6
votes
1answer
163 views

Regarding the kingdom Animalia, which phylogenic tree is more common: Molecular Comparisons or Body-Plan Grades

In the picture below, which I obviously do not own: it depicts two different phylogenic trees, one which is based on molecular comparisons and another one which is based on body-plan grades. My ...
6
votes
3answers
2k views

Why does replication require primers while transcription does not?

In transcription, there is no need for any primer. I guess the basic mechanism of DNA polymerase & RNA polymerase is the same. So why does replication have the need for a primer?
6
votes
1answer
213 views

What exactly makes bananas go brown?

I know that often oxidation processes are mentioned when referring to the color change from yellow to brown in bananas (specifically: those that you get everywhere in supermarkets, with no seeds). ...
6
votes
3answers
340 views

Are there genes in humans from the common ancestor of all organisms?

How long ago can human genes be traced? Are there any genes that go back unchanged to the beginning of life on Earth? And if so, how many?
6
votes
1answer
119 views

Macromolecule levels in daughter cells after fission

When a prokaryote undergoes binary fission, how are the non-DNA macromolecules distributed between the two daughter cells? This is motivated by comments on a previous question and a G+ discussion. I ...
6
votes
1answer
375 views

Human sleep cycles and dream times, what influences the timing and intensity? Sleep history included

I'm doing sleep and dreams research and have developed an iPhone application to help me track my bedtime, rise time, sleep onset and also mark dreams. The app also monitors overall activity overnight ...
5
votes
1answer
172 views

What is the name of this plant?

This plant was found growing in Germany. I have never seen it before, reverse Google image search did not help either. Can you help me identify what type of plant this is? Thanks, looks like it ...
5
votes
1answer
257 views

Getting goosebumps at will

I can get goosebumps at will, regardless of the environment. Its mostly visible on my arms, and I can feel it on my head. It requires some level of concentration to achieve this. My questions are : ...
5
votes
1answer
486 views

How to do western analysis to lung tissue?

I am working with lungs from mice, and I want to do a western blot analysis to my samples. I am having trouble with this because my images turn out very "messy", with a high background. Perhaps I ...
5
votes
1answer
140 views

Modern reference for Kropotkin's lazy bees

I have been reading through Peter Kropotkin's Mutual Aid: A Factor of Evolution and he mentions a curious fact about bees (bolding by me for emphasis): predatory instincts and laziness continue to ...
4
votes
2answers
139 views

What governs the size of animal bodies?

Million of years ago there lived dinosaurs up to 36 m high. About 10,000 years ago lived Machairodontinae -compared to cats today they were huge. About 400,000 years ago lived Mammuthus trogontherii: ...
4
votes
2answers
163 views

How is photosynthesis observed?

How is photosynthesis observed? Say I have plants A and B, and I want to find how fast they are able to turn carbon dioxide into oxygen. How would I experiment this? Say I have one plant A, which ...
4
votes
3answers
127 views

Book recommendations for evolutionary models

I was recently working on getting a statistical model of a DNA sequence. To do this I found that understanding evolution quantitatively seems to be quite important. I would really appreciate any book ...
4
votes
2answers
118 views

Can I force evolution in a group of cells by removing all the smaller cells?

I actually have algae growing in water in a container. I was thinking if it was possible to filter the water so that all the small cells will be filtered out and only the bigger ones will remain to ...
4
votes
1answer
151 views

Any examples of life forms on Earth that could have survived on Mars or Moon?

Do we know of any living forms on Earth that could continue to live on Mars?
4
votes
2answers
5k views

NaCl role in CTAB - DNA complex in DNA extraction

I have a question about the role of NaCl in the DNA extraction process. So for NaCl concentrations under 0.5M, CTAB and DNA molecules can create complexes. In those concentrations, proteins and other ...
4
votes
1answer
3k views

What are the advantages and disadvantages of being ambidextrous?

What are the advantages and disadvantages of being ambidextrous? We have two hands and we nearly can't use one and this seems like a weakness, and a stupid one when you first think about it. But ...
3
votes
4answers
1k views

Bad Eyesight and Evolution

Why do many humans have bad eyesight, such as near-sightedness, which hampers performance in a wide variety of tasks? Shouldn't there be evolutionary pressure towards better eyesight?
3
votes
3answers
3k views

Is the human body composition real?

In Fullmetal Alchemist when Ed goes to disprove to Rose the Sun God's "miracle" to bring humans back to life by proving that science (in the form of Alchemy) can create people by saying Water (35 ...
3
votes
1answer
161 views

Empirical evidence for Group Selection?

A controversial concept in Biology "Group Selection", has caused confusion and conflict amongst scientists since the since the mid 1990s. The more general realm of study is termed the "unit of ...
2
votes
1answer
138 views

What's the purpose of colorful mushrooms' caps?

What's the purpose for many mushrooms to have colorful caps? Is not it is in their interest to hide as well as possible? Or there are mushrooms that propagate by being eaten, like fruits? Why not all ...
2
votes
1answer
118 views

Does recombination increase the additive genetic variance for fitness?

On this article, first column, eighth line of the introduction: By bringing together favourable alleles from different chromosomes, sex and recombination increase the additive genetic variance for ...
1
vote
2answers
131 views

Which was the last significant event in human evolution? What's next?

At 10.000 BC (12 ka), we became the last of the Homo species on Earth. In evolutionary terms this is a very little time range to something happen, but I'm wondering anyway, in this meantime which are ...
1
vote
1answer
383 views

Does a fully-resolved phylogenetic tree have to be dichotomous?

I read that wherever there is polytomy there is an unresolved pattern of divergence. I don't understand why this is so. When divergence takes place, is it necessary that there will be division into ...
0
votes
2answers
1k views

Why have humans evolved conciousness?

Why did humans/animals evolve to become self-aware of their own thoughts. That is, why don't humans act and compute like a machine, or walking zombie. In my mind, such creatures would still be as ...
22
votes
2answers
10k views

What causes fingerprints to form and why is the pattern formed unique?

I've found research that suggests that the reason we develop fingerprints is because they aid us with feeling surfaces (Scheibert, et al. 2008) and not to increase friction and help with the gripping ...
18
votes
2answers
347 views

Can an adult without genetic lactase persistence still develop a tolerance for dairy foods?

While investigating the rise of adult lactose tolerance, I came across the news that China has been encouraging its citizens to drink more milk, even though most of the Asian population lacks the SNP ...
15
votes
4answers
2k views

Why would a single celled organism evolve to be multi-celled?

I read a story this week on Richard Lenski who has been 'evolving' E. coli for more than 50,000 generations now. One comment I read was from someone who doesn't accept Evolution who pointed out that ...
15
votes
2answers
1k views

Why do we get runny noses in the cold?

The most annoying thing for me about being cold is a runny nose. Is there an advantage to having a runny nose when cold? What does having a runny nose achieve?
14
votes
2answers
335 views

Is the human biological clock genetically programmed or learnt?

Argument favouring learning: A newborn sleeps for 20-22 hours. But overtime (s)he learns to focus sleeping time to night time, according to his or her needs and family needs. Some sleep from 1 am to 7 ...
14
votes
2answers
3k views

Will humans and animals be harmed by frequencies outside their hearing range?

The human ear (for example) is sensitive to frequencies from 20Hz to 20kHz. Any sound beyond that limit would not be heard by us naturally. Will it harm us (effect our ability to hear) when we hear ...
13
votes
1answer
4k views

Why can't humans drink sea water?

Why can't humans drink sea water? It would seem to be a huge evolutionary advantage for an animal to be able to drink sea water rather than have to rely on fresh water, and it's provably not ...
12
votes
3answers
2k views

What is happening when we get a tan?

Almost everyone nowadays wants that nice summer tan, but what exactly is going on beneath the skin? I've heard a few different theories about tanning - such as a tan is nothing but the pigmentation in ...
11
votes
3answers
349 views

Do humans perceive temperature or heat-flux? (or both?)

The general understanding is that when I touch an object, I perceive its (relative) temperature. A metal object at room temperature, however, will often feel cool to the touch. This leads me to ...
10
votes
3answers
160 views

Is there a fundamental reason that plants cannot fix their own nitrogen?

Plants must have nitrogen to grow. According to the answer to this question, there are no plants can fix their own nitrogen (without the help of bacteria). Plants get their nitrogen in the form of ...
10
votes
1answer
3k views

How to DIY preserve pet DNA today so that it can be used in 20 years

I know that there are companies that offer a kit+storage of your pet DNA for around $2k. My question is if there is any other option for doing this yourself with a thought in mind that in 20+ years ...
10
votes
1answer
623 views

How does laser surgery correct accommodation problems?

When someone undergoes laser surgery to improve eyesight, how does it correct accommodation problems? Why does it not help presbyopia?
9
votes
2answers
872 views

What are the differences between cancer and tumour?

What are the differences between cancer and tumour? I mean is it in the DNA or shape or something else... And how can a benign tumour turn into a malignant tumour? The body has a lot of tumours all ...
9
votes
2answers
2k views

What percent of your blood can you lose before you need a transfusion

Losing a little blood is okay. If your a normal healthy person, and got into an accident, how do they know if you need a transfusion or if you'll be okay? This is hypothetical.
9
votes
1answer
198 views

Seeing strange things in light

I have noticed that if you look directly at tubelight (I have only white ones in my home) and close your eyes little, you see little random shaped colourless things sometimes with slow speed and ...
9
votes
1answer
487 views

Does DNA react in all of the ways most other acids do?

As I understand it from my basic chemistry, there are some fundamental reactions that exist between any acid and other substances for example acid-base reactions that form a salt, and the existence of ...
9
votes
1answer
97 views

Which patterns do I have to avoid when modifying the 3'-UTR?

I want to change a pre-miRNA sequence (in my case the pre-miRNA is encoding in a 3'UTR of a gene) and then put it in a lentivirus to see if it is still processed. After modification (permutation of ...
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?
8
votes
2answers
202 views

How are antibodies designed?

Antibodies have the ability of recognising highly specific peptide sequences and bind it at their antigen-binding site. This ability is harnessed as a tool in research to purify target structures in ...
8
votes
2answers
711 views

Is it possible to live without health problems sleeping one day and not the other?

Basically, I want to know if it would be humanely possible to sleep one day, skip the next, sleep, skip, sleep, skip, etc, with a 8 hour sleep time. If you need any extra information, let me know.
7
votes
1answer
3k views

Why aren't organelles considered alive?

I'm taking a 3-week Bio I summer course, and my textbook says the cell is the smallest/basic unit of life. I asked my professor why organelles aren't a living unit, and her reply was that they aren't ...
7
votes
3answers
12k views

Why are 3 nucleotides used as codons for amino-acid mapping in DNA?

DNA is made of 4 unique nucleotides. When coding for a protein, a sequence of 3 nucleotides is used to code for each amino acid. Why are codons 3 nucleotides in length? A related question can be ...
6
votes
1answer
120 views

What is the scientific name of this evergreen plant?

This plant is found in India. It is an evergreen plant. Would love to know the scientific name.
6
votes
1answer
802 views

Why did humans lose their fur?

The little amount of body hair humans have don't seem to be of much use for keeping warm. Our Simian cousins on the other hand sport thick furs. At which point during the species evolution and why ...
6
votes
2answers
730 views

Alternatives to trypsin for cell detachment?

I have ran out of trypsin and need to passage my cells (immortalized chondrocytes, C28/I2) today or tomorrow. I have been out of town and forgot to order more trypsin. I was wondering if there are ...

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