Genetics is the branch of biology that deals with the transmission and variation of inherited characteristics.

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Why aren't introns found on the ends of pre-RNA?

We recently learned in genetics class that exons always cap the ends of nascent RNA. I have been trying to figure out the reason why introns can't instead be found on the ends instead of exons. The ...
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151 views

Why do we use DNA sequencing methods such as shotgun?

I am learning about DNA cloning for the first time. What I understand is that, in order to clone DNA, we break-up the original gene into shreds. Then try to piece it back together. Why exactly do we ...
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49 views

Heterochromatin production limitations

Currently playing with some ideas for a project and needed some guidance. I am wondering, both in Drosophila melanogaster and in general, is the amount of heterochromatin a cell/nucleus can produce ...
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2k views

What is the purpose of back-crossing mice for multiple generations?

Occasionally I will come across articles that refer to back-crossing mice of one strain onto the background other another strain (e.g., C57Bl6). They do not explicitly state the purpose for doing so, ...
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69 views

Mode of inheritance - DYT1 Dystonia

Homozygous DYT1 mutation carriers have not been reported in humans. Does this mean that the mode of inheritance for dystonia (DYT1) is autosomal dominant? This to me implies that if one has both ...
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3k views

What is the standing genetic variation?

I am reading this review. In the first part, the author introduces Standing Genetic Variation, described as: STANDING GENETIC VARIATION Allelic variation that is currently segregating within a ...
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128 views

Publicly available genotype data?

I am a statistician and I'd like to test my new method on biological data. For this I am looking for genotype data for a number of individuals. That is, I am looking for something like this: ...
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3k views

What is the genetic basis of blood type (ABO) system?

What is the genetic basis of the A/B/B+/O/etc. blood type system? Are there definitive loci that correspond to each or can multiple different genotypes produce the same antigen profile? Also, is the ...
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1answer
3k views

Difference between viral and human genetic material

I have heard that there is a difference between viral and human genetic material. What is that difference? If I take my cells and take DNA out of them and insert only a small part of it having a ...
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2k views

Knockdown of long noncoding RNA (lncRNA) - how is it done?

I don't work at the wet lab and don't know all the details about the knockdown techniques. My question is: How lncRNA knockdown is done? For example - you have lncRNA that is functional in the nucleus....
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1k views

What is an epistasis group?

I have been trying to wrap my head around the concept of epistasis for a couple of days now, and I think I understand it, at least at a basic level, but I still don't understand some of the ways that ...
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86 views

What accounts for size variation in breeds of dogs?

My assumption is that dogs vary so much in size because of artificial selection pressures coming from human breeders, but are there genetic loci that roughly determine approximate size? Do other ...
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113 views

What are Haplogroups?

What exactly does the term Haplogroup or Haplotype means? How is it claimed that people belonging to the same haplogroups have common ancestors?
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47 views

What are the exceptions of Mendel's laws?

What are the exceptions of $-$ Law of dominance Law of independent assortment Law of segregation My knowledge: Exception of law of dominance: Incomplete dominance: Unlike dominance in ...
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38 views

What is heteroduplex?

I fail to understand the what exactly is heteroduplex due to unavailability of a suitable diagram. According to wikipidea: A heteroduplex is a double-stranded (duplex) molecule of nucleic acid ...
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77 views

How Much DNA do Siblings whose Parents are First Cousins Share?

On average, two siblings generally share 50% of their genome. How much does this increase if the siblings' parents are first cousins?
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85 views

How likely is it that a person's progeny has an inheritable disorder based on this pedigree?

Case study: A person (let's just call him "John") had 3 aunts that died back in the 1950's in early childhood due to an unknown form of neuromuscular disorder. One died at birth, one at 2 years and ...
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62 views

Mutating a protein without mutating the gene?

Is it possible to mutate a region of a protein (says about 300 amino acids long) without actually mutating the gene? One possible way that I can think of is to use RNAi and specifically block that ...
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41 views

DNA replication : binding

Regarding an activator, does the C amp cap complex, bind to the coding strand, the template strand, or both?
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60 views

Does DNA polymerase I require a $3^\prime$ end?

DNA polymerase III adds nucleotides in the $5^\prime \rightarrow 3^\prime$ direction because it can only add nucleotides to the $3^\prime$ end of the previous nucleotide. This is why it requires a ...
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112 views

What does the “*” in haplogroup I2A1* mean?

I have been told that the "asterisk" in the Haplogroup 12A1* means it doesn't move down stream? What exactly does that mean in layman's terms?
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153 views

How do eukaryotes terminate transcription? (clarification on Campbell Biology)

I'm having trouble understanding how eukaryotes terminate transcription. Studying Campbell Biology (pg. 342, 10th ed.), I read: In eukaryotes, RNA polymerase II transcribes the polyadenylation ...
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251 views

How does Cro protein expressed by lambda phage kill its host?

I read that the DNA segment of lambda phage integrated in host DNA could switch between lysogenic state where cI represses the expression of Cro and lytic state where Cro expression takes over and ...
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76 views

Write the haplotypes of the family

I'm doing old exam assignments to prepare for my finals on Monday and I've stumbled on one assignment that I'm not sure how to tackle. A family with 2 children is examined for cataracts using PCR ...
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62 views

Terminology for inefficacy of selection on recessive alleles

I am wondering is there some proper terminology which is used to say that deleterious recessive alleles might be able to hide, reducing the the efficacy of selection, in diploid organisms/chromosomes. ...
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49 views

Obvious phenotypic inheritance markers in humans

In humans, are there phenotypic markers that prove parenthood? For example, if mother and father have <trait characteristic> (let's say, specific ear lobe ...
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927 views

After how many generations descendant is not more related to ancestor, than to a random individual in an ancestral population?

Descendant of n generation has on average 1/2n DNA of ancestor. (For example children have 1/2 DNA of parents and 1/4 DNA of Grandparents, After 10 Generation 1/1024 DNA and after 100 Generations 1/...
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340 views

Which is better against genetic mutations? Asexual or Sexual Reproduction?

In terms of genetics, which type of reproduction is better against adverse mutations? I understand a bit of Muller's Ratchet—in which asexual organisms accumulate a number of deleterious mutations in ...
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254 views

What is the difference between a DPY-10, DPY-11, and DPY-13?

My TA mentioned these three mutations of C. elegans since we started working with the worms but seems to skip over what the differences are...
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183 views

Are people genetically predisposed to being interested in specific fields/ideas? How does specialization occur?

I'm not sure if I formulated my question well, but I'm curious about a couple statements made by Steven Pinker and and James Heckman. In this interview: http://www.youtube.com/watch?v=KJ9Ad6s8g7I&...
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100 views

Heterozygosity under genetic drift

The wright-Fisher model of genetic drift is: $$p_{ij} = \binom{2N}{j}\left(\frac{i}{2N}\right)^j \left(1- \frac{i}{2N}\right)^{2N-j} $$ ,where $\binom{2N}{j}$ is a binomial coefficient. From this ...
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92 views

How do mosquitoes maintain telomere length?

While the vast majority of eukaryotic organisms maintain their chromosome ends (telomeres) via telomerase, an enzyme system that generates short, tandem repeats on the ends of chromosomes, other ...
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465 views

Possible Genotypes of 4 Alleles of Adh

There are four alleles of Adh which are Adh-1, Adh-2, Adh-3 and Adh-4. Their respective frequencies are 0.11, 0.84, 0.01 and 0.04. What are the Hardy-Weinberg frequencies of the possible 10 ...
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72 views

How diverse are dogs in their traits other than appearance?

I've asked this question about dogs not so long ago, and the short answer was - dogs are the most diverse looking species of mammals because they got a small number of genes that have a big impact on ...
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189 views

Chromatin shearing: what is it and what are the effects of high-sensitivity?

I am reading a paper which discusses a complex (MSL-DCC) involved in dosage compensation of the drosophila X-chromosome. Descriptions of the complex's structure and function are given in the papers ...
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681 views

Transcription factor binding site located in intron

I have noticed that some TF binding sites are located in the introns of the genes. I am puzzled about whether the TF only binds to DNA in the initiation stage of transcription and will detach during ...
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4answers
199 views

How did the activities of protocells become inheritable?

I have learned that first a protocell came to exist and its characteristics came to be passed on by genetic material. So how come genes for all the activities come to incorporate into genetic material?...
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104 views

Low complexity region and relaxed selection

I'm reading a text (Wagner, 2007) on identifying positive selection. In paper, the author says that low complexity regions are known to be associated with relaxed selection. I'm trying to understand ...
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556 views

What factors govern the variable age of onset in Huntington's Disease?

"Huntington's disease (HD) is a neurodegenerative genetic disorder that affects muscle coordination and leads to cognitive decline and psychiatric problems." As we all know, this genetic disease ...
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78 views

Historical recovery from mass extinction events

Is there a way to generally characterize how species "regrew" after the various mass extinction events happening periodically from 450 Ma to 65 Ma. Would the surviving species just start back where ...
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30 views

Mutation in axillary buds of trees overcoming self-incompatability?

I seem to recall from either reading or lecture that there have been instances of trees that are self-incompatible accumulating enough mutations in an axillary bud that the resulting branch was able ...
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92 views

Predictable microchimerism

I read in New Scientist recently that microchimerism occurs between previously born siblings and grandparents, not just the mother. Do we know which parts of the genome are likely to be transferred? ...
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86 views

Pink Grasshoppers

The area I found this grasshopper was Canyon Country, California, USA In a desert/field area. I have been reading up on grasshoppers because I recently came into possession of a pink grasshopper (It ...
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31 views

Gemini usage of --sample-filter

I am using gemini to query databases made from vcf files, which contain data from multiple samples. However, I need to query data only from one sample, (for which I currently use grep to filter the ...
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235 views

Are gametes determined by the sex of an organism?

In the Wikipedia article for biological sex, I read the following sentence. "The gametes produced by an organism are determined by its sex:..." However, is it not through the gametes produced by ...
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81 views

How C. Elegans is used for siliencing genes

The experiment that is using C. Elegans to silence the Genes. I have a question about Why and how C. Elegans can use the DNA plasmid that is generated with the gene of interest in the bacteria by ...
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95 views

How could one calculate the gene flow between two populations?

Imagine there are two populations X and Y, and for each population you have the genotypes of each individual in that population (e.g. Aa, AA, aa, etc.), but for multiple loci (e.g. AABb). How could ...
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1answer
32 views

Fruit Fly Hybrids

I have a food waste bin in which I put fruit scraps. The fruits come from all over the world, mainly Europe though. I'm in the UK. I assume the fruit Fly eggs are already in the fruit, in which ...
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45 views

Quantitative Trait Locus process?

I do not seem to understand the concept of Quantitative Trait Loci(QTL's), can anyone explain it to me in detail? Reading the wikipedia article helped somewhat, but I do not understand it well. What ...
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Forensic genetics- why is mtDNA comparison sometimes better than nDNA comparison?

Why is (in forensic genetics) in some cases more appropriate comparison of nuclear DNA but in some other cases comparison of mitochondrial DNA? Is it because geneticists are sometimes unable to find ...