A single piece of DNA coiled and organized along with RNA and proteins found in the cell.

learn more… | top users | synonyms

3
votes
0answers
20 views

What would the resulting karyotype be if someone with Klinefelter syndrome fertilized an “empty” egg?

Endoreduplication: is a form of nuclear polyploidization that results in multiple, uniform copies of chromosomes. This process is common in plants and animals, especially in tissues with high ...
2
votes
1answer
945 views

recombination frequency problem

Three loci C, D and E are located on the same chromosome in this order. We found that the frequency of recombinants between C and D is 10% and that between D and E it is 20%. Assuming that ...
2
votes
2answers
148 views

Is it more likely that the very first living organisms had a linear genome?

Is it right to assume that the first living organisms on earth had a linear genome? I base this on the fact that linear macromolecules are clearly much more common in nature that circular ones. To be ...
2
votes
1answer
154 views

Which of the two chromosomes in a pair is expressed?

I have completely dummy question. I have 23 pairs of chromosomes in the cells 23 single coming from my mother and 23 single from my father. So how my cell choose which chromosome, mother's or ...
2
votes
1answer
118 views

From a computer science perspective, how is DNA compared for various purposes?

I am very interested in privacy preserving technolgies, such as Microsoft PINQ and would like to see if this is applicable to DNA comparison. Given that I don't have a background in biology, I ...
2
votes
1answer
507 views

What is the result of meiosis?

Is the result of meiosis ONLY the sex gametes (male and female) which later meet to form a somatic cell? Sometimes I feel as if my book is hinting towards meiosis is the process where sperm cells meet ...
2
votes
2answers
1k views

How many recombination events are there per generation in humans?

I'm looking for a reference that tells me how many recombenation events occur in humans from one generation to the next. Assuming that the human genome is a 3.3 GigaBases long DNA sequence, how many ...
2
votes
1answer
321 views

What does chromosome CHR_Un, CHR_MT in the ftp site of NCBI mean?

I am not a biologist. But need some genetic data. So I searched internet and reached NCBI's website. I came to know from the FAQ page that I can the complete genome data of organisms from ...
2
votes
1answer
564 views

What is the structure and function of chromosomes during interphase?

Ok, it seems to be easy but I have probably ignored something by accident. Interphase is the phase where things are growing and the preparation for cell division happens. Its stages G1, S and G2. DNA ...
2
votes
1answer
61 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 ?
2
votes
1answer
242 views

What's the difference between a free chromosome fragment and an extrachromosomal array?

This is reference to a review on C. elegans mosaic analysis by Yochem and Herman, in which the authors make a distinction between free chromosome fragments and extrachromosomal arrays. For the ...
2
votes
2answers
139 views

Can a new Y-chromosome be created?

The major gene of the Y-chromosome is SRY. Would it be possible to get the X-chromosome and add SRY to create a "fuller" Y-chromosome? What advantage does the skinny Y-chromosome give an individual ...
2
votes
2answers
39 views

What is the length of the centromeric repeat sequence in a human?

I'm looking for the lengths of the centromeres of human chromosomes. The best I could come up with so far has been: The length of individual centromeric arrays was found to range from an average of ...
2
votes
1answer
2k views

Properties of Satellite Chromosomes

I have some questions regarding Satellite chromsomes which could not be resolved by a google search. Does the satellite consist of telomeric sequences ? If not, What is the function of a satellite ? ...
2
votes
1answer
61 views

How are new chromosomes replicated into the next generation via sexual reproduction?

If an individual has a new chromosome, which is very unlikely to happen, he will not have any luck in finding a sexual partner with this same trait. How will the offspring inherit this trait. And ...
2
votes
2answers
80 views

Maintaining purebred pedigrees and how to lessen chance of getting disease?

Many breeds of dogs are known for a high incidence of genetic disorders. German shepherd and Saint Bernard dogs are predisposed to developing a crippling condition called hip dysplasia. Q: What ...
2
votes
1answer
96 views

Have there been any experiments that duplicate chromosome copies from 23*2 to 23*3 or 23*4?

Deinococcus radiodurans is an amazing bacterium with a fantastic survival rate. It can survive to high doses of radiation, in a complete vacuum and in hydrochloric acid. How does this bacterium ...
2
votes
0answers
35 views

Why are published chromosome counts for polyploids often incorrect by an integer multiplication factor of the original diploid like count?

Why are published chromosome counts (done using techniques such as root smashes) for polyploidy flowering plants often incorrect by a multiplication factor of 2 or 3 from the original diploid like ...
2
votes
0answers
40 views

How much difference in genome is enough to prevent interbreeding? [closed]

I am not a biologist. I am a software developer interested in genetic algorithms therefore i am probably talking to biologists who also have a knowledge of genetic algorithms. I need to "breed" ...
2
votes
0answers
38 views

examples of chromosomal aberrations with lack of sexual chromosomes?

Are there any examples in animals where individuals survive having no copies of their sexual chromosomes?
2
votes
0answers
40 views

Example(s) of reduced rate of mitotic progression?

Most species complete mitosis, and in particular the process of chromosome condensation, rather quickly, in a matter of minutes. Are there any known species that undergo mitoses with substantially ...
2
votes
0answers
117 views

Are there any mammals in which polyspermy produces viable zygotes?

Are there any mammals in which polyspermy produces viable zygotes? In the wikipedia page it is mentioned that there is a delicate equilibrium between female defenses against many sperms, which ...
1
vote
1answer
792 views

How are 23 chromosomes in human sperm chosen?

I'm not biologist and I have just a basic knowledge. I've been thinking for a long time about the following question: How does the body choose which 23 chromosomes should be active in human sperm and ...
1
vote
1answer
887 views

What is the advantage of circular genomes for bacteria and linear genomes for other organisms?

Bacterial are a great group of organisms. They have circular genomes and never went toward linear genomes while other organisms show the opposite strategy and don't have circular genomes (disregarding ...
1
vote
3answers
89 views

Whole Genome Sequencing and Chromosome Counts

In general, do standard whole genome sequencing techniques rely more on known chromosome counts, independently arrive at chromosome counts, and/or not directly address issues such as base number, ...
1
vote
1answer
102 views

Can IVF decrease the probability of trisomy in the fetuses of older mothers?

Is trisomy mostly due to complications with fertilization? If so, does in vitro fertilization reduce the probability of trisomy for the fetuses of older mothers? If not, can zygotes be screened ...
1
vote
1answer
360 views

Would two species of yeast with similar genome sizes have the same number of genes or chromosomes?

Similar organisms generally have similar genome sizes. Given this, would two species of yeast have the same number of genes and chromosomes? Edit: Fixed with thanks to @daniel-standage
1
vote
1answer
72 views

When does a chromatid become a chromosome?

When chromosomes lie on the metaphase plate, they have the characteristic X shape. But these are actually two chromatids that are held together at the centromere. If separation fails and both ...
1
vote
1answer
101 views

How was the origin of CTVT parasitic cancer determined?

The wikipedia article on CTVT says that the tumor cell has 57-64 chromosome while a normal dog has 78 chromosomes. Similarly while all chromosomes in dogs except the X and Y chromosomes are ...
1
vote
1answer
117 views

What does min mean?

I read that "trp operon is located at 27 min on E.coli chromosome." What does "min" mean ?
1
vote
1answer
146 views

Interlocus Contest Evolution means suicide?

I was reading Matt Ridley's "Genome" book. I am trying to understand the Interlocus Contest Evolution in his X-Y chapter. I do not understand why the X and Y chromosome would want to kill each other. ...
1
vote
1answer
37 views

Which sex is homogametic in side-blotched lizards?

I'm just trying to find out whether the male side-blotched lizard is the hetero- or homogametic sex in side-blotched lizards (Uta stansburiana) - some reptiles are ZW system (female heterogamete) and ...
1
vote
2answers
97 views

Does chromosomal crossover result in a mutation?

Is chromosomal crossover considered a mutation? Would this be a large-scale mutation?
1
vote
2answers
77 views

Referencing the homologous chromosomes

There exist a co-ordinate system from chromosomes like "12p11.3". In this system, first integer range from 1 to 23 i.e it takes homologous chromosomes as a pair. If we want to distinguish among ...
1
vote
2answers
778 views

what is knob heterochromatin?

I am reading a paper which discusses Maize Genome Structure. Descriptions of the structure is given in the papers introduction. I know about heterochromatin "heterochromatin stains intensely, ...
1
vote
1answer
3k views

Difference between Condensin and Cohesin proteins?

The chromosomal DNA is stacked with help of cohesin and condensin protein in which particular manner? Can cohesin be said to form kinetochore? How would they vary exactly? The terms are so narrowly ...
1
vote
0answers
15 views

Are both chromosomes transcribed and translated? [duplicate]

Or is it somehow regulated if both or only one chromosome is transcribed/translated?
1
vote
0answers
78 views

How do we know Denisovans had 46 Chromosomes

What allows sequencers to conclude that Denisovans had 46 chromosomes rather than merely knowing Denisovans had the crossover material arranged in 48 or say 44 chromosomes? See ...
1
vote
0answers
20 views

How to engineer chromosomal duplications?

Specific genetic engineering of chromosomal aberrations like deletions, inversions and translocations are doable by using the CRISPR/Cas system or the other programmable nuclease systems. Insertions ...
1
vote
0answers
43 views

Evolution of sexually concordant genetic variation on the X-chromosome

It was theorised in 1984 that sexually antagonistic genetic (SA) variation should more easily evolve on the X-chromosome. This is partly because female beneficial/male deleterious mutations face less ...
0
votes
3answers
58 views

Whole Genome Sequencing and B Chromosomes

Do whole genome sequencing techniques detect B chromosomes if such chromosomes are present? My understanding is as follows: How the DNA material in a B Chromosome is mapped depends on the reference ...
0
votes
1answer
137 views

Why do humans have 46 chromosomes? [duplicate]

Humans have approximately 25000 genes. Why are these genes on 46 chromosomes? Why not 40 or 50?
0
votes
1answer
31 views

Transcription when Chromosomes are Condensed

Are genes transcribed just as well when chromosomes are condensed? I want to design a screen that depends on genes not transcribed when chromosomes are condensed (to identify cells that can't ...
0
votes
1answer
59 views

What pattern can be learned from the data of RNA seq counts and HiC matrix? [closed]

I now have some data on the RNA seq counts and related Hi-C matrix of gene segment on a chromosome. My concern is, basically, what can we do with these data so as to establish the connection between ...
0
votes
2answers
119 views

Chromatids in metaphase?

Please see the following picture: In my book, the author claims that these chromosomes are in metaphase (a metaphase stopped by cholchicin). I don't understand why they don't have two ...
0
votes
2answers
58 views

about the direct intervention of a child's gender

Can we determine the gender of a child now,I mean,not randomly? There are equal amount of sperms with X chromosome and Y chromosome. Can these two kinds of sperms be distinguished easily? If yes,we ...
0
votes
1answer
23 views

Why does meiotic recombination disrupt the independent assortment of genes on the same chromosome?

There are many sources that say that genes that are "linked" by being on the same chromosome assort with each other -- that when an allele is passed on that the gamete containing said allele will also ...
0
votes
1answer
42 views

Maintenance of Diploid chromosome number at mitosis

I'm just not understanding this: A regular human cell is diploid - because it has 46 chromosomes, in 23 pairs. So that means that when the cell undergoes mitosis, it will still have the full ...
0
votes
0answers
38 views

Which chromosomes are J-shaped? [closed]

Are acrocentric chromosomes J-shaped or Sub-metacentric chromosomes J-shaped? I'm confused as different sources have different opinions. My text book considers acrocentric as J shaped and the ...
0
votes
0answers
85 views

What is the relation between chromomere & nucleosome?

I've been lately studying structure of chromosome where I got these two terms. I got many definitions of them. Nucleosome: The basic structural sub-unit of chromatin, consisting of $\sim 200$ base ...