0
votes
1answer
1k views

How to calculate biological half life of a drug that is dose dependent?

I would like to calculate the half-life of a biological drug. This biological drug is said to have a biological half-life of: ...
2
votes
1answer
40 views

MTHFR recessive alleles and B-vitamins

I know that being heterozygous or homozygous recessive for the MTHFR gene prevents that person from being able to process and use folate and B-12. It causes an unhealthy level of homocysteine to ...
5
votes
1answer
517 views

Time spent in phases of cell cycle

I am looking for references to papers containing the time intervals spent in different phases of the cell cycle (ej., G0, G1, S, G2, M for eukaryotes) for different cells. In particular, I am ...
1
vote
1answer
42 views

Mitochondrial inner membrane

I know that the cristae of the inner membrane can be tubular or vesicular but I would like to know what are the functions of each .
6
votes
1answer
117 views

Are there terrestrial plants that thrive on sea water?

Given the existence of coastal deserts such as in the picture below, I was wondering whether terrestrial plants can survive on sea water alone? If yes, why then do coastal deserts exist, instead of ...
3
votes
1answer
39 views

How high into the air are spores of molds commonly occurring?

I understand so far that most of the air surrounding us contains mold spores so that given the right environment and a food source they start to grow. I assume this is true for air close to the earth. ...
3
votes
1answer
49 views

What makes a strong polyadenylation signal a strong signal?

I was wondering why is it that "AAUAAA" is a strong Polyadenylation signal whereas the rest of the polyadenylation signals show reduced cleavage and polyadenylation efficiency?
2
votes
1answer
108 views

Consequence of Plants as Incomplete Protein Source

Some years ago, in a 1000~ level biology course we learned that the DNA essentially encodes formulas for creating proteins from amino acids. While the human body can synthesize many many amino acids, ...
11
votes
4answers
7k views

Will the heart keep beating if it is separated from the body?

The heart is a vital organ in our body, as it drives blood circulation. I was wondering if a heart keeps beating if it is separated from the body? If yes, then why?
13
votes
4answers
10k views

Are trees the only source of large amounts of oxygen?

Trees use carbon dioxide and produce oxygen in the presence of sunlight. But is there any other source? If yes, are trees the most important source of oxygen, or is there any other source which ...
0
votes
0answers
38 views

To what extent do different species of plants help each other in the defense against herbivores?

Many plant species developed the ability to sense mechanical damage and herbivory attacks. In case of such, some produces airborne chemicals (among others), to signal not only it's other parts, but ...
1
vote
1answer
78 views

Leaves growing on a leaf of a Begonia

I've a Begonia species. Somehow it started to grow new leaves on top and right in the center of an existing leaf which you can see in the center of the image. Why is it doing this? Apparently it is ...
5
votes
1answer
78 views

Identify the plant

Can anyone tell me which plant or flower is this. I have found it in Darjeeling, West Bengal, India.
2
votes
1answer
71 views

How do I find the number of child terms associated with a specific GO term?

I am trying to figure out how to find the number of child terms associated with a specific Gene Ontology (GO) term using QuickGO, without just counting the amount of terms in a list. For example when ...
3
votes
0answers
43 views

Expected reproduction rate of a dandelion and/or fern

I am working a basic mathematical/computer simulation of an ecosystem, and I need to know the birth rate of each organism in my simulation. However, I could not find any data for how often a small, ...
17
votes
3answers
6k 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
0answers
58 views

Is there a comprehensive model of human attraction and sexuality? [closed]

I'm interested if modern (2015) biology has a comprehensive model of how human sexuality works. From my research, it appears that the drive for mating is primarily mediated by ...
0
votes
1answer
112 views

How can succinylcholine cause myorelaxation?

I first thought that this is because of prolonged depolarisations. However, I am not sure anymore, because after reading PubChem, the only possible pathways are are Choline agonist. So I would say ...
5
votes
1answer
42 views

One Sample, Different Methylation Values

I'm hoping that somebody here can explain this unusual result that I'm getting with some pyrosequencing data. I have bisulphite converted a few samples a couple of times over the years for different ...
2
votes
2answers
217 views

Value of mathematical models in biology [closed]

Sorry if this is too much of a soft question or if it is too broad for this site. As a person who has much more experience with math than biology, I've always been really interested in the ...
1
vote
0answers
31 views

Can photosyntetic cells be genetically modified to grow at a faster rate?

I hope the question is not silly, but I wonder if a sort of genetically modified plant "cancer" could be used for carbon sequestration. For example, cancer cells like HeLa have been reproduced in ...
0
votes
1answer
384 views

Choosing a book to gain general knowledge about biology [duplicate]

I will be first year undergraduate at Physics department next year and last year I was at the Medicine faculty. I want do double major in the second year of faculty with Molecular Biology and ...
21
votes
2answers
2k views

Can rats pass on memories of a maze to their offspring?

A friend of mine told me once about a documentary movie he saw some years ago. On this movie he saw scientists talking about particular experiment. This experiment involved rats and probably ...
3
votes
2answers
264 views

Neomycin resistance gene in E. coli stb3 cells

We use a lentivirus packaging vector called pLenti_puro_DEST. We use puromycin to select for the cloned gene in 293T cells. However, the pLenti_Neo_Dest has been discontinued, so I'm cloning a ...
3
votes
0answers
19 views

Gene silencing: relative or absolute number of methylated CpG sites?

CpG content varies a lot across the human genome. What does determine a promoter to be silenced through DNA methylation: the fraction of CpG sites that are methylated or the total number of methylated ...
4
votes
2answers
2k views

Is secondary follicle or Graafian follicle arrested in the second metaphase of oogenesis?

My note about which I am not sure: Secondary oocyte is arrested in the metaphase II monthly after puberty until fertilization with sperm. The following picture also satisfies my sentence: . So ...
4
votes
1answer
129 views

Is the autonomic nervous system only activated by internal stimuli?

My professor claims that the autonomic nervous system is only activated by stimuli from organs but I really feel like I've read that it can be activated by outside stimuli, although I'm not sure what ...
11
votes
2answers
462 views

Can we make a rough estimate of the number of generations since the origin of life?

According to what we've learnt : we can approximate the number of generations since the first human pretty much like us (depending what / who we talk about). we have an idea of the series of life ...
3
votes
1answer
158 views

Pigmentation in Jaundice

My textbook says that the yellow appearance of a jaundiced person is due to the accumulation of bile pigments in the skin. I am unable to understand why these pigments are not deposited in a healthy ...
4
votes
1answer
210 views

Why do some protocols require prewarming a liquid medium before inoculating?

For example, in this protocol for E. coli competent cell preparation, it says: Plate 10 uL E. coli BL21(DE3) cells on a LB-agar plate; incubate overnight (12 hours). Prepare 500 mL SOB medium ...
3
votes
2answers
174 views

What species is this worm? [closed]

I was at the park lying on the grass and its the third time I have seen them, I used to think they were parasites when I was like 7. It is the very small brown worm on the green leaf. It moves by ...
11
votes
1answer
144 views

What limits chromosomal length?

What are the upper and lower limits for chromosome length? Are these limits different in different species or kingdoms? If there is any limit, which cellular or molecular factors are reasons?
2
votes
1answer
92 views

Additive genetic variance $V_A= 2pqa^2$ … what is $a$?

Reading Falconer and Mackay looking at equation $V_A = 2pqa^2$ (equation 8.5, page 126). I am trying to write a clear explanation of how additive genetic variance is defined and calculated, but I ...
7
votes
0answers
239 views

What bacteria shed harvestable energy from root zone organic matter?

I recently heard of a successful effort that harvests energy from soil at plants' bases due to apparently bacterial breakdown of wastes from the plants: Via photosynthesis a plant produces organic ...
-3
votes
1answer
68 views

From where can I download the database created by Hsu et al for MORFs? [closed]

I am working on an independent research project for which I require access to the MORF database created by Hsu et al. From where can I download the database of MORFs of IDPs and their binding partners ...
2
votes
0answers
69 views

Falconer & Mackay population mean calculation & genotypic values

I am reading chapter 7 of Falconer and Mackay where they give a formula to calculate the population mean as a deviation from the heterozygote genotypic value. As an example, imagine a one locus two ...
1
vote
1answer
134 views

How Scientists sequence, assemble and annotate plant genomes? [closed]

I previously read this question and this paper and learned good things about this topic. my current question is that scientists use which tools, algorithms, soft wares... to sequence, assemble and ...
2
votes
2answers
226 views

Cleavage of RNA by restriction enzymes?

Six restriction enzymes discussed in Sequence-specific cleavage of RNA by Type II restriction enzymes (Murray et al.) have the ability to detect and cut RNA strands with that enzyme's recognition ...
6
votes
1answer
174 views

What are the psychedelic effects of (star) anise and how many people are affected?

Backstory: My girlfriend reacts heavily to chocolate and drinks containing stellar anise, in a way that seems comparable to psychedelic drugs. After consuming it, it takes approximately five minutes ...
2
votes
1answer
69 views

What is this plant on the photos?

Found in Kustaankartano, Helsinki, Finland in June 2015. (for closeup view, copy image URL and open in new window and then zoom in)
5
votes
1answer
71 views

The ermine's colour and geographical range

Ermines turn white during the winter, with only the tip of the tail remaining black. However, in the southern regions of the ermine's range it clearly doesn't get so white. Encyclopedia of Life says ...
2
votes
1answer
79 views

Better population models than the logistic equation [closed]

For modelling the population of a single species in a region, the logistic equation is used $$ \frac{dN}{dt} =kN\Big(1-\frac{N}{K}\Big) $$ where $N$ is the number of organisms, $K$ is the carrying ...
1
vote
0answers
706 views

What's the difference between blood value units 'mE/l', 'mU/l', 'mIU/l' and 'mEq/l'?

Wikipedia suggests 'mE/l' is the dutch or german translation (using 'eenheid'/'einheit' for 'unit') for 'mU/l', which can also be written as 'mIU/l'. The article mentions ...
2
votes
1answer
62 views

Can Opioids Attenuate some of the symptoms of Psychosis?

Can Opioids Attenuate some of the symptoms of Psychosis? I ask because there's a dead link on the Wikipedia page that's meant to support the notion that opioids attenuate some of the symptoms of ...
8
votes
1answer
261 views

What is this insect that has invaded my home in Texas?

After the recent floods in central Texas this past weekend I noticed my that bedroom has suddenly been infested with these small insects that have climbed in through the window. Previously, the hole ...
6
votes
1answer
740 views

Does inhaling glue (glue sniffing) reduce appetite?

I have heard from many homeless people that they sniff glue just to reduce appetite, as it comes cheap and is more affordable than actual food. Is this true, and if yes, why? This is totally opposite ...
5
votes
0answers
53 views

Is hunger pushing cognitive ability in humans? [closed]

We have a lot of those questions here that base on personal anecdotes and I try to avoid asking any of those. Still, after skipping breakfast and an extremely effective work day so far I started ...
11
votes
2answers
29k views

Why is SOC medium recommended for transformations?

In pretty much every transformation protocol I've seen SOC medium is used to grow the bacteria for a short while after the tranformation and before plating. I've usually substituted LB medium for ...
3
votes
0answers
163 views

Can I leave BL21(DE3) cells in room temperature?

I am preparing competent cells, and I finished inoculating a single colony in SOB. It has been incubating at 37 degrees Celsius for almost 16 hours since, and it's getting very late where I live. I ...
6
votes
1answer
62 views

Are there medical treatments that were so effective they were never subjected to a randomized control trial?

I'm thinking of things like antibiotics for meningitis or tuberculosis, or thiamine for Wernicke-Korsakoff syndrome. In those cases the magnitude of the treatment effect might have been so great that ...

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