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, ...
5
votes
2answers
2k views

Do we need to drink less water in humid weather than in dry weather?

From my understanding, humid weather means that the air has a lot of water in it. Therefore, someone who lives in this kind of weather would be hydrating himself just by breathing. Does that mean ...
5
votes
1answer
79 views

Identify the plant

Can anyone tell me which plant or flower is this. I have found it in Darjeeling, West Bengal, India.
1
vote
0answers
59 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 ...
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 tons,...
7
votes
1answer
343 views

What determines the number of chromosomes an organism carries?

This is an extension of this question about What limits chromosomal length?. I am wondering what could be the specific reasons behind the number of chromosomes an organism carries. In other words, ...
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 ...
3
votes
2answers
277 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 ...
0
votes
1answer
406 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 Genetics....
4
votes
1answer
238 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 ...
11
votes
1answer
146 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?
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 ...
7
votes
3answers
104 views

Following DNA replication during S-phase of the cell-cycle, are all genomic regions subjected to the same stringent level of DNA-Repair?

To my (limited) understanding, there are 2 main ways that mutations can occur in DNA: Environmental (UV, etc) and mistakes during cell division. I was wondering if there is a mechanism that can give ...
7
votes
0answers
242 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 ...
2
votes
1answer
100 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 ...
-3
votes
1answer
69 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
74 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 ...
6
votes
1answer
193 views

Can androgen-insensitive genetic-males get pregnant?

According to the linked report, people with androgen insensitivity syndrome appear as male, but have both feminine and masculine outer genitalia. However, I was not able to find out whether their ...
3
votes
1answer
68 views

Where is ATP used in Phosphorylation?

In the section describing the Calvin Cycle, under the subheading "Reduction", my textbook states that: The steps involve utilisation of 2 molecules of ATP for Phosphorylation... I could not get ...
3
votes
1answer
159 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
134 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 ...
8
votes
1answer
3k views

How should species density be calculated for a clumped distribution?

Lets imagine 5 plots of different size are sampled for a target species: ...
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)
6
votes
1answer
252 views

Sequence evolution simulation tool

I'm looking for a tool to simulate sequence evolution given a specific mutation model and birth-death model. I'm aware of tools and packages like INDELible, Seq-Gen and PhyloSim, but they simulate ...
1
vote
1answer
137 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 ...
1
vote
0answers
737 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 ...
5
votes
0answers
54 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 ...
8
votes
1answer
811 views

What dragonfly is this?

I photographed a dragonfly but can't really identify the species using http://www.libellen.tv/. Are there any other resources I could use? The pictures were taken in early June, around 11:00 next to ...
3
votes
0answers
172 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
756 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 ...
6
votes
1answer
64 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 ...
8
votes
2answers
2k views

Why pick just a single bacterial transformed colony

So after bacteria have been transformed to perhaps grow up a plasmid of interest, why pick only a single bacterial colony from a selective plate for further expansion? I understand that this is to ...
5
votes
1answer
75 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 ...
10
votes
1answer
911 views

Do I not have any alleles from my mom's mom & my dad's dad?

So, I have an XX, & I got an X from my mom, & an X from my dad. My dad would have gotten his only X from his mother, & my mother could have gotten the X I got from her father or mother. ...
6
votes
1answer
93 views

How many dinosaur genes are in a chicken genome?

I read recently that we can "work back" to a dinosaur by selectively turning off certain genes in chickens, and we were able to create a chicken with a snout instead of a beak. How many dinosaur ...
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
133 views

Does Acromegaly cause actual expansion of the zygomatic(cheek) bone

Acromegaly is a disorder in adults involving excess growth hormone production. Since epiphyseal fusion has already taken place in most bones of adults , this does not cause an increase in stature. ...
1
vote
0answers
31 views

Load specific sequences in with BioSeqIO [closed]

I am trying to load a multifasta file with Perl using my $in = Bio::SeqIO->new( -file => $entrance) and then I loop trhough the file looking for id i ...
4
votes
2answers
133 views

Why do negative ions flow into a cell in an inhibitory synapse, even though a neuron has a negative resting potential?

In my spare time I have been reading an introductory Psychology textbook and this question came to my mind after reading about action potentials. I have no previous knowledge in chemistry so if I do ...
3
votes
1answer
56 views

How do cold conditions help organ transplants?

Body organs are kept cold in-between explanting them from the donor and implanting them in the new host. How do these cold conditions help organs to stay viable while they haven't fresh blood, energy ...
2
votes
2answers
291 views

How to grow fibroblast colonies from single cells?

I need to establish a cell line starting from single cells seeded on a 96 wells plate by a FACS sorter. The cells I am using are human fibroblasts RPE-1 cultured in F12 medium supplemented with 10% ...
6
votes
1answer
437 views

Isogametes and oogametes

I have found the following definitions of different types of gametes: isogametes: gametes looking and behaving the same; heterogametes: gametes different in size or in behaviour; oogametes: gametes ...
4
votes
0answers
117 views

Mating types in fungi (and somatogamy)

I would have some related questions about the mating types of fungi. Does a single spore generate a mycelium possessing only one mating type? If it does not in general, do Ascomycota and ...
2
votes
1answer
412 views

Explanation of protocol in DNA extraction experiment

In the Materials and Methods section of this paper on DNA extraction and analysis from hair I do not understand some parts of their protocol methods. In particular: "The digested hair solution was ...
1
vote
1answer
322 views

How much heat can a human sustain? [closed]

For how long can a human sustain a temperature of 180 degrees Fahrenheit (82oC) without damage in a confined place? For instance, suppose a person is sitting in a steam-filled room, without external ...
9
votes
2answers
1k views

What kind of beetle is this?

I live in Denmark, Europe and I found this insect wandering around in my garden the other day. It's some kind of beetle but i dont know what kind it is or the species. The beetle could also fly and ...
12
votes
1answer
603 views

What is the scientific name of this plant?

I found this one on a hill here in Palestine. It's about 20 cm in height. Note that it does exist in this regions, but scantily.
6
votes
4answers
7k views

Do plants with non-green leaves have chlorophyll and photosynthesis?

Is it even possible that plants with non-green leaves have chlorophyll, and do such non-green leaved plants carry out photosynthesis?
4
votes
2answers
179 views

Can carnivores survive on a (processed) vegetarian diet? Why or why not?

There are many differences in for example the digestive system between carnivores, herbivores and omnivores. It seems that in certain kinds of species adaptability with respect to diet is possible. ...
0
votes
1answer
224 views

How does amiodarone act as an alpha and beta blocker?

Amiodarone is potassium channel blocker but also voltage-gated Na+ channel blocker according to Pubchem. However, upon reading my notes I discovered Amiodarone blocks potassium channels and block ...

15 30 50 per page