4
votes
2answers
2k views

On which strand does the promoter sit?

My book keeps giving different indicators as to whether the promoters are on the coding or template strand. It says the -35 region in prokaryotes must be on the coding strand. It also mentions, that ...
0
votes
1answer
181 views

How can synonymous mutations lead to cancerous or tumorous phenotypes?

After analyzing DNA sequences of an oncogene from many human cancer patients, you found that synonymous substitutions occur in a specific codon of this oncogene. Assuming that these synonymous ...
2
votes
1answer
172 views

Why are haploid cancer cells not killed by immune system?

I have seen haploid cancer cells (I think it was leukemia cells) in a lab. Sperms and eggs are haploid but are not destroyed by the body because they are protected by other cells surrounding them. ...
3
votes
1answer
132 views

Drosophila melanogaster eclosion

Is there any published data which shows the number of Drosophila melanogaster fruit flies eclosing (hatching out of the pupae) against time since egg oviposition? I'm thinking there should be ...
2
votes
1answer
506 views

Action potential and sodium channels

In this video on electro tonic potential, the tutor says that when the potassium channels open the potential drops from +40mV to -80mV, where the sodium channels have already closed at +40mV. Now in ...
4
votes
1answer
724 views

Causes of monozygotic twins

Twins could be monzygotic i.e. identical twins and dizygotic i.e. non-identical twins.Well, monozygotic twins occur when a single egg is fertilized to form a zygote which later divide into separate ...
3
votes
1answer
946 views

Is the complement system a part of innate or adaptive immunity

I've been reading about the complement system, as part of the human immune system. The complement system is introduced as part of the article on innate immunity on Wikipedia. This classification makes ...
6
votes
1answer
113 views

Disproportion in cranial nerve innervation?

The cranial nerve innervation is highly disproportionate, as far as humans are concerned. I am not sure of the advantage of being innervated by cranial nerve versus being innervated by a normal ...
0
votes
1answer
82 views

Stomach sagittal section

Can anyone please tell me where is exactly the stomach in this image? This is a sagittal section from the University of Michigan Visible Human Browsers. Thank you.
1
vote
0answers
59 views

What are current abiogenesis hypotheses for first food source?

What is the very first abiogenetic piece of reproducing life (small piece of RNA + ribosome that randomly occurred?) hypothesized to have used as an energy source? I'd be interested in sources to what ...
1
vote
1answer
2k views

Why is prothrombin time test not used for heparin

Prothrombin time test is used for the monitoring of warfarin but not heparin. Why is this used for warfarin monitoring and why is it not used for heparin monitoring?
2
votes
1answer
51 views

Epistasis when interacting loci are codons within a single gene

There is epistasis when the effect on the phenotype of one gene is influenced by one or more other genes (called modifiers). Is there a similar concept when the effect on the phenotype of one site ...
3
votes
1answer
93 views

Activation Of Embryonic Genome

Embryonic gene activation is a process by which the embryo begins to transcribe its newly formed genome.As the embryonic gene activation occurs during early stages the paternal genome may not have any ...
1
vote
1answer
71 views

Effects of smoking tobacco compared to inhaling other smoke

How much less dangerous is breathing smoke from burning wood and coal compare to smoking tobacco? Edit: Sorry. I should have made the question clearer. If this were an experiment, it would be set ...
4
votes
1answer
57 views

Do local field potentials (LFP) create waves on the surfaces of nerve cells?

Are waves created by the LFP on the surfaces of neurons cell bodies? Since the cells have a resting potential, do these waves create harmonic oscillation of the membranes at particular frequencies? ...
1
vote
1answer
46 views

Do all animals exhibit comparable reflex velocity?

First, my exposure to biology is high-school. Should the answer to the question be obvious - please take a moment to laugh, and then point me in the right direction. A quick google search (or perhaps ...
0
votes
3answers
81 views

What is the datatype of dna sample?

What is the type of data you get when analyzing dna of a person? If you want to store them in a database, what type of field you will need (text,number,hex)? And what should be it's length?
4
votes
1answer
65 views

How much cost would artificial pollination add to common products (fruits etc.)?

I've read about ecosystem services and their possible valuation - statements like "honeybee pollination service in the US is worth 1.6 billion dollars". Is data available on how this would affect the ...
2
votes
1answer
58 views

How is it decided that one drug is better than others by X times?

I read in Tortora and Derrickson that : Enkephelins are 200 times powerful than morphine in their analgesic effects. I wonder how exactly researchers arrive at a number (like 200 here). I also ...
2
votes
0answers
178 views

Saltatory Conduction Of Nerve Impulses

I am aware about some basics of Saltatory conduction of nerve impulses. I know that the nerve impulses(ionic flow and the depolarization) are transferred from the node to the node in myelinated nerve ...
1
vote
1answer
49 views

About validation process of phenological study

I have recently done a phenological study using remote sensing techniques. Now I need to validate my results and my methods, that is, to determine if the phenology estimated from remote sensing is ...
3
votes
1answer
67 views

What is the correct medical procedure(s) for taking a resting heart rate?

Note: I thought the Biology stack exchange would suit this question better than the Fitness stack exchange. Please let me know in the comments if this is not suitable here. I am interested in ...
1
vote
1answer
516 views

Shine-Dalgarno sequence and expressing proteins

Shine-Dalgarno sequence present in the prokaryotic mRNA plays a role in initiation of translation. In eukaryotes a Shine-Dalgarno like sequence is present but does not play an important role in ...
6
votes
2answers
56 views

What features cause mechano sensory adaptation?

In relation to mechanoreceptors (e.g. pacinian corpuscles), what stops a constant stimulus from producing action potentials? I understand that adaption is used to filter out stimuli that aren't ...
2
votes
1answer
77 views

Plant tissue culture [closed]

Tissue culture means that cells are propagated and multiplied under controlled conditions. Suppose the following situations: a) A seed being is embedded in an Agar medium and germinated under ...
8
votes
1answer
112 views

Neuroendocrinal mechanism of parturition

My book reads, "The fetus signals that it is mature by secreting certain hormones that diffuse across the placenta into mother's blood and cause the secretion of oxytocin from her posterior ...
3
votes
1answer
493 views

Why are people tired after surgery?

I had surgery when woke up I felt like I only had 20% energy & felt extremely tired. Is this a common sensation? Why do people feel so tired after surgery?
1
vote
0answers
53 views

Why does the ovum prefers to be arrested at metaphase 2 of meosis before fertilization? What is the possible advantage of this process?

Why does the human ovum prefers to be arrested at metaphase 2 of meosis before fertilization? What is the possible advantage of this process??Please help me with it.
0
votes
1answer
45 views

How to monitor the use of Nootropics?

How do you monitor the use of nootropics? What is a good process to measure both: side-effects and any improvements. Where can I find resources with scientific and tested data of short and long term ...
0
votes
1answer
220 views

Scientific name for the union point of a plant stem and root

Is there a word that describes the meeting point of a plants growing stem and its root? Is this the same term for aerial roots above soil level?
1
vote
1answer
87 views

Terms related to megasporogenesis

Well, I am not able to understand the exact difference between megasporocyte and archesporium. Also I'm not quite able to get, how or precisely from where do these arise? Please help.
1
vote
1answer
75 views

Alpha wave frequency variance in EEG of single subject over period of a few hours?

I have an Emotiv EPOC (EEG headset: 128 SPS, notch filter @60 Hz, felt saline contacts) I've been playing around with. Over the course of two or three hours using CCA to plot an SNR contour against ...
2
votes
0answers
51 views

Embryo activity during seed dormancy?

What metabolic processes does a dormant embryo in a seed carry out? The newly produced seed will not germinate, either because of a lack of favourable conditions, seed hibernation, or because of a ...
6
votes
1answer
755 views

Regulation in plants bearing cleistogamous and chasmogamous flowers

In most plants bearing cleistogamous flowers, chasmogamous flowers are also borne by the plants. For example, Viola, Oxalis and Commelina contain both these kinds of flowers.( I am unaware of a ...
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 ...
1
vote
1answer
97 views

Artificial Propagation and it's relation to asexual reproduction

I know that asexual reproduction is also called vegetative reproduction. However I do not understand it's relation to artificial propagation. Is it a technique used for asexual reproduction (the ...
0
votes
1answer
49 views

Seed Germination

Is my understand of how seed germination comes to be and what it entails correct? Seed germination: As the seed matures it loses water and enters dormancy (a state in which it’s metabolic processes ...
3
votes
1answer
35 views

Seed Dormancy and Seed Transportation

My textbook says "As the seed matures it loses water and enter dormancy". I am confused as to whether this happens before the seeds are transported or after, and as to how seeds know to become dormant ...
0
votes
1answer
55 views

estradiol hormone role

Increasing estradiol (E2) hormone from ovarian follicles prior to ovulation has been hypothesized to play a critical role for induction of pheromones. These pheromones render females sexually ...
1
vote
1answer
189 views

Codon alignment via Python? [closed]

I have pairs of coding DNA sequences which I wish to perform pairwise codon alignments via Python, I have "half completed" the process. So far.. I retrive pairs of orthologous DNA sequences from ...
2
votes
2answers
76 views

Molecular simulations without capping n- and c-terminus of polypeptide

When running molecular simulations, what is the consequence of not capping the n- and c-terminus? I have been following gromacs tutorials and haven't come across any that deal with capping the ...
4
votes
2answers
112 views

Is tactile perception two-dimensional or three-dimensional?

Is tactile perception two-dimensional or three-dimensional? Can tactile sense be mapped on 2-dimensional map of the surface of the human body or does human receive tactile signal as a 3D position ...
3
votes
1answer
502 views

When happens when pollen grains land on the a part other than the stigma of a flower of the same species?

When happens when pollen grains land on the a part other than the stigma of a flower of the same species? Would the pollen be transported to the stigma or would it just sit where it landed and nothing ...
1
vote
2answers
1k views

What does dominant generation mean

In my texbook it is written that for non- vascular seedless plants the dominant generation is the gametophyte as the gametophyte generation is larger and longer lived. Is the criteria for dominant ...
4
votes
1answer
260 views

Sporophyte and gametophyte

My textbook says that in both groups of seedless plants (vascular plants, non-vascular plants) the gametophyte is a free-living plant, independent of the sporophyte. I don't understand this statement ...
1
vote
1answer
120 views

Why do some animals and fungi prefer asexual reproduction?

Animals like Sponges and Hydra and fungi like Yeast and Mushroom can reproduce both asexually and sexually. However, they only reproduce sexually if the 'circumstances' are 'bad'. Is there a specific ...
2
votes
1answer
41 views

ligand binding fluorescent protein

does anyone know of a fluorescent protein that upon binding of a substrate its fluorescence is activated? i've been looking on this and perhaps my keywords are not the right ones. Thanks in advance
9
votes
3answers
1k views

Why did abiogenesis only happen once?

If the "primordial soup" theory of abiogenesis is to be believed, self-reproducing organisms spontaneously arose on Earth at least 3.5 billion years ago, surprisingly soon after the Earth cooled down ...
2
votes
2answers
838 views

Can more than one antibody bind the same antigen

I'd like to clear something up about antibodies that I'm not sure I've understood in the articles I've read. Looking at concepts such as "affinity maturation", "monovalent antigens" and "polyvalent ...
1
vote
1answer
117 views

Studying the fruitfly nervous system

I'm studying Neuroscience and Fruit Flies are a pretty big deal but I don't know as much as I think I should about them. Are there and comprehensive sources that I could read? I'd like a review of ...

15 30 50 per page