0
votes
1answer
118 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
22 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
261 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
39 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 .
5
votes
1answer
50 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 ...
2
votes
1answer
46 views

GATK workflow for Cancer

I am just starting to learn to use bioinformatics tools. My university has a limited and expensive bioinformatics team, so I'm mostly on my own except for big questions. I am planning to use GATK to ...
2
votes
1answer
30 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. ...
10
votes
2answers
5k views

Why do we assume that the first humans were dark-skinned?

According to the article Dark skin and blue eyes: How Europeans once looked: It is widely accepted that Man's oldest common forefather was dark skinned, and that people became more pale as they ...
6
votes
0answers
31 views

What is the fate of micronucleus DNA?

Micronuclei are cellular structures that are formed as a by-product of, usually, defective mitosis. The piece of chromosome in a micronucleus may, or may not contain a centromere and the DNA is ...
3
votes
1answer
38 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
69 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
1k 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?
11
votes
4answers
3k 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
24 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 ...
3
votes
2answers
82 views

Do variant callers miss rare variants in reference?

Generally variant calling programs (such as GATK-UnifiedGenotyper) look for differences between reference genome and submitted sequence. However, we all know that reference genome consist rare ...
3
votes
1answer
57 views

How many traits can a multivariate breeders equation handle?

The multivariate breeders equation (MBE) by Lande predicts the change in a trait $\Delta \bar z$ (response) as $\Delta \bar z = G \beta$ where $G$ is a genetic variance-covariance matrix and ...
1
vote
1answer
44 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 ...
4
votes
2answers
152 views

How is photosynthesis observed?

How is photosynthesis observed? Say I have plants A and B, and I want to find how fast they are able to turn carbon dioxide into oxygen. How would I experiment this? Say I have one plant A, which ...
4
votes
1answer
64 views

Identify the plant

Can anyone tell me which plant or flower is this. I have found it in Darjeeling, West Bengal, India.
3
votes
1answer
89 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 ...
2
votes
1answer
41 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 ...
4
votes
1answer
68 views

Criteria for compound action potential thresholds

As opposed to action potential thresholds (which are binary yes/no events), electrophysiological thresholds of compound action potentials are arbitrary. Mostly a certain noise level is picked and when ...
3
votes
1answer
91 views

Examples of Vestigial Genes

I consider the existence of a broken GULO gene in humans to be the clearest evidence for human evolution - just what else is it doing there otherwise? Are there any other examples of vestigial genes ...
3
votes
0answers
28 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, ...
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
0answers
35 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
82 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
38 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
110 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
26 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 ...
-1
votes
1answer
72 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 ...
5
votes
2answers
40 views

Can a woman possessing 1 mutated allele show attenuated color-vision deficiency?

Women possess two X chromosomes. However, during development, when the embryo has about 32 - 64 cells, one of these chromosomes is randomly inactivated (in each cell) by an lncRNA named Xist. As a ...
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
50 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
14 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
1k 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 ...
5
votes
1answer
87 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 ...
4
votes
1answer
40 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
106 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
120 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
32 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
146 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 ...
5
votes
1answer
41 views
11
votes
1answer
70 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
47 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 ...
6
votes
0answers
34 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 ...
6
votes
0answers
35 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
27 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
26 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 ...
2
votes
1answer
37 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 ...

15 30 50 per page