4
votes
1answer
48 views

Where are newly discovered medicines tested

When a medicine is prepared by a biologist,then where does he first test on? And how does he know that this is the exact combination for a disease to get cured? Does he test that medicine on a human ...
1
vote
1answer
1k views

What are the differences between G+ and G- bacteria?

The distinction between Gram-positive and Gram-negative bacteria is based upon the Gram staining method, that reflects the bacterial wall physical properties. However, this classification involves ...
1
vote
1answer
56 views

Constitutive mutation in operator gene

If a constitutive mutation happens in the operator of an inducible operon, does that mean that repressors won't be able to bind them ? Or does it mean that even if repressors are bound, they will not ...
1
vote
1answer
93 views

Insect identification

It is found in my apartment in Finland. I had to kill it to stop it from getting away before looking for the camera, but it looked pretty much the same alive and intact. It's length is about half a ...
15
votes
5answers
8k views

Origin, or source, of rhesus negative in human blood

This is my first post here, so please be gentle. I recently learned that I have Rh- blood (I'm A-), and was idly looking into blood types on Wikipedia. I was surprised to find that relatively few ...
2
votes
1answer
53 views

Evolutionary conservativeness

List the following proteins in the order of decreasing evolutionary conservativeness of their primary structure: Somatotropin. Catalytic subunit of a DNA – polymerase. Histone H1. ...
3
votes
0answers
84 views

Why don't surfactants destroy or incorporate into cell membranes?

How do surfactants remain on the surface of pneumocytes without (1) acting as a detergent or (2) the phospholipids getting incorporated into the membranes of pneumocytes... I'm guessing the answer ...
0
votes
0answers
35 views

How to predict the position of the femoral head center given surface anthropometric data?

Given surface measurements such as hip breadth and hip depth, how would you predict the location of the femoral head center?
5
votes
2answers
3k 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 ...
2
votes
1answer
782 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
67 views

Mites on ginger root

I was just looking at some mouldy ginger found in the fridge under the microscope and was horrified/delighted to find (what looked to be) mites growing in it. I have searched the web and can only find ...
1
vote
1answer
70 views

Why do peas change colour?

I am doing an experiment on preservation of peas. The first notable change to the peas over a period of one week is that they have changed colour from bright green to a dull colour... Why is this ...
1
vote
0answers
16 views

Phylogentic Footprinting Project

I'm working on performing phylogentic footprinting to figure out how many TRE sequences there are in the TWIST1 gene. (Sequence motifs). I'm trying to use ENSEMBL to gather orthologues of species in ...
1
vote
1answer
211 views

Genetic Epistasis Question

I need help with this practice question. I'm assuming that would a epsitatic recessive question since the parents are true breeding and then the ratio would be 9.3.4. But I am not so sure. Any ...
1
vote
1answer
112 views

Pedigree Diagram help

I am asked to fill the genotypes in the spaces provided but looks like I am aving a little bit of trouble. can anyone help? thanks in advance!
0
votes
1answer
121 views

PedigreeAnalysis Genetics [duplicate]

Hello! I need help with this exercise question. I am not really sure which pedigree diagram is autosomal and which is not. But, is question b 1/2. Can someone give an explanation? Thanks very much ...
4
votes
1answer
54 views

Where can I find histograms and tables of prevalence of mutations in cancer?

At some point in the past I found a cancer portal site which had aggregated data for the relationships between various mutations and their prevalence in cancer types and tumor data. The data was ...
5
votes
2answers
94 views

How extensive is CD47?

CD47 aka the "don't eat me" signal has recently been claimed to be expressed on all tumor cells. This doesn't seem to corroborate with other cell-biology experiments. On what other cells is CD47 ...
2
votes
1answer
51 views

Need help distinguishing between a primary and secondary source

I am trying to figure out if the following article is a primary or secondary source. I'm leaning towards secondary but here are my cases for both. Primary: Published in a peer-reviewed ...
1
vote
1answer
35 views

Why all particles have same influence on osmosis

When people talk about osmosis, they say that when we add a mole of NaCl, then each its molecule gets dissolved into 2 separate particles and therefore we have 2osM/L solution. But both Na & Cl ...
3
votes
1answer
102 views

Why is Turner syndrome rarer than Klinefelter syndrome?

Turner syndrome occurs in 1-1000 to 1-5000 females, and Klinefelter syndrome occurs in 1-500 to 1-1000 males. Why is Turner so rare even though they both are caused basically by the same mechanism?
2
votes
0answers
27 views

Are human infants inherently frightened by anything?

Naïve question - feel free to shoot it down. To the best of my knowledge an infant doesn't really 'shrink' from something without first trying it. Even the action of looking at the fierce expression ...
1
vote
1answer
56 views

Molting in arthropods

Do all the arthropods molt ? Which ones do not molt ? Why don't they need to molt ? I tried googling this - but did not get satisfactory answers.
2
votes
1answer
85 views

What is this image?

What I understand is- I think this is picture of DNA. But why is it in this conformation ? What types of cells have this type of DNA ?
2
votes
1answer
55 views

Determining whether X chromosome from sperm or egg

Is there any way of determining which X chromosome a female inherited from her father and which from her mom ?
5
votes
2answers
124 views

Can you tell the sex of a white willow when it's not flowering?

Can you tell whether a salix alba tree will produce male flowers or female flowers by looking at it, touching it or generally using your unaided senses? If not, is there any way to do that without ...
0
votes
1answer
56 views

probability of having normal daughter

If father has hemophilia, mother is a carrier of the disease, then what is the probability of having a normal daughter ? My question: Should the probability of having a daughter be also ...
4
votes
1answer
43 views

What are the molecular mechanisms that make the turtle brain more resistant to hypoxia?

I know that turtle brains, particularly those of individual species that hibernate and burrow are particularly resilient to hypoxia and any tissue damage secondary to a hypoxic event. What are the ...
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 ...
1
vote
0answers
20 views

Are sulfates or nitrates common ions in biochemistry (specifically of the body)?

It's a rather broad question but something I'm curious about. I know sulfates tend to be very soluble ions and so don't know nitrates. I also know that phosphates are extremely common in ...
4
votes
2answers
104 views

Reference sequence for defining single nucleotide polymorphisms

Single nucleotide polymorphism (SNP) or genetic variation in general, by definition are relative to a reference sequence. When we talk about databases of SNP as in ("dbSNP—Database for Single ...
2
votes
2answers
176 views

Are there enzymes found in nature or the man made world that can help break down metals?

The title says it all. Do natural or human engineered enzymes exist that can speed up the break down kitchen utensils, aluminum cans, wires, etc. into small particles or powders? To be clear I am ...
1
vote
1answer
40 views

Vesicular and non vesicular transport

I have to classify them either as transported in vesicles or without vesicles. What I think - Non-vesicular 2.vesicular 3.vesicular 4.vesicular 5.non-vesicular 6.vesicular 7.vesicular ...
0
votes
2answers
93 views

What is “transcribed strand”

This is an excerpt from a paper: T>C mutations at NpTpN trinucleotides, also found in hepatocellular carcinomas, shows strong transcriptional strand bias with more T>C mutations on the transcribed ...
-1
votes
2answers
442 views

How did fish evolve the ability to breathe on land?

Doesn't make sense. It would be like a human evolving the ability to breathe on the moon without a spacesuit. How would the organism be able to carry out such an evolutionary adaptation, when the ...
2
votes
1answer
105 views

DNA ligase mechanism

I am unable to understand what happens to the phosphates from ATP. What are they used for ?Charging 3' end or 5'end ?
0
votes
1answer
1k views

What happens to our body when we undergo a sudden temperature change?

We know that a glass gets cracked when it undergoes sudden change in temperature. But what will happen in the case of a human body if it changes from the maximum(>35 C) to the minimum ...
1
vote
1answer
131 views

Breathing in and out

I was reading my textbook and it says that breathing involves inhaling and exhaling but it doesn't say whether they happen simultaneously or sequentially. Also is my overall understanding of ...
0
votes
1answer
282 views

SNP genotyping using PCR

I read this wikipedia article on SNP genotyping and wasn't able to understand this part : In examining the results, if a genomic sample is homozygous, then the PCR products that result will be ...
6
votes
1answer
752 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 ...
1
vote
2answers
579 views

Gel electrophoresis after RNAse treatment

I do not understand how to solve this question. I know that RNAse will cut smaller pieces of RNA. The answer given is A
7
votes
3answers
195 views

How should I put a large phylogeny into a scientific paper?

I've been trying to put a phylogeny tree into a scientific paper. This tree includes ~220 species, which is too too large for one page for journal articles (Letter or A4 size). But in my paper it is ...
2
votes
1answer
69 views

Physiological reason why leaves got twisted when treated with indole acetic acid

I want to know the physiological reasons of why the leaves of my study plant got twisted when treated for 10 days with spray of indole acetic acid. I want to treat seeds with IAA, and I'm thinking ...
2
votes
1answer
284 views

How can Southern blotting be used to establish gene copy number?

I am reading a paper on a certain marine microorganism that can eat alkanes and therefore might be useful for cleaning up oil spills, etc. This sentence struck me as odd (although I am sure that the ...
3
votes
1answer
36 views

Which part of oranges contain fiber?

I think it's pith, but here (non-english country) many chef suggest orange's vascular veins which look "fibrous" and have similar translated word with "fiber" itself. Please enlighten me which?
2
votes
1answer
63 views

Where to obtain metabolic pathway datasets

I've been looking through the files available at www.reactome.org along with some others but I only find images/pdfs of metabolic pathway diagrams. Where is the actual data these pathways are drawn ...
0
votes
1answer
25 views

Different level of toxicity between smoke

Has there been studies on the difference between the smoke generated from: cigarette or cigar manufactured by brands which are proven to contain more than a hundred of dangerous additional ...
2
votes
1answer
67 views

Can cerebrospinal fluid deliver nutrients/drugs to neurons during sleep?

I'm looking at this article on the possible mechanism of detoxifying brain during sleep using cerebrospinal fluid. It states that at night, the space between neurons may allow better (up to 20x) ...
1
vote
1answer
65 views

How suddenly does lactose-intolerance onset?

How quickly can the loss of lactose tolerance onset in an adult? Such as being able to process lactose normally to having notice symptoms associated with the inability to process lactose. I am not ...
1
vote
0answers
27 views

Systematic anticoagulant injection after a CVA

Since most of the cerebrovascular accident are ischemic ones, would it be usefull to have anticoagulant everywhere (we already have AEDs everywhere) so that everytime someone would have symptoms of a ...

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