Genetics is the branch of biology that deals with the transmission and variation of inherited characteristics, particularly chromosomes and DNA.
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Which part of a female mantises's DNA causes her to be a few times larger than a male mantis?
Which part of a female mantises's DNA causes her to be a few times larger than a male mantis?
Do other species have that part of DNA?
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3answers
1k views
Evolutionally speaking, why do humans have 46 chromosomes
In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46. Monkeys, chimpanzees, and Apes have 24 pairs (twenty-four pairs), for a total of 48.
What caused humans to have 46?
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4
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1answer
120 views
Non-monotonic knock-out effects in prokaryotes
Typically, when performing gene-knockout, the experimenters select one gene to remove/replace-with-junk and then see if the prokaryote can still undergo fission. If it continues to reproduce then the ...
7
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1answer
233 views
How many gigabytes of DNA are there on earth?
The human genome is about 770 MB, the C. elegans genome is about 100 MB, the yeast S. cerevisiae is about 12 MB. Different other genomes have been sequenced: how many GB of genomic DNA we have now?
...
4
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1answer
136 views
What phenotypes can arise from gender-related aneuploidy?
Humans normally have 46 chromosomes (two copies - one from each parent - of each of the 24 chromosomes: [1:22] + [XX or XY]).
Aneuploidy is an abnormal number of chromosomes - Down's syndromes is an ...
4
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1answer
63 views
In a vertebrate chimera, are particular organs homogenous genetically?
I have read that a chimera is an organism with two or more sets of DNA, with every cell having one of the sets. Is it possible and common for the two or more sets to be present in the cells of a ...
8
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2answers
150 views
Do twins “run in the family”?
My wife and I recently found out that we are going to have twins and so nearly everyone asks if we have a family history of twins. Now I know that the answer for me is that it doesn't matter—as ...
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3answers
325 views
Can the third sex be categorized as Male or Female?
Hijra are people who have a penis (not sure if sexually active) but look much like a female (perhaps for some feminine biological property). Wikipedia says they are "physiological males who have ...
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3answers
141 views
Why don't flies avoid the motorway?
Flies have a short lifespan, therefore evolution should technically happen over a shorter period of time (years).
Flies die all the time from getting hit by cars on the motorway.
Those flies that ...
5
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1answer
52 views
Can an organism obtaining a part of its genome via horizontal gene transfer be called a “hybrid”?
Wikipedia definition of "hybrid" offers many competing definitions. But most seem to be centered on sexual-reproduction gene transfer.
Is there an official (in a textbook or widely accepted peer ...
6
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1answer
124 views
What is Mendelian Randomization, and how is it used to infer causality in epidemiology?
Studies of human traits and diseases are inherently confined to observational studies, known as epidemiological studies. This can make it very hard to determine what actually causes a particular ...
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0answers
49 views
What is the frequency of double-hets between parent and child?
Say both parent and child are genotyped for all SNPs. In this setup we are only looking at variant positions between one parent and child - so neither parent nor child are homozygous reference (no ...
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1answer
45 views
Drosophila reference genome
Does anyone know the details about which line they are using to sequence as the Drosophila melanogaster reference genome?
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2answers
216 views
Is there any reason for the variation in mitochondrial DNA size?
As my textbook An Introduction to Genetic Analysis points out, yeast mitochondrial DNA has approximately 78 kb of genetic data, while the human mitochondrial DNA contains 17 kb. Is there any evolution ...
3
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1answer
68 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? ...
13
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1answer
208 views
Do trees age on a microscopic level?
Most animals age via at least two mechinisms:
at a "macroscopic" level, basically wear and tear to the point where (on evolutionary time scales) it's more genetically advantageous to optimize for ...
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2answers
110 views
Is there an “evolutionary species similarity calculator”?
Is there a website where I can input pairs of species and get an "evolutionary similarity score"?
E.g. (numbers are completely made up)
Input: Chimp and Human, Output: 97%
Input: Cat and Human, ...
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1answer
61 views
What's in a Name: Statistical Genetics
The novice often performs population calculations using
what is referred to as Mendelian Genetics. Soon after the
publication of Mendel's results; Hardy and Weinberg presented
their results after the ...
3
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0answers
48 views
effect of background selection on promoter regions compared to distant enhancers?
Has anyone looked at the effect of background selection on the levels of conservation of promoter regions compared to distant enhancers? Do promoter regions have a higher conservation due to ...
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2answers
399 views
Autosomal Recessive Trait when skipping one generation
I learned recently that given a pedigree it is possible to tell whether a disease is autosomal recessive by observing if the trait skips a generation. If the disease does skip a generation, then the ...
3
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1answer
48 views
What are treatable foetal conditions during pregnancy?
What are different foetal conditions during pregnancy that could be treated with appropriate prenatal genetic testing?
I only know that pregnant women are encouraged to take certain supplements to ...
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0answers
83 views
Extreme examples of protein translation/use coupling/decoupling?
What are known extreme examples of protein translation/effect coupling/decoupling? For example, examples of proteins that are immediately used at the time the have been translated and vice versa, ...
4
votes
1answer
155 views
T7 promoter leakiness
Can a gene be expressed under the T7 promoter in an E. coli strain (e.g. DH5 alpha), which does not have the T7 polymerase gene encoded in its genome? In other words, is T7 promoter leaky?
To be ...
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1answer
211 views
Are there examples of the green beard effect in humans?
Green-beard effects are genes that:
Produce an effect that can be detected
Produce preference to others with the same effect
Are there any examples of this in humans?
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4answers
512 views
Why do men have nipples?
I'd be tempted to call nipples in men vestigial, but that suggests they have no modern function. They do have a function, of course, but only in women. So why do men (and all male mammals) have them?
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8
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1answer
51 views
Relative Property of Alleles
If there are three different alleles to a gene, is it possible that the first is dominant to the second, but recessive to the third?
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1answer
135 views
What is the relative power of GWAS studies in different species?
I would like to know of any publication studying the relative power of GWAS studies in different species. For example, I've seen reports that say genotyping and GWAS in dog breeds is much more ...
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2answers
91 views
phylogenetic analysis of gene enrichment?
Are there any tools to do phylogenetic analysis of gene enrichment? This is, I have a list of genes from an experiment performed in several species, with a z-score that can be described as ...
5
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1answer
96 views
Are there any DNA base sequences that are fully conserved between the genomes of all humans?
That is, they don't differ throughout the entire population. I understand of course that we can't DNA sequence every human, so by "fully" I mean there's an incredibly small probability of there being ...
5
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1answer
116 views
Is sexual reproduction outside the same biological family possible? Ever successfully occured?
Is there an example of two species taxonomically classified in different biological families sucessfully sexually reproducing viable offspring? If not, is there an example of where reproduction ...
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votes
3answers
911 views
How does Artificial Selection work?
As far as I know for evolution to work mutations are necessary. Mutations are the raw material on which natural selection works.
But mutations are always completely random and human beings have no ...
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1answer
65 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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4answers
1k views
How many genes do we share with our mother?
Somewhere I have read we share more than 99% of our genes with every other other person and 98% of our genes with chimpanzees. What does this mean? Don't we share 50% of our genes with our mother and ...
6
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2answers
68 views
Does the word “polymorphism” refer to the gene, the phenotype, or both?
In genetics, does the word "polymorphism" properly refer to genes, to phenotypes, or both? For example, if there are two alleles that lead to differences in the structure of the D2 neuroreceptor, ...
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1answer
121 views
Are there dog breeds that are so far apart genetically that they can't produce viable offspring?
Obviously, a very large dog would have difficulties mating with a very small dog and vice versa.
But putting that problem aside (using, say, insemination), considering the large variation of dog ...
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0answers
35 views
Is there a gene that starts meiosis 2?
Yesterday I thought about a question and asked it to my friend. The question was
which gene is completely the same for a male cell that made meiosis 1 recently.
My answer was the gene that starts ...
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0answers
72 views
What is the canonical reference text for genetics terminology? [closed]
If I were looking for a reference book focused on genetics in order to look up terminology, what would be the canonical text?
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1answer
473 views
Co-transformation of plasmids from the same incompatibility group
Can two plasmids with the same origin of replication (for example pBR322 ori) and thus from the same incompatibility group be successfully co-transformed in E. coli? What are the mechanisms that would ...
11
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1answer
126 views
Have any mutations or genetic loci been associated with exceptional longevity in humans?
Individuals that avoid age-related diseases into later life are known as 'exceptional survivors', and have increased longevity compared to their 'controls' (those that were born at a similar time, yet ...
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2answers
89 views
Gametes of two different species
I always wondered why gametes from two different species dont fuse together to form an offspring. eg a donkey (sperm) and a female dog (egg)
I know this is not possible but I'm just curious.
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0answers
34 views
How many pandemic H1N1 2009 virus sequences were submitted by the Indian NIV as of May 10, 2010? [closed]
The handout I was following is maddening. It says; "Go to the NCBI home page and select 'All Resources (A-Z)' and choose GenBank. Follow the NCBI Flu Resource link to determine how many pandemic H1N1 ...
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3answers
189 views
Number of beneficial mutations cataloged?
I can see from Wikipedia that there are possibly thousands of harmful mutations that have been cataloged and linked to disease. There are also unnumbered neutral mutations. But, does anyone know how ...
5
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1answer
219 views
What generates variation in a species?
What is the biological mechanism behind the variation within sexually reproducing species? Obviously, the children are combinations, to differing degrees, of their parents. But how does the variation ...
6
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1answer
77 views
What is the effective relatedness of inbreeding?
If a human inbreeds with a relative, how distant does the relative have to be before the homozygosity in the child is no higher than if the mate were randomly chosen from the global population?
7
votes
1answer
80 views
obesity risk and single gene polymorphisms
I read a fairly recent meta-analysis of studies into the association between adult obesity and polymorphisms of the FTO gene (Peng et al., 2011). The paper looked at 59 studies and found that "FTO may ...
3
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1answer
136 views
Predicting progeny of recessive mutations using recombination
I was asked this question on a test and got it wrong, but I'd like to know how to do it. The answers are shown in the blanks below:
You are studying two recessive mutations in the fruit fly D.
...
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1answer
66 views
What exactly is meant by the expression “differentially expressed”?
As far as I've seen, this expression is almost always used in relation to gene expression profiling. Unfortunately, I have no background in this area. Can someone please explain this in layman terms?
4
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0answers
41 views
Determine which gene is in the middle complementation [duplicate]
Possible Duplicate:
Crossing mutant strains on minimal media problem
I'm studying this problem for my genetics final:
My Attempt: The answer for part B is met2 and the answer for part C ...
5
votes
1answer
296 views
The genetic and physiological origins of laughter?
This Wikipedia article defines laughter in many terms, such as...
"a visual expression of happiness, or an inward feeling of joy"
and
"a part of human behavior regulated by the brain, ...
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0answers
70 views
How to find Dmax (genetics problem) [closed]
My attempt: I'm not sure this is right but this is what i did. I found the allele frequencies to be:
A=0.4
B-0.3
a=0.1
b=0.2
I think to find Dmax I just multiply the two alleles with the larges ...
