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11

The short summary is that typical TFs bind and read both strands together, as a basepair sequence. Some proteins instead recognise a site on the helix by its shape and flexibility. ssDNA-binding proteins obviously bind one strand but they do this in a non-specific manner. RNA-binding proteins recognise the sequence on a single strand by inserting ...


8

Yes, these sequences exist and they are called "silencers" (surprising, right?). There are different mechanisms by which this silencing of genes can happen. In the "classical" way the silencer is bound by a transcription factor which either passively suppress the gene by hindering the binding of specific transcription factors or by actively preventing the ...


6

This is a great question. Just to make it clear people with DS do have a reduced risk of solid cancers and an increased risk of blood cancers, (B-ALL and AML). You are correct in picking out DSRC1 because of its angiogenic implications. The current hypothesis centers around people with DS being less capable of driving angiogenesis, and therefore having an ...


5

High-throughput, as indicated by canadianer in their comments refers to amount of data that is processed by the system. Though the answer by CactusWoman would be correct for the case of DNA sequencing, high-throughput is not really confined to that domain. Any high-throughput technique tries to measure several variables simultaneously. The examples include, ...


5

They are not chosen, they represent an even half, a complete set of chromosomes. The entirity of a cells genes (found on the chromosomes) is called a genome. Somatic cells are the cells in our bodies that exclude sperm and egg. Sperm and egg are called germline cells. The billions of somatic cells in a homo sapien have the same 46 chromosomes. 23 ( ...


5

Parent 1 and 2 have each 5 possible genotypes (OO, AO, BB, BO and AB). Here a Punnett square with each possibilities. I highlighted the possible parent genotypes. The total number of possible crosses is exactly 21. Note that here A = Ia, B = Ib and O = i. OOxBB,OOxBO,OOxAB AOxBB,AOxBO,AOxAB BBxOO,BBxAO,BBxBB,BBxBO,BBxAB BOxOO,BOxBB,BOxAO,BOxBO,BOxAB ...


4

Positive feedbacks can be one alternative. Positive feedbacks exhibit bistability and can therefore adopt one of the two stable states depending on the initial condition. A famous example of a positive feedback switch would be that between cI and Cro in λ-phage, which repress each other. Positive feedbacks also display hysteresis: if the state of the system ...


4

Claudia's dad is not a taster, so he is tt. He passes one allele on to his daughter. Since he is homozygous, he can only pass t. Claudia is a taster, so she must have the dominant allele from her mother, who is also a taster. Thus, Claudia is Tt.


4

Dyad is the centre of the DNA that is wrapped around the nucleosome core (It basically is the centre of symmetry of the nucleosome). It is a common practice to set it at 0 thereby making incoming DNA half, negative and outgoing DNA half, positive. By oscillations the authors mean that there is a periodic repeat of A/T dinucleotide. IMO it is actually not ...


4

Even though you - or the problem did not clarify, I assume in my answer that you work with eukaryote system, even though the principle of the replication is the same. dNTPs do have an OH group on their 3rd carbon atom (for eg. check this wiki-page for dCTP) so I don't think that's the issue here. My guess is that the first tube contains the radio labeled ...


4

Short answer: Yes, you can. Usually these are coupled systems for transcription and translation. For these you clone the gene of interest into a vector which contains a prokaryotic promoter which is then used to generate the mRNA in the tube. This mRNA is then translated in the second step into a protein. This works very well, but the protein is missing ...


4

First of all, the $\mu$ is not expected time for a mutation to occur and get fixed; it is the rate at which mutations are fixed in the population. The basic result states that if neutral mutations arise at a locus at rate $\mu$ within individuals, mutations at this locus will be fixed in the population at rate $\mu$ as well. The expected time for a given ...


4

This question can't be answered with a simple yes/no, but I would say that the analogy of DNA being the "code" used by cells is a reasonable one, if taken with a number of other considerations. DNA function When Watson and Crick first described the structure of DNA (being a double-stranded sequence of the nucleotides Adenine, Cytosine, Guanine and ...


4

The evolution of self-fertile hermaphrodites is thought to be a specialization that occurred several times in the nematoda. For example, most of small, free-living soil nematode species related to C. elegans are male/female. C. briggsae, which last shared a common ancestor 80 myr ago is also male/hermaphrodite, but I believe their ancestor is thought to have ...


3

High-throughput sequencing specifically refers to sequencing techniques like Illumina that allow you to sequence massive amounts of DNA at once (hundreds of thousands of strands), as opposed to older techniques such as cloning the cDNA in plasmids, followed by sequencing.


3

I think you are misunderstanding "color" here. When applied to cats, it doesn't literally mean a color shade as used in color theory, but "coat color" which can in fact also be a "coat pattern". The cats above are two-colored, not three-colored. One color is white. The other color is what is called "tabby" in English and is a pattern of dark spots arranged ...


2

Short answer, in theory yes, in reality, at the current state of the art, no. I guess you are speaking about higher organisms (such as mice or humans), if you are referring to small non-complex multicellular organisms then the answer is yes as far as you can transfect every cells with the system described hereafter. The most promising technique is using ...


2

EDIT: Short answer : Yes: "allele" is a synonym for "gene variant", irrespective of location (locus). Background Original answer: From About Education I found this definition for an allele: An allele is an alternative form of a gene (one member of a pair) that is located at a specific position on a specific chromosome. EDIT: Hence, two alleles are ...


2

Okay so in your teachers answer there are four offsprings. . You used all offsprings when you made the division so 2/4 = 1/2.Your teachers 2/3 comes from the fact that 3 out of four is black, but only 2 out of that 3 black is heterozygote so 2/3 is good by this logic. I think that your teacher's logic faulty because you have to take into consideration all ...


2

Genome wide functional linkages refers to protein in a biochemical or signalling pathway. Inferences of functional interactions can be obtained from methods such as coexpression data from microarray analysis. Since experimental detection of genome-wide protein–protein interactions is costly and time-consuming a computational scope for essentially predictive ...


2

Addition to the answer provided by Teige. Transcription factors bind to both the strands however your question also included proteins in general. DNA remains double stranded and twisted as helix most of the times; most proteins bind to both the strands as mentioned in the previous answer. However some proteins such as SSB (Single-strand binding protein) ...


2

There are definitely genomic DNA sequences that nucleosomes preferentially package in vitro. They are A/T rich and have a periodic structure that facilitates bending. However such sequences would typically not be found on exons in vivo (because their protein-coding potential is reduced). Based on the accumulating literature, active promoters (and regions ...


2

Transcription interference can also be a good mechanism to provide such switches. Transcription interference occurs between genes in close adjacency to each other. This is basically, as the term suggest, that the neighbouring genes can interfere with each others transcription (by overlapping promoters blocking transcription initiation, collision of ...


1

Conjugation occurs between cells of the same species too. For this to occur cell have to be close to each other. Now, if you have an isolated population of bacteria that never gets in contact with an F+ bacteria then this population would stay F-. Also not all conjugation events are successful, mechanical perturbations can disrupt the pilus through which ...


1

To support mdperry's answer: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2429870/ Figure 2 in particular should draw your attention as it shows the previously mentioned correlation between chromosome size, transcripts and embryonic viability. Apologies, I would have added this in comment form but I do not have enough reputation.


1

According to the "Functional adaptation" section of this webpage, Deinococcus radiodurans uses repair proteins to stitch up DNA after radiation damage. Meaning, after a burst of radiation, the DNA will be in pieces and the repair proteins put it back together. It seems like this mechanism would not come into play during other forms of DNA mutation that ...


1

For 5' extensions or blunt ends, incubate the sample for 15 minutes at 37 degrees Celsius. For 3' extensions, incubate the sample for an hour. https://www.neb.com/protocols/1/01/01/vector-dephosphorylation-protocol


1

"Cloning a gene" also just means making tons of copies of it, like in PCR, so you can sequence it


1

You are on the right track, but you have to keep in mind there are multiple ways to have two dark and one child in a group of three. You have to add the probabilities of each unique outcome that results in two dark and one light child. So, the probability is (1/4) x (3/4) x (3/4) PLUS (3/4) x (1/4) x (3/4) PLUS (3/4) x (3/4) x (1/4)



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