...
1
vote
1answer
66 views

Why do heterozygous individuals have increased resistance to malaria?

I am aware that there is such a thing called heterozygous advantage, which is due to the presence of a certain single allele, and that an example of this could be with "sickle-cell anemia". I am ...
1
vote
1answer
221 views

How do DNA-binding proteins determine that they're binding to the correct DNA base pairs?

My professor posed this question to the class today - "How do DNA binding proteins specifically bind to base pairs?" He alluded to the different arrangements of hydrogen-bond donor and acceptors in ...
1
vote
2answers
696 views

Are eukaroytic promoters located in the 5' UTR region?

I was wondering if promoter sequences are located on 5'UTR region in eukaryotic organisms?
1
vote
1answer
43 views

Two mice heterozygote and black are reproduced. Find the probability of getting the filium dark and heterozygote [closed]

Well, here's what I did: P: Aa*Aa F1: 1/4 AA, 1/2 Aa, 1/4 aa, SO the answer is 1/2, but out teacher did this: AA(1) Aa(2) aa(1) and she said we divide the number of filium for the phenotypes ...
1
vote
1answer
211 views

Examples of how the presence or absence 2'-hydroxyl groups influence physicochemical properties of DNA and RNA

I know, for instance, that RNA is much more succetible to alkaline hydrolysis than DNA and this difference is determined by the presence of 2'-hydroxyl group in ribose. I have also heard that "DNA is ...
1
vote
4answers
568 views

How does HIV mutate into other strains while keeping their virulent phenotype?

How does a virus like HIV mutate into so many strains, and yet all of them are harmful to our immune system? What gives this virus the ability to mutate so efficiently?
1
vote
1answer
91 views

Why do eyes water in response to particular emotions?

It is common for people to experience very moving situations (sad movies, etc) and have a physical reaction to it (such as crying). I am curious about how emotions can physically lead to the act of ...
1
vote
1answer
45 views

Dehydration from caffeine, alcohol and other

Tea, Coffee, Beer, Coke etc… I wonder if the benefit from amount of fluid we get from them is bigger or smaller then the handicap of dehydration. In other words it is worth to drink them if we want ...
1
vote
2answers
106 views

human anti-mouse antibody

I have heard about human anti-mouse antibodies (HAMAs) and read that HAMAs neutralize murine antibodies, therefore decreasing the effectiveness of those murine antibodies. Is this true that HAMAs ...
1
vote
2answers
359 views

Why only female mammals have well developed mammary glands?

In course of evolution (possibly), mammary glands became vestigial in male mammals, but became fully developed in females. Is there any plausible explanation for this characteristic?
1
vote
1answer
220 views

Why do humans have irregular teeth and impacting wisdom teeth?

Imagine that horses, dogs, bears, and gorillas had teeth as unreliable as humans do, The interruption in behaviour and stress brought by teeth would cause them to be more prone to sinus infections, ...
1
vote
1answer
115 views

How non-invasive blood glucose concentration measurement work?

Diabetes patients need to conduct the “fingerstick” a few times a day. One of the mechanisms of "fingerstick" is to take small amount of blood sample and put it onto a test strip. The enzyme on the ...
1
vote
1answer
135 views

How is the rate of transcription influenced by temperature?

How is the rate of transcription influenced by temperature? More precisely, I am looking for an article who quantitatively measured the rate of transcription of an "average gene" and show how this ...
1
vote
2answers
2k views

What actually are the blood groups for human being?

We all know that, Human blood groups are of 4 types with Negative and Positive of each types. The Wikipedia article also states so. But according to this forum thread there are some other types too: ...
1
vote
1answer
223 views

Determining a patients biological age?

I am looking for an algorithm that shows the exact coefficients some variables that have on a hospital patient's chronological age versus their biological age. I understand a lot of the variables ...
1
vote
1answer
171 views

Pedigree Diagram help

I am asked to fill the genotypes in the spaces provided but looks like I am aving a little bit of trouble. can anyone help? thanks in advance!
1
vote
1answer
208 views

Artificial Propagation and it's relation to asexual reproduction

I know that asexual reproduction is also called vegetative reproduction. However I do not understand it's relation to artificial propagation. Is it a technique used for asexual reproduction (the ...
1
vote
1answer
2k views

Can food swallowed when a person is upside down reach the stomach?

If a person positions himself upside down and swallows food, will it reach the stomach against gravity? If so how?
1
vote
1answer
16k views

Can white eggs be considered as non-vegetarian? [closed]

I am basically a vegetarian and I find it very difficult to get an actual biological answer for this question on search engine. There are couple of links which discuss these argument but can not be ...
1
vote
1answer
936 views

What's the difference between life expectancy of cigarette smoker and general population?

Some say that smoking cigarettes will shorten lifespan. By how many years is the lifespan of a typical smoker shortened? What are the common cause(s) of death among smokers? Are there any known ...

15 30 50 per page