0
votes
1answer
170 views

Can you approximate Cardiac Output by Ohm's law?

I found this sentence from my notes which I cannot understand PR < CO, CO $\uparrow$, PR > CO $\downarrow$ where ...
1
vote
1answer
90 views

In vitro transcription, contamination problem

I am using a RNA which is in vitro transcripted before I started my project. It turned out it is not prepared properly and has DNA contamination. Instead of perform the in vitro transcription again, ...
3
votes
2answers
148 views

Question about Autosomal Recessive Alleles

I had a homework question that I could not figure out. It states: A woman has cystic fibrosis in her family and did not want to have a child that suffered from the disease. She and her spouse ...
4
votes
0answers
172 views

How do duplicate brain regions (ex: left/right amygdaloid body) operate together?

I frequently hear talk about parts of the brain like "Amygdala" or "Hypothalamus", so I looked them up in an app called "essential anatomy". What I see is that there's mirror symmetry, and most of ...
-1
votes
1answer
88 views

Can nature create codes and specified complexity? [closed]

Is there an example of nature creating codes or specified complexity? It is said by Creationists that codes can only come from minds, and since DNA has a code, it was created by a mind. Is this true? ...
0
votes
1answer
49 views

An over-simplified model of cell division and its relation to stem cells

I am a mathematician, and I decided to try to model cell division with math and see what conclusions came out of it. I had some questions concerning stem cells that came up in the model. In an ...
1
vote
1answer
80 views

Dilution question about RNA

I have a basic and probably silly question. I am isolating RNA with TRIzol. I have performed the basic steps and dissolved the pellet in 50 uL water. I ve measured the concentration and it was 3313 ...
2
votes
2answers
6k views

How do trees use Adhesion and Cohesion to move water against gravity?

I have an AP Bio class where I have to name 3 properties of water and I chose adhesion and cohesion for one of them. I'm having trouble finding out how exactly trees use adhesion and cohesion to move ...
1
vote
1answer
1k views

How do the first and second law of thermodynamics adhere to breakdown of glucose?

I know the first law is energy can only be converted from one form to the other, therefore in the breakdown of glucose 40% potential energy is converted to ATP and 60% is converted to thermal and ...
1
vote
1answer
79 views

Physiology of skin and leather: why do salt borders occur?

I discussed a leather store about the white border aka salt border on leather shoes. They said that it is due to inner features of leather and you could try to add some fat/cream to push it back ...
3
votes
1answer
80 views

What's the use of RNA editing in kinetoplast?

The genes of the mitochondrion (kinetoplast) of some Kinetoplastida - e.g. Trypanosoma brucei, the parasite which causes African sleeping sickness - are "encoded" in a way that the pre mRNA requiries ...
0
votes
1answer
73 views

Difficulty in developing certain vaccines

I have a college level background in Biology, say at the level of Campbell. I am very curious to know why it's extremely difficult to develop vaccines for certain diseases. Two cases which I am really ...
2
votes
1answer
882 views

Valves in the heart

I am confused regarding the presence of valves in the superior vena cava. The superior vena cava does not possess valves unlike inferior vena cava, which possesses Eustachian Valve. Then where are ...
8
votes
2answers
3k views

why is AUG the initiation codon?

Is there any reason why AUG is the initiation codon ? Why is there a need for an initiation codon ? Can't translation start with different codons?
0
votes
1answer
149 views

Some trophoblast excreting digestive enzymes in implantation

I found this paragraph in my study materials about implantation Original Simplest trophoblast excretes trypsin related substances and embedding consists of 3 stages: The blastocyst ...
0
votes
2answers
226 views

Rh factor and dominance of gene

"Formation of Rh antigen is controlled by dominant gene(R) and its absence by recipient gene(r).People having this antigen with genotype (RR or Rr) are called Rh positive and those whose blood ...
1
vote
1answer
89 views

Transcribing DNA to mRNA with introns

I have a problem in my bioinformatics class that I thought I was doing right, but someone else is getting a different answer. Here is the problem: Given the following DNA sequence, ...
4
votes
1answer
439 views

Effect of single nucleotide deletion or insertion on primer annealing

How is primer annealing, and, consequently, PCR amplification affected by single nucleotide deletion or insertion inside the primer ? Imagine a primer like this: GCGTCATAAAGGGGACGTG (primer) and ...
3
votes
1answer
143 views

Real-time PCR delay in Cq due to insertion SNP in primer

I am collecting evidence, even anecdotal, how does single nucleotide deletion or insertion in primer region affect the outcome of real-time PCR. I am most interested in how much there is a delay in ...
7
votes
1answer
133 views

Any food crops that could grow in a desert provided that they get fertilizer and water

I am working on an idea to provide nearly unlimited amounts of water in desert regions. To make this commercially viable. I would use the water to irrigate desert sand and grow crops. Given my ...
3
votes
2answers
73 views

Detecting cancer or a genetic predisposition based on DNA sequencing

I am not by any means a biologist - so go easy. What would be a method for determining whether or not a patient has cancer based only on a genomic sequence? Update Thanks for the help in revising ...
5
votes
1answer
209 views

Improving transformation efficiencies- induce supercoiling?

From my limited knowledge of science, I know transformation can be one of the hardest step in cloning, and that a large amount of research/trial and error has been done to improve on this step. I've ...
4
votes
1answer
182 views

Why plants (eg. parsley) can keep vitamin C despite all the sun?

I have read that vitamin C is highly sensitive to light. So, how could parsley, for instance keep its vitamin C as it's flooded with sunlight?
1
vote
0answers
26 views

recombinant gametes

Suppose you are able to observe under a microscope the total number of meiotic divisions occurring in one gonad of a given individual and to outnumber exactly the crossovers between two given ...
2
votes
2answers
62 views

Connection between genes and pathways

I am reading about a paper about inferencing pathway information in cancer cells. Authors refer to ERBB2 as a gene and a pathway. I don't have solid biology background. What exactly means when we ...
4
votes
2answers
202 views

Why and how does complexity usually tends to increase through time?

The question of complexity is classic in the very first lectures of evolutionary biology where the teacher usually tries to tell the students that complexity does not necessary increases and that ...
2
votes
1answer
130 views

Transition/Transversion ratio

I'm taking a bioinformatics class and at this point we are just going over basic stuff about molecular biology. Half of the class is doing reading/research on our own, so there isn't much class time ...
2
votes
1answer
68 views

Reduction of size in diatoms due to asexual reproduction

From this we can see that diatoms reduce their size after asexual reproduction. This would ultimately lead to nonviable small size. Is there any mechanism to avoid this ?
4
votes
5answers
588 views

What is a good miniprep protocol for the class room?

I'm trying to find a good protocol for plasmid minipreps and I'm looking at 3 preps I've found: Using phenol/chloroform extract with phenol:chloroform:isoamylalcohol, isopropanol precipitation, ...
1
vote
0answers
43 views

Pharmacodynamics of Ethinyl estradiol + Drospirenone and interactions with istotertinoin

Does pharmacodynamics of Ethinyl estradiol + Drospirenone in OCP pills like (Yaz, Yasminelle etc.) while using isotretinoin (Axotret, Roaccutane etc.) is changed? Does isotretinoin weakens the OCP ...
7
votes
2answers
170 views

The Assumption of Weak Selection?

I was reading this question and I failed to fully understand the introductory part of it. The OP (@Artem Kaznatcheev) says: Most analytic models like to assume weak selection because it allows ...
3
votes
1answer
842 views

Classification of glycosidic anomeric bonds (alpha vs. beta)

In the process of studying for my upcoming biochemistry exam, I have stumbled over the classification of glycosidic bonds. I want to be able to distinguish $\alpha$- from $\beta$-glycosidic bonds. ...
1
vote
1answer
101 views

Prothrombin time when extrinsic pathway is turned off

I was searching for an answer that "why do we need intrinsic pathway when there is fast extrinsic pathway" and i found the answer in the following link: http://www.pathologystudent.com/?p=3197 It ...
0
votes
1answer
82 views

Is “monosexual” still a valid term in biology?

I read an older article where they talk about species being strictly monosexual as opposite of being hermaphrodite, etc [1]. After an extensive googling and reading about how everybody has to be at ...
3
votes
2answers
94 views

Why are dolphins so smart?

It seems that dolphins have (among?) the highest encephalization quotients found outside of humans, higher even than chimpanzees. By the "use it or lose it" principle this indicates that intelligence ...
2
votes
4answers
153 views

Does a phenotype include the presence of a recessive gene

I am trying to understand what exactly a phenotype is to try and understand a genetics database. (Ie I don't really know very much about genetics at all) I've been reading through wikipedia on what a ...
1
vote
1answer
70 views

Botany related question: liverwort sporophyte

Is perianth part of the sporophyte or gametophyte in liverworts (Marchantiophyta)?
6
votes
2answers
2k views

Very high 260/230 absorbance ratio of an RNA sample

After my most recent RNA extraction, the RNA samples had very high 260/230 absorbance ratios, (ranging from 5 to 25). I've never gotten numbers like this and I know the ratio is supposed to be ~2 in ...
3
votes
1answer
558 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 ...
3
votes
1answer
581 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 ...
-1
votes
2answers
84 views

Could a normative population ever be non-heterosexual? [closed]

In the modern documentary called "Bi the way", one American geneticist said that if modern American youngsters may as well be functionally bisexual, then some generations ahead Americans could be ...
1
vote
1answer
171 views

Determining a patients biological age?

I am looking for an algorithm that shows the exact coefficients some variables that have on a hospital patient's chronological age versus their biological age. I understand a lot of the variables ...
2
votes
1answer
50 views

maximum # of generations possible in a population of cannibalistic rats

Assume a sufficiently large population of rats (to allow genetic variation and facilitate inbreeding) in a place with abundant water, sunlight, shelter but no food. For how many generations can this ...
-1
votes
1answer
107 views

Can pheromones in perfume be formulated to cause agitation? [closed]

I generally don't care for female perfume. I have very sensitive olfactory receptors and in general, I just find perfume overwhelming. A couple weeks ago, my wife of almost 14 years and I were ...
2
votes
1answer
74 views

How good is information transfer between the hemispheres of the brain?

I sometimes listen to lectures on my phone using ear buds, but occasionally with only one ear bud in. Is the other half of my brain losing out on any aspect of the lecture? Just how good is the corpus ...
11
votes
3answers
3k views

How long can E. coli stocks be stored at -20°C?

I'm volunteering for a biohacker lab - biocurious in Sunnyvale. The have a pretty good set of equipment - gel boxes, incubators, but they don't have a -80°C freezer yet. I'd like to set up some ...
2
votes
2answers
101 views

Is it possible to create an experiment in house conditions to prove the existence of germs?

I realise that the best way to prove the existence of germs or single-celled organisms is by looking at them through a microscope. But I don't have a microscope at my home, how can I design an ...
6
votes
3answers
6k views

What's the difference between a plant and an animal?

Are there some living things where the distinction between plant and animal is blurry or unclear? I wouldn't know where to put something like yeast. I also thought of photosynthesis, but then I ...
1
vote
2answers
137 views

Removing a restriction site and introducing other at its place

What would you do if you want to remove an EcoRI restriction site and introduce BamHI restriction site at apprx. the same location ? One of the answers in my textbook was : To construct a DNA ...

15 30 50 per page