3
votes
1answer
90 views

Why do hummingbirds build nests with live ferns instead of dead materials?

Hummingbirds prefer to build their nests with spore-bearing ferns, and mosses. This is helpful for the reproduction of the ferns, which are then better able to spread their seeds. But how is this ...
1
vote
1answer
122 views

Calculating photosynthetic efficiency

While calculating photosynthetic efficiency, do we take into account the Gross Primary Production or the Net Primary Production ?
4
votes
0answers
176 views

How do duplicate brain regions (ex: left/right amygdaloid body) operate together?

I frequently hear talk about parts of the brain like "Amygdala" or "Hypothalamus", so I looked them up in an app called "essential anatomy". What I see is that there's mirror symmetry, and most of ...
1
vote
1answer
123 views

Is end-systolic volume (ESV) the same as residual volume?

I am reading this site and my study materials. The end-systolic volume (ESV), 50-60 ml, is the volume of blood found in ventricles after systole and contraction of ventricles. I think ESV is the same ...
3
votes
3answers
89 views

Can 'hardware' thermalization explain memory decay?

Often we are able to memorize very precise bits of information (exact addresses, birthdays of inlaws, number of dirty socks under the bed), but over time our recollection tends to become fuzzy. We no ...
6
votes
2answers
132 views

What type of force holds my body rigid & doesn't make it collapse?

My query is that as atoms & its molecules have inter & intra molecular forces,like that only what type of force keeps the cells bonded to each other & prevent it from collapsing ever ...
4
votes
2answers
197 views

Can diploidy evolve in absence of sexual reproduction?

Theoretical question Can diploidy (or polyploidy) evolve from a haploid lineage in the absence of sexual reproduction ? For what theoretical reason? How can such evolution take place? Empirical ...
-1
votes
1answer
89 views

Can nature create codes and specified complexity? [closed]

Is there an example of nature creating codes or specified complexity? It is said by Creationists that codes can only come from minds, and since DNA has a code, it was created by a mind. Is this true? ...
0
votes
1answer
49 views

An over-simplified model of cell division and its relation to stem cells

I am a mathematician, and I decided to try to model cell division with math and see what conclusions came out of it. I had some questions concerning stem cells that came up in the model. In an ...
1
vote
1answer
57 views

RNA integrity and RNA fragmentation

After RNA isolation and before following experiments, I know that RNA quality so called RNA integrity is so important. So why there is a RNA fragmentation kit? Do we need RNA intact or fragmented? ...
1
vote
1answer
80 views

Dilution question about RNA

I have a basic and probably silly question. I am isolating RNA with TRIzol. I have performed the basic steps and dissolved the pellet in 50 uL water. I ve measured the concentration and it was 3313 ...
0
votes
2answers
485 views

Can you answer Ray Comfort's question on Biological Evolution? [closed]

https://www.youtube.com/watch?v=U0u3-2CGOMQ There's this video on Youtube about biological Evolution that has gone viral. I'll paste it above for your convenience. To cut to the chase, Ray Comfort ...
0
votes
1answer
56 views

Normal position of Electrical axis only in the III lead?

I found this sentence in my notes which is not exact enough: Electrical axes Excitatory processes have definite direction and magnitude and could therefore be represented as vectors. At ...
6
votes
2answers
633 views

Why aren't we ambidextrous?

It seems so simple that if my brain can tell my right hand to do something, then it should be able to tell equally well to the left ? This seems like a pretty major evolutionary advantage. Why haven't ...
0
votes
1answer
94 views

How does a smoker's pleasure work?

I smoke. For some reason, I've always had this idea that the pleasure of smoking works more or less like this: from the lungs, the nicotine reaches the blood, with which it travels to the brain, and ...
1
vote
1answer
79 views

Physiology of skin and leather: why do salt borders occur?

I discussed a leather store about the white border aka salt border on leather shoes. They said that it is due to inner features of leather and you could try to add some fat/cream to push it back ...
-1
votes
1answer
75 views

Can a certain part of human dna can be replaced with other animals dna?

Human DNA consists of adenine, thymine, guanine and cytosine. Can thymine of other animal can be placed with humans thymine?
0
votes
1answer
73 views

Difficulty in developing certain vaccines

I have a college level background in Biology, say at the level of Campbell. I am very curious to know why it's extremely difficult to develop vaccines for certain diseases. Two cases which I am really ...
16
votes
3answers
2k views

Are humans the only animal that requires “clean water”?

I've seen a number of animals - dogs, cats, squirrels, ducks and geese, etc drink from puddles, some of them were muddy, others had green flora growing under water. Same goes for lakes and rivers. A ...
1
vote
2answers
63 views

Referencing the homologous chromosomes

There exist a co-ordinate system from chromosomes like "12p11.3". In this system, first integer range from 1 to 23 i.e it takes homologous chromosomes as a pair. If we want to distinguish among ...
4
votes
1answer
132 views

What constitutes the determination of a normal blood glucose level?

Several on-line resources (e.g. MedlinePlus) suggest: Normal range for non-diabetic people who are fasting should range between: 70 and 100 milligrams per deciliter (mg/dL) Non-diabetic people who ...
1
vote
1answer
2k views
3
votes
1answer
81 views

What's the use of RNA editing in kinetoplast?

The genes of the mitochondrion (kinetoplast) of some Kinetoplastida - e.g. Trypanosoma brucei, the parasite which causes African sleeping sickness - are "encoded" in a way that the pre mRNA requiries ...
1
vote
1answer
67 views

Why PPD test in patients without M.tuberculosis often slightly positive?

I got this question which I interpret as Why PPD test in patients without M. tuberculosis often have slightly positive PPD reaction i.e., a lifelong slightly positive skin test reaction? because ...
2
votes
3answers
132 views

Why HIV patients have greater virulence of M.tuberculosis?

I am reading Murray Microbiology book. Some facts M. tuberculosis is an intracellular pathogen. At the time of exposure, M. tuberculosis enters the respiratory airways and infectious particles ...
1
vote
1answer
89 views

Transcribing DNA to mRNA with introns

I have a problem in my bioinformatics class that I thought I was doing right, but someone else is getting a different answer. Here is the problem: Given the following DNA sequence, ...
0
votes
1answer
151 views

Some trophoblast excreting digestive enzymes in implantation

I found this paragraph in my study materials about implantation Original Simplest trophoblast excretes trypsin related substances and embedding consists of 3 stages: The blastocyst ...
4
votes
1answer
182 views

Why plants (eg. parsley) can keep vitamin C despite all the sun?

I have read that vitamin C is highly sensitive to light. So, how could parsley, for instance keep its vitamin C as it's flooded with sunlight?
-1
votes
1answer
59 views

What is the impact of prolonged electromagnetic exposure on human health?

What are the health effects of being exposed to a very strong electromagnetic field caused by two resonating superconductive coils (not static magnets) for a period of years?
1
vote
0answers
26 views

recombinant gametes

Suppose you are able to observe under a microscope the total number of meiotic divisions occurring in one gonad of a given individual and to outnumber exactly the crossovers between two given ...
2
votes
1answer
132 views

Transition/Transversion ratio

I'm taking a bioinformatics class and at this point we are just going over basic stuff about molecular biology. Half of the class is doing reading/research on our own, so there isn't much class time ...
2
votes
1answer
68 views

Reduction of size in diatoms due to asexual reproduction

From this we can see that diatoms reduce their size after asexual reproduction. This would ultimately lead to nonviable small size. Is there any mechanism to avoid this ?
2
votes
2answers
63 views

Connection between genes and pathways

I am reading about a paper about inferencing pathway information in cancer cells. Authors refer to ERBB2 as a gene and a pathway. I don't have solid biology background. What exactly means when we ...
3
votes
2answers
73 views

Detecting cancer or a genetic predisposition based on DNA sequencing

I am not by any means a biologist - so go easy. What would be a method for determining whether or not a patient has cancer based only on a genomic sequence? Update Thanks for the help in revising ...
1
vote
1answer
47 views

At what cancer stage do tumors release circulating tumor cells into the blood?

And would a very accurate sensitive system for detecting circulating tumor cells (which detects 1 cell per 50 billion) be useful as a screening tool ?
3
votes
1answer
82 views

Is there a database containing sequences of human cell lines?

I'm looking for the whole genome sequences of several human cell lines, e.g., A549 or Ea.hy.926. Is there a database specifically dedicated to human cell lines?
0
votes
1answer
82 views

Is “monosexual” still a valid term in biology?

I read an older article where they talk about species being strictly monosexual as opposite of being hermaphrodite, etc [1]. After an extensive googling and reading about how everybody has to be at ...
3
votes
2answers
148 views

Question about Autosomal Recessive Alleles

I had a homework question that I could not figure out. It states: A woman has cystic fibrosis in her family and did not want to have a child that suffered from the disease. She and her spouse ...
3
votes
2answers
95 views

Why are dolphins so smart?

It seems that dolphins have (among?) the highest encephalization quotients found outside of humans, higher even than chimpanzees. By the "use it or lose it" principle this indicates that intelligence ...
5
votes
1answer
430 views

What's the recommended maximum passage number for mammalian cells (NCI-H441)?

Is there a generally accepted maximum number of times you should split and reseed mammalian culture cells before restarting cultures from new stock?
1
vote
0answers
43 views

Pharmacodynamics of Ethinyl estradiol + Drospirenone and interactions with istotertinoin

Does pharmacodynamics of Ethinyl estradiol + Drospirenone in OCP pills like (Yaz, Yasminelle etc.) while using isotretinoin (Axotret, Roaccutane etc.) is changed? Does isotretinoin weakens the OCP ...
3
votes
1answer
844 views

Classification of glycosidic anomeric bonds (alpha vs. beta)

In the process of studying for my upcoming biochemistry exam, I have stumbled over the classification of glycosidic bonds. I want to be able to distinguish $\alpha$- from $\beta$-glycosidic bonds. ...
1
vote
1answer
70 views

Botany related question: liverwort sporophyte

Is perianth part of the sporophyte or gametophyte in liverworts (Marchantiophyta)?
1
vote
1answer
172 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
votes
2answers
84 views

Could a normative population ever be non-heterosexual? [closed]

In the modern documentary called "Bi the way", one American geneticist said that if modern American youngsters may as well be functionally bisexual, then some generations ahead Americans could be ...
-1
votes
1answer
107 views

Can pheromones in perfume be formulated to cause agitation? [closed]

I generally don't care for female perfume. I have very sensitive olfactory receptors and in general, I just find perfume overwhelming. A couple weeks ago, my wife of almost 14 years and I were ...
1
vote
2answers
140 views

Removing a restriction site and introducing other at its place

What would you do if you want to remove an EcoRI restriction site and introduce BamHI restriction site at apprx. the same location ? One of the answers in my textbook was : To construct a DNA ...
2
votes
2answers
101 views

Is it possible to create an experiment in house conditions to prove the existence of germs?

I realise that the best way to prove the existence of germs or single-celled organisms is by looking at them through a microscope. But I don't have a microscope at my home, how can I design an ...
5
votes
1answer
64 views

Are there baby drinks closer to breast-milk?

Many women cannot or will not feed their children with breast-milk. It is my understanding breast-milk has many advantages over formula. Some psychological like oxytocin and some physiological like ...
2
votes
4answers
153 views

Does a phenotype include the presence of a recessive gene

I am trying to understand what exactly a phenotype is to try and understand a genetics database. (Ie I don't really know very much about genetics at all) I've been reading through wikipedia on what a ...

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