7
votes
1answer
4k views

Why is fructose not glucose the main energy source of sperm?

The seminal fluid contains fructose as the main energy source for the sperm and not glucose. Why is fructose and not glucose the primary energy source for these sperm, since glucose is the ...
2
votes
1answer
61 views

List authors (scientists) by various attribute

Is there an easy way to list authors of biology articles by University country number of published articles sum of citations of all articles he/she wrote fields of study (population genetics) ... ...
2
votes
1answer
103 views

Can a plant be programmed to produce any arbitrary object?

I'm wondering if a plant can be programmed (by modifying its genes) to grow into any shape that it's programming instructs. I understand that a plants genes are its instructions of how to convert the ...
3
votes
1answer
120 views

Why insects are so small compared to mammals?

I was wondering what biological limitations make the dimension of the insects small compared to the dimension of the mammals. I know in other eras insect were bigger!
2
votes
1answer
168 views

Scrotal temperature and vascularization

The testes (at least in human males) are vascular organs, the vascularization extending even o the interstitial spaces of the seminiferous tubules. The function of the scrotal sac, is to isolate the ...
3
votes
1answer
1k views

Is the Michael Jackson skin pigmentation disease realistic?

Quoting wikipedia: Jackson's skin had been a medium-brown color for the entire duration of his youth, but starting in the mid-1980s, it gradually grew paler. The change gained widespread media ...
0
votes
1answer
201 views

Why can CO₂ be transported dissolved in plasma?

Is it because CO2 is more soluble in water or has it got to do with the alkaline pH of plasma ?I here mean only aqueous CO2 transport from body cells to lungs.
2
votes
2answers
294 views

Homework : Sodium Potassium pump

Why does sodium-potassium pump consume about 2/3 energy of a cell ? A.maintains appropriate membrane potential B.helps in co-transport I think it should be A.
4
votes
1answer
1k views

Basic step by step methods for PCR & Gel electrophoresis class

I'm teaching a class how to do PCR & gel electrophoresis soon and would like it if you could check through my basic step by step instructions - it's a while since I've done one. Is there anything ...
0
votes
1answer
53 views

Proportion of amino acids from a random polymer of U and C

A protein synthesis assay was carried out in vitro. A polyribonucleotide containing U and C in proportion 1:5 (positions of U and C are random) was used as a template. Which amino acids and in ...
1
vote
0answers
15 views

Which pathways/mechanisms could control some Synaptic clefts in series by Somatic Nervous System?

I listened a talk where the speaker said that this can probably be possible by Weak Quantum Cognition Theory. I see that there is no evidence at the moment, only theory. I see no pathways by which ...
2
votes
0answers
18 views

Gliotoxin ingestion and actions needed [closed]

what are the "next day" actions that one has to take, when accidentally ingests contaminated drink/food from Aspergillus or Penicillium or Candida fungus? Is it feasible to take N-acetyl-L-cysteine ...
2
votes
1answer
857 views

Telomere shortening during replication

It is widely know that each cell cycle during DNA replication some fraction of the telomeres is lost, and this phenomenon is called the end replication problem. Well this is due to the fact that the ...
2
votes
1answer
417 views

Why does caffeine consumption cause one to urinate more?

What is the physiological mechanism behind the diuretic effect of caffeine?
1
vote
1answer
121 views

explanation of conjugation experiment in bacteria

In this paper (On the expression of a structural gene) I am confused about what is being plotted in Figure 6. The x-axis contains the fraction of radioactive day and y-axis contains the enzyme ...
1
vote
1answer
164 views

Why is the 4.4 kb band barely visible in this HindIII digest of lambda DNA?

Why is the 4.4 kb band barely visible? Also, what is the mass (ng) of DNA in band X if lane S contains 250 ng of digested lambda phage DNA?
4
votes
2answers
310 views

Why are antibodies so expensive?

The amplification on vector transgenic microorganisms and the subsequent purification does not seem that complicated. Also, what are the processes that biotechnological industries follow, in detail, ...
4
votes
1answer
188 views

What makes a DNA sequence motif a DNA sequence motif?

I've read about DNA sequence motifs, but still don't understand what makes some sequence a DNA sequence motif. Is this a well-defined concept? For, example, What are DNA sequence motifs? says: ...
1
vote
1answer
78 views

A wierd looking fish with a shield

I have found this photo in a local news page. The page claims that this fish is a new species that was found by a Malaysian fisherman. Is this true? or it is a known fish and it has a name already?
1
vote
1answer
86 views

Body's decomposition

Does a human body decompose in a completely sterile environment ? If yes, what decomposes it ? And how fast ? What happens in vacuum ? Can it remain exactly the same ? Thanks
5
votes
1answer
181 views

Why are interspecies hybrids so often larger than either parent species

Recently doing a little reading on interspecies hybrids I noticed that it seems interspecies hybrids are most often much larger than either parent. Notably, Ligers, Dzo and Savannah Cats, but it ...
0
votes
2answers
4k views

Will I grow taller? How can i tell? [closed]

I'm 17 and I'm about 160 cm and my weight is 47 kg . I just want to know if I will still grow taller ?
2
votes
3answers
97 views

How to define “evolution”?

The standard answer to: what is evolution? is: It is a change in allele frequency over time! I believe a complete definition should encompass the following concepts: mutations copy ...
2
votes
1answer
77 views

What is one Botulinum toxin medical unit?

How many Botulinum toxin molecules or grams are contained in one medical unit of Botox?
1
vote
1answer
140 views

Standardized Selection Ratio (SSR)

In this article the athors used the Standardized Selection Ratio (SSR) in order to infer what is the preferred host (anemone) of anemonefish. Here is a quotation coming from their methods: ...
3
votes
1answer
92 views

Why does hypertension occur in obstructive sleep apnea?

What is the physiological mechanism behind systemic hypertension resulting from obstructive sleep apnea?
1
vote
1answer
288 views

Microarray gene expression matrix format

After scanning the microarray chip we get RAW data with different formats depending on the type of microarray used. However, these RAW data files can be normalized and processed to generate gene ...
1
vote
0answers
98 views

Workflow for batch analysis of ROI in histology samples

This is a pretty big task, and I have several work-arounds, but I am looking for an efficient way to go from PAS stained slides of lung tissue to defined ROI's over the whole slide (presumably via ...
3
votes
1answer
68 views

mRNA with Pseudouridine and 5-methylcytidine?

I am making mRNA by in vitro transcription for transfection purposes. There is a lot of literature about how protein expression is increased and innate immune activation is decreased by substituting ...
5
votes
1answer
186 views

Definitions and examples of some math-releated ecology branches

I would like to have an example of application and a brief description/definition (two or three lines) of the following fields. I would like to understand the exact differences between them. Other ...
3
votes
1answer
785 views

Index of ecological niche overlap

For this question I am interested in the Pianka's Index of ecological niche overlap. What is the Pianka's Index? How does it work? How can one calculate this index? How often is it used? In what ...
6
votes
0answers
108 views

At which step apply a detection filter when preprocessing microarray data? (Before/After normalization, batch effects removal)

I am trying to understand what is the best practice when preprocessing microarray data using a detection filter (on scanner p-value). Suppose I have a microarray dataset that I have to normalize with ...
1
vote
0answers
115 views

Which is the best way to fix and preserve comet assay slides before staining with Ethidium Bromide?

I want to use the method of Single Cell Gel Electrophoresis (comet assay). I have many samples, but I don't have the appropriate microscope. So I have to preserve my slides until the time comes for ...
3
votes
2answers
4k views

Difference between CDS and cDNA

What is the difference between Coding Sequences (CDS) and cDNA? Are Coding sequences the sequences that is transcribed to mRNA and cDNA in contrast DNA obtained by reverse polymerization of matured ...
5
votes
1answer
428 views

Do ants within a colony ever fight or come to conflict?

I'm investigating how hierarchical groups of a larger organization with a common goal tend to come to conflict with one another over time. As you decompose a large group (for example a corporation), ...
3
votes
1answer
87 views

Transposons and the net amount of DNA

The retrotransposons and certain DNA-transposons, are "jumping" sequences which may be incorporated elsewhere in the genomic DNA of an organism, through varying mechanisms. This insertion is almost ...
5
votes
1answer
199 views

Measuring algae growth or death

My daughter (10th grade) is doing a science fair project on the toxicity of triclosan for the algae Selenastrum capricornutum. She is wondering the best way to measure the effect, given the limited ...
2
votes
0answers
248 views

Image Processing Suite for bacterial microscopy: Schnitzcells or MicrobeTracker?

I am looking to start doing some work tracking the size and growth of individual bacterial cells in the microscope. In order to analyze the images I need software that can segment the cells, ...
4
votes
1answer
316 views

Are wild cats the same species as house cats?

I thought that the definition of species is "can interbreed" From Wikipedia: The wildcat (Felis silvestris) is a small cat found throughout most of Africa, Europe, and southwest and central ...
1
vote
2answers
151 views

Which statement about phenotypic plasticity is false?

This was a test question, and I'm not too sure about the answer. Which statement about phenotypic plasticity is false? a. Because the plasticity of a phenotypic trait may be costly to maintain, it ...
4
votes
1answer
60 views

Generalism - specialism index in microbial ecology

I am doing research in Lipid metabolism in different yeast species and I would like to look into ecology of them. I would like to classify them to a Generalist/specialist based on different ...
5
votes
2answers
146 views

Measuring fitness / lifetime reproductive success (LRS) in Drosophila

I am planning a fitness assay of Drosophila melanogaster. I'd like to get a good measure of lifetime reproductive success (lrs) but I don't want to count all the offspring produced over a lifetime by ...
1
vote
1answer
383 views

How to determine if a plant is autotrophic or heterotrophic?

How do you determine if a plant is autotrophic or heterotrophic, and are there any traits in particular that can be used to classify species? As two examples, how should Melampyrum pratense and ...
0
votes
0answers
44 views

Is there a limit to how much concise information a human can learn adequately? [duplicate]

Like, I am trying to learn more chemistry, but also computer programming from the higher-level programming methodologies, frameworks, languages, APIs, XML, web development, and I'm also hoping to ...
2
votes
0answers
45 views

Shortest route for a Nitrogen atom from fossil fuel to a protein in your body? [closed]

Millions of years ago fossil fuels originated from plants. A nitrogen atom from fossil fuel is now inside in a protein molecule in your body. What is the shortest path that the nitrogen atom ...
2
votes
0answers
27 views

How closely correlated is the level of an snRNA with the level of its corresponding snRNP?

Let's say I am growing cells under two conditions, and let's say I measure U1 snRNA levels in both using digital PCR. If the U1 snRNA level is reduced in one sample, how safe is it to say that U1 ...
5
votes
1answer
166 views

Strange looking mushroom found in a dead tree

I'm trying to identify this mushroom my sister found at her campus' lawn. It is brown, looks somewhat like a turtle or a brain and is growing inside of a dead tree trunk. Geographically the campus is ...
1
vote
1answer
168 views

Energy flow in an ecosystem

What are the mistakes in here? The image below shows a part of the energy flow diagram in an ecosystem. 1. Part P of the biomass of the primary producers does not get consumed. Give a concrete ...
3
votes
3answers
196 views

How to learn molecular biology through pubmed research articles?

Instead of using a textbook, is there an alternative curriculum, that simply lists a set of pubmed research articles for each topic covered in a typical undergrad molecular biology course? I am ...
1
vote
1answer
273 views

Genetic variation and sensitivity of wild cabbage

1: Is it true that the genetic variation of kale plants is smaller than wild cabbage? I think so, because of human selection of the kale plants. 2: Are broccoli and cauliflower more ...

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