2
votes
1answer
83 views

How many different smells can a human recognize?

How many different smells can a human recognize? If the space of smells is not discrete, how many dimensions it has (for example, the space of colors is three-dimensional).
2
votes
2answers
314 views

How much of your stock solution should you take to make the 1000 cells/mL mixture? [closed]

You need a solution containing 1000 buccal cells/mL. You count that you have 125 buccal cells in 50uL, from a total solution of 8 mL. How much of your stock solution should you take to make the 1000 ...
0
votes
1answer
99 views

How does DNA mess up

When there is an error in copying DNA (a mutation), what exactly goes wrong? If G goes with C and A goes with T, I don't see how that part can mess up. Is the idea that when the double helix is ...
0
votes
1answer
85 views

Dimensional analysis Question

So I'm new to the dimensional analysis world and I'm little confused and the answers I'm getting are not convincing :( if the concentration of hemoglobin in a 5ml sample of blood is 34 g/dL. and red ...
4
votes
2answers
338 views

What is the proper quick freezing /snap freezing protocol for pancreatic tissue?

I would like to do a quick freeze on pancreas from mice. I want to then make sections (30 µm thick). The idea is to preserve a fluorescent staining done in vivo. I do not know if I should place my ...
-2
votes
1answer
49 views

Which chemical and hormonal effects on heart are by metabolites? [closed]

I am thinking which hormonal and chemical effects from: catecholamines thyroxin corticosteroids sex hormones prostaglandins Ca2+ Na+ K+ can be be regarded as metabolites i.e. intermediates or ...
1
vote
1answer
31 views

Which inflammatory response with Cytomegalovirus infection?

I am thinking about inflammation process with Cytomegalovirus infection. I first thought it is about chronic inflammation, but then changed my mind because of virus infection. I think cytokines must ...
1
vote
1answer
18 views

2 types of telomerases?

As telomerase works by adding new nucleotides complementary to the RNA it contains, it cannot work for the complementary strand. Say telomerase X has RNA complementary to the 5' to 3' strand it ...
3
votes
1answer
47 views

What stops telomerase?

The telomerase is an enzyme that adds telomeres. What stops the telomerase from adding too many telomere sequences ? What's the regulating mechanism ?
1
vote
1answer
87 views

Why are low throughput methods more trustable for protein interaction?

I read that protein interactions found using high throughput methods are less trustable than those found using low throughput methods. For example, searching for interaction of BRCA2 on BioGRID, I ...
2
votes
1answer
42 views

Meaning of the word Oleracea

What does "oleracea", as appears in numerous plant species (scientific) names, mean? Examples: Euterpa oleracea, Brassica oleracea, Portulaca oleracea, Acmella oleracea, Spilanthes oleracea.
1
vote
2answers
107 views

Conserved proteins are non immunogenic

I read that proteins that have been highly conserved are non-immunogenic. Why is it so ? What is the special thing that makes it non immunogenic(antibodies against them are hard to make) ?
1
vote
1answer
136 views

Does the lung absorb organic food?

Imagine you swallow something up and not everything gets out of the windpipe (this is possible right?). Would it be possible for the lung to handle with the rest implying that it is organic? Would it ...
4
votes
2answers
768 views

If DNA has a half life of about 500 years, how can old seeds be planted?

According to this article, DNA has a half life of 512 years Wikipedia claims that there are seeds planted as old as 31000 years Doing the basic math $100 / (2^{30000/512})$ we get that only about ...
15
votes
2answers
2k views

Is there an advantage to linear chromosomes?

The DNA copying enzymes have a hard time working to the end of a chromosome. For circular chromosomes this is not a problem, since there is not a sharp 'end'. However, for a linear chromosome, without ...
6
votes
1answer
583 views

How much does the distance between a transcription factor binding site and a promoter influence transcription?

Assume we have a synthetic construct with a minimal (inducible) promoter that requires activation for significant transcription to occur. Realistically, how important is the distance between an ...
2
votes
1answer
65 views

Effective population size when the population sizes varies from season to season

Let's think of a species which has four generations per year and which population size changes from season to season so that the population size is 100 in summer, 200 in spring, 50 in autumn and 20 in ...
4
votes
1answer
745 views

Examples of animals with different number of chromosomes that can interbreed?

When I was first started to write this question, I wanted to know how species evolve to have a different chromosomal arrangement, such as having two pairs of chromosomes instead of one? However, I ...
2
votes
0answers
59 views

College Bio Research: Bacteria found on computer keyboards. [closed]

I am a college students brainstorming ideas on different topics that may be appropriate for on-campus research. What I came up with and I would like to give it a try is analyze the different types of ...
1
vote
1answer
241 views

circularizing DNA molecules?

I have been reading about next-generation sequencing technologies that can sequence long reads. Even though the origin of my question is sequencing technologies, the question I am asking is about the ...
2
votes
1answer
63 views

Would expression of GroEL and GroES in erythrocytes be a potentially effective therapy for sickle cell disease?

Would expression of GroEL and GroES in erythrocytes be a potentially effective therapeutic strategy for sickle cell disease? Why or why not?
2
votes
1answer
134 views

Evolution of Homo Erectus to Homo Sapiens

I just read an article on Wikipedia and noticed that some similarities between Homo Erectus and Homo Sapiens in the "Comparative table of Homo species". My question is; Is it possible to say that ...
1
vote
1answer
54 views

Omics integration questions [closed]

Let's say that I have a population of Mus musculus in the lab. I divide it in a control group and a test group. The test group is constantly subjected to a stress (example: elevated UV radiation). ...
1
vote
1answer
74 views

Why are new vessels more permeable in microvasculature?

I know for microvasculature New microvasculature (arterioles, venules) are always more permeable as they lack pericytes. and then I have this sentence about new blood vessels (not specific) ...
2
votes
1answer
356 views

What kind of a microscope do I need to see cell organelles?

I would like to study cells and looking for a microscope that would allow me to see: groups of cells individual cell cells organelles I would like to target insects and mammal tissue. I would be ...
2
votes
1answer
67 views

How much solar energy required to compensate food?

Just curious, how much solar energy can power an (herbivore) animal? Specifically, is it enough sunlight on Mercury (4 to 10 times brighter than on Earth) to "feed" a zebra? Will it be sufficient at ...
1
vote
1answer
59 views

Is it easier to burn a calorie of fat or a calorie of a carbohydrate?

Say someone eats 100 calories of chocolate vs. 100 calories of carrots. Something tells me that eating the chocolate will lead to you generating more fat. Will it? Is it harder to burn the calories ...
4
votes
2answers
170 views

What is the evolutionary purpose of the topology of the human ear?

What is the evolutionary purpose of the topology of human ears? I understand why the ears may have a funnel-like shape but if the various "hills and valleys" do not amplify incoming sound, what ...
1
vote
1answer
143 views

Real time PCR parameter CT

When puting a real time PCR, parameter CT, which means threshold cycle, is used. What does it mean really? according to wikipedia "The number of cycles at which the fluorescence exceeds the threshold ...
0
votes
1answer
21 views

Do animals follow tactics?

Are animals able to plan hunts, give tasks if they do it in groups and fulfil it adapted to the current situation? Do they use unique tactics for special circumstances (e.g. based on experiences) or ...
1
vote
1answer
36 views

Drosophila Crosses

I have 2 transgenic lines of Drosophila. I would like to cross them and get both transgene in the same fly. To start this cross, does it matter which fly is female or male? Or as long as the female is ...
1
vote
1answer
132 views

Is Natural Selection like a Copy Editor?

I am stuck on a Homework Question. It says: Evaluate the following statement: “Natural selection works like a copy editor; it works only with what is already present in a population.” (Note: ...
9
votes
1answer
380 views

When does weak selection produce qualitatively different results from strong selection?

In evolutionary game theory, it is typical to model organisms as having a base fitness that is modified slightly by the game interaction. The ratio of the game effect versus the base fitness ...
0
votes
1answer
56 views

Resources for interesting facts about biology [closed]

Are there resources for interesting or fun facts about biology, for example: fastest animal/bird/insect largest organ in human body largest virus largest genome largest de novo synthesized genome ...
2
votes
0answers
53 views

Lethality of a stab wound to the back

How deadly is a stab in the back? Video games, movies, and other fiction would have us believe that a backstab against a foe with a modestly-sized blade leads to immediate and certain death, having a ...
4
votes
2answers
173 views

Evolution in fruits

So, I saw a video on YouTube that says the banana we eat today is not what a banana looked like years ago. Since the banana has been genetically modified over the years, does that qualify as ...
-1
votes
1answer
69 views

Organs lifespan out of the body [closed]

What organ can be conserved outside of the body for the longest time and still function when reimplanted?
0
votes
1answer
27 views

What are these white areas of coronary thrombosis?

Please, see the picture where the areas (1,2,3) look little yellow: I think these areas are fat, platelets and/or air. I think 3 is fat/platelets while 1 is air/platelets. There also exists white ...
1
vote
2answers
82 views

Why only water in liquid form is essential to live?

My question is:- Only liquid water supports almost every living organism's metabolism, neither the vapour nor the condensed form of water does so. What is the chemical & the biological reason ...
4
votes
1answer
243 views

What is the minimum length required for a circular DNA ligation?

What is the minimum length of a DNA molecule for the ends to come in close enough contact that they can ligate. Assume there are free divalent cations in solution. Does anyone have any idea?
3
votes
2answers
179 views

Why ducklings are yellow?

Why ducklings are yellow, what the evolutionary background for this? How could it help to survive? UPDATE I agree with comment below, I did remember then that ducks are wild animals too (when I ...
6
votes
2answers
1k views

How would constantly growing nails have aided early human?

Nails grow rapidly and constantly, such that without constant artificial trimming they would reach lengths difficult to manage. How did this benefit early humans, say 200kya? Were they used like ...
4
votes
1answer
118 views

Identify this spider

I found this spider on my balcony in Sunnyvale, CA. It sat in a irregular net. The body was approx. 6mm long. Which species does it belong to?
2
votes
4answers
69 views

What evidence do we have to derive a rate of evolution?

When analyzing how the human species evolved and will continue to evolve over time, what evidence and tools (theory/models) do we have available to derive the rate at which this happens? Is it even ...
8
votes
2answers
2k views

Why do I need a flu shot every year, while many other vaccinations last years or even a lifetime?

Is it a viral vs. bacterial thing? Is there just more variety among types of flu than other diseases, so that this year's vaccines don't cover next year's flu?
0
votes
2answers
41 views

Does fat on our heart come from the fat that we eat?

If we eat fat: Does the fat go into heart, arteries and fat cells. OR Is the fat digested, following which our body creates fat that goes into heart, arteries and fat cells. Which one is right?
8
votes
2answers
307 views

How does a veggie-less diet affect the human body?

I have some question, which I'm sure would fit better in the fitness section but proper answers should probably come from someone that knows biology. My question is rather simple. How can a person ...
6
votes
3answers
101 views

laboratory mice, nutrition, and humans

It seems that many nutrition experiments [directed at human diet] are carried on laboratory mice. Is there any justification that nutrition that is good or bad for laboratory mice will also be same ...
3
votes
1answer
292 views

From a purely biological perspective, how does an optimal human diet look? [closed]

There is hardly any subject as contested in the media as what humans should eat. Usually, such discussions are devoid of actual scientific reasoning, though they all claim to be backed by scientific ...
4
votes
1answer
187 views

How do wild animals get rabies?

I can see the chain of spreading disease: Humans usually get rabies from domestic animals, those usually get it from wild animals, wild animals in their turn get from the other wild animals and here ...

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