All Questions
302
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What is a reference strain in DNA-DNA hybridization DNA groups?
Results
DNA groups identified:
All intra-group relatedness values are shown in
Table I.
By means of reference strains, most of the DNA groups could be identified as groups described by Bouvet & ...
- 343
1
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2
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40
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Preserving a sample for mtDNA and nuclear DNA analysis
Imagine a person in the early half of the 20th century (1900 to 1950) took some kind of sample(s) from a living human body using any technology of the era. They then stored it using any technology ...
- 141
3
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2
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158
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Change of DNA concentration due to restriction digest?
Assume that you perform a restriction digest in a molecular biology lab: you combine genomic DNA, a restriction endonuclease (e.g., EcoRI), and the optimal buffer for that endonuclease and are about ...
3
votes
1
answer
135
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Can a person have different sex at cellular level?
I mean like every cell has a sex chromosome.So does a male with XY chromosomes has all the cells in all the organs inside his body of XY chromosomes only? And vice versa.....
- 39
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2
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104
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How many base codes are in DNA? Two or four?
We know there are four bases found in a DNA: adenine (A), cytosine (C), guanine (G), and thymine (T). We also know that A always pairs with T and G always pairs with C. Can we say that the DNA is ...
- 101
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20
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Ames Assay Confusion: Aren't the odds of spontaneous revertants too low to be able to accurately test the mutagenicity of certain compounds?
I am a student conducting a test with the Ames Assay. This assay uses a strain of bacteria that has a mutation in an amino acid synthesizing operon, which doesn't allow it to synthesize its protein. ...
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1
answer
52
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Inheritance of child behavior based on daily life experiences of the parent
Our brain is a large network of neurons connected with each other.Our daily experiences change how our neurons are connected.Some experiences create better connections between two neurons A and B and ...
- 101
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1
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157
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Calculating pitch of B-DNA
From this question (How pitch of a DNA Helix is 3.4 nm?), I've learnt that for counting the number of axial rise for 10 base pairs in 1 helical turn to measure the pitch of B-DNA, we have to include ...
- 23
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182
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What do alleles look like visually on linear DNA strands?
I've seen many textbook images of alleles on homologous chromosomes with the gene loci identified but how could this be visualised on linear DNA sequences with the bases written out? Is it that you ...
1
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1
answer
43
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ddT-tailed TA cloning, and the fate of a double nicked plasmid in E. coli
In an undergraduate lab class on TA cloning, it was explained that ddNTPs are used as the substrate for terminal transferase when making the T overhangs of the vector. I was told this was to ensure ...
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337
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How pitch of a DNA Helix is 3.4 nm?
How pitch of a DNA Helix is 3.4 nm?
In the image that I have attached, the numbers with prime represent the number of base pair and normal numbers represent the number of gap elements between two base ...
- 121
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1
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89
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How do we know that the DNA we share with other species (especially primates) isn't fully the result of transposable elements?
I recently read a couple studies that concluded the 25% of genetic similarity between cows and reptiles is actually primarily due to TEs (transposable elements) rather than common ancestry.
Here's the ...
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0
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17
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Are there limitations in using DNase I hypersensitive sites (DHSs) to identify candidate enhancers?
Candidate enhancer regions are often defined in studies by DHSs and/or certain chromatin marks. I was wondering if DHSs are exhaustive for identifying possible enhancer regions, and if there is any ...
- 11
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2
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119
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Can gene mutations cause Down's syndrome in humans?
I am working on an A levels questions:
Which of the following statements about gene mutation is incorrect?
A. It can occur in both somatic and sex cells
B. It can cause Down's syndrome in humans
C. ...
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63
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Are gene conversions and expansion/contraction of repetitive (satellite) DNA examples of directional, non-random mutations?
Are gene conversions and expansion/contraction of repetitive (satellite) DNA examples of directional, non-random mutations? For some context, it was brought to mind as a result of reading the ...
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