All Questions
Tagged with chromosome dna
54 questions
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Can a deletion occur on only one strand of a human chromosome?
Hello. Is it possible that a deletion can occur in the middle of only one strand of a human autosomal chromosome?
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1
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209
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Are DRB3 DRB4 and DRB5 different genes or different version of the same gene
From what I understand, an individual can hold up to two HLA-DRB345 alleles (but can be less) that can each be HLA-DRB3, HLA-DRB4 or HLA-DRB5.
However, since HLA-DQB1 and HLA-DQB2 are entirely ...
4
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1
answer
142
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What makes protein binding to the DNA random?
We know that the genetic recombination process in known as a random process. On the other hand, it has also been discovered that certain proteins (such as PRDM9) determine what recombination hotspots ...
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0
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What is the DNA sequences between two Inverted Repeats called?
I would like to know some rules about the nomenclature of Inverted Repeats DNA sequences. More in detail, I want to know what is the name of sequences between two inverted repeats.
For example, I have ...
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How much is known about dinosaur DNA condensation and crosslinking?
The conclusion section of Bailleul et al. (2020) Evidence of proteins, chromosomes and chemical markers of DNA in exceptionally preserved dinosaur cartilage is:
The identification of chemical markers ...
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2
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137
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Are the complementary base pairs known as genes? [closed]
In my text book ,it is written that a chromosome has 1000s of genes and it is distributed throughout the chromatids except in the centromere. But we know that the chromosomes have DNAs inside them ...
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1
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293
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What is prochromosome?
My textbook says that prochromosome is a false chromosome present in the nucleoid of prokaryotes.
I looked up Wikipedia and all over internet and this word is kinda sus. So I'm asking about it here. ...
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When the sister chromatids are joined in the centromere, why is it stated that the number of chromosomes is 46 and not 72?
Before the DNA is replicated in a human somatic cell, the cell has 46 chromosomes. Also, after the sister chromatids are separated during Anaphase, the chromosome number in the cell doubles to 72, so ...
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What is the structure of heterochromatin?
A short article about euchromatin and heterochromatin mentions that the structure of heterochromatin usually depicted in images "has never been visualized in vivo, and its existence is ...
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Do we come to know which allele is dominant by seeing family genration tree only?
I know that a Gene has Alleles (variation) and one is Dominant over Other i.e the Other Recessive.
Then I got a Thought that How can we tell whether an Allele is Dominant or Recessive...... and I came ...
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Why do some karyotype graphs contain 46 pairs of chromosomes?
The human genome consists of 23 pairs of chromosomes. Two copies of each pair connect to each other at the centromere. Normal karyotype graphs should look like this:
But some karyotype graphs contain ...
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Does DNA being circular or linear directly affect the speed of DNA replication?
Let's say we have two DNA molecules of equal length, one belonging to a prokaryote and the other to an eukaryote. It's known that replication of the eukaryotic DNA is faster in this case. One clear ...
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207
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What causes cells to inactivate one X-chromosome?
Normally, when a cell has two X-chromosomes (female genome), one is randomly inactivated. How does the cell detect that there are two X-chromosomes in the first place?
Is there some kind of protein ...
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-4
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1
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224
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In a Chromosome, 2 nm is the length of what?
this figure comes from the nature
2 nm at the top right hand corner is the length of what?
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134
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Number of DNA strands per chromosome
As I was reading Griffith's Introduction to genetic analysis this evidence was provided for single DNA makes single chromosome.
Eventually geneticists demonstrated directly that certain chromosomes ...
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Possible combinations in the Meiosis' Telophase 1
As you might already know
Meiosis is the process in eukaryotic, sexually-reproducing animals that reduces the number of chromosomes in a cell before reproduction $^{[1]}$
One of the reasons why ...
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Offspring of parents with different number of chromosomes
Many papers report that dog-whelks (Nucella lapillus) show a distinct chromosomal polymorphism between populations of 2n = 24 up to 2n = 36. Could somebody please tell me how many chromosomes the F1 ...
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What is a chromosome?
I read the wikipedia article and am confused if a chromosome is the pair of two chromotoids or if each chromatoid is considered a chromosome.
I've heard someone say we have 23 pairs of chromosomes ...
user46122
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Human genome, chromosomes
I have a very basic question, but it seems the hardest to me.
So we have 46 chromosomes (23, 2 copies of each). Do all chromosomes have the same DNA? If so, does it mean that in different cells with ...
2
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2
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800
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Why the genome is divided into several chromosomes and not just a single big chromosome?
In many eukaryote species, there are several chromosomes. In humans, for example, there are 23 pairs of chromosomes.
Why are there several chromosomes and not just a join of all chromosomes into a ...
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1
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58
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How does the number of chromosomes evolve through generations? [duplicate]
Mitosis is a complex mechanism that, through mutations and crossover, determines how a chromosome is composed. But at that point, the number of chromosomes is already determined: how can this number ...
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2
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Do chromosomes change with time?
An offspring is 23 chromosomes of mother and 23 of father, if one of the mate learns say music after the birth of their first child— will their second offspring have better music skills than former? ...
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Are there examples of cells with more than one nucleus?
I've always wondered why cells have only one nucleus, as having multiple would seemingly prevent mutation. Are there examples of organisms with multiple nucleuses? If not, is there a reason?
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Don't understand how multiple replication bubbles work
I'm not exactly sure how multiple replication bubbles work, assuming were working with a linear, eukaryotic chromosome.
This is a diagram for reference:
It appears that the DNA is being synthesized "...
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How do biologists determine the parents of a child
I am not well-versed in biology so this question might be wrong. As far as I understand meiosis, two germ line cells with 23 chromosomes each (one cell from the father and another from the mother) ...
user38033
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Why does cell waste energy in meiosis, between meiosis 1&2
As far as I have learnt about meiosis I have read that anaphase 1 is followed by telophase 2 where chromosomes change back to reticulum.but in the very next stage i.e prophase 2 they again start ...
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Stability of the chromosomes of thermophilic bacteria
We know thermophiles — generally archaebacteria — can survive high temperature, but their genomic DNA also contains hydrogen-bonded nitrogen bases. Why don't they collapse like ordinary hydrogen bonds?...
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Zygosity and Strands
I am not a biology expert but I have done some homework on understanding alleles, chromosomes, dna in the human genome. Still baffled by a question though:
As I understand it at a particular locus ...
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596
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Will a person with two copies of the same set of chromosomes be normal?
Would a (theoretical) woman (because she must have two X's), that both sets of
her chromosomes were 100% identical, be "normal"?
Would she be healthy, or would she have genetic problems as a result ...
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938
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Do telomeres appear at just one end of the chromosome?
I have just studied DNA Replication for my Biology Class and I have this question that leaves me stuck, though I have tried to figure it out myself.
During telomere replication, I am aware Telomerase ...
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Do all chromosomes in one human body contains same genome? [duplicate]
As I understand it, each nucleus of a cell contains multiple chromosomes. Each chromosome has multiple DNAs. Each DNA contains some specific gene sequences. That sequence is called Genome.
My ...
user28169
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Are all 23 chromosomes connected as one long strand of DNA? [duplicate]
This has perpetually confused me. Is our genome made up of two long strands, each strand made up of 23 continuous chromosomes that bind together, or are they 23 free floating separate pair of ...
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1
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What exactly are genes, DNA and chromosomes. How do they relate to each other and what is their function? [closed]
So I am new to biology and I have been reading, and searching the web, but I couldn't understand the whole framework of a cell. So as I understood:
A DNA, is a double chain of Nucleotides (A,T,G,C ...
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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 ...
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1
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Why does size decrease across the sequence of human chromosomes?
The following graph shows a decrease in the number of base pairs per chromosome across the sequential set of human chromosomes:
Is this because chromosomes were originally numbered by their size on ...
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Are genes uniformly dispersed throughout the genome?
I think that telomeres and centromeres are regions with a very low gene content (= regions that contain few genes). To the exception of telomeres and centromeres, are genes uniformly distributed ...
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What does it mean to "map the human genome"
I know some elementary chemistry and biology. I also think I know what a gene is (it's a sequence of DNA which encodes a particular protein). I also know that on a chromosome there are sections of DNA ...
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Is the size of the genome across species roughly the same?
Chromosome number differs across species.
Is the amount of DNA comparable between organisms, just being split into smaller chunks in those species with more chromosomes, or do species have different ...
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What determines the number of chromosomes an organism carries?
This is an extension of this question about What limits chromosomal length?.
I am wondering what could be the specific reasons behind the number of chromosomes an organism carries. In other words, ...
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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 ...
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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 ...
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Chromosome and chromatid numbers during cell cycle phases
A diploid cell in G1 has 6 chromosomes. How many chromosomes and how many chromatids are present in each of the following stages?
Here is what I am guessing
G1: 6 chromosomes ; 6 chromatids
G2: 6 ...
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4
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1
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Clarification on the "orientation" of chromosomal rearrangements
I need some clarifications on the concept of "orientation" in case of chromosomal rearrangements.
Given a deletion event on a chromosome for example, is the resulting DNA at the breakpoint always in ...
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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 chromatids...A ...
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1
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How much DNA of Albert Einstein is recoverable?
Since there seem to be five biological descendants of Albert Einstein, and the original chromosomes of him distributed among them ...
Is it possible to recover enough DNA of an individual from his ...
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1
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3k
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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 ? ...
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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 ...
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1k
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Question about Autosomal Recessive Alleles
I had a homework question that I could not figure out.
It states:
A woman has cystic fibrosis in her family and did not want to have a
child that suffered from the disease. She and her spouse ...
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1
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What is the most genetically simple organism except viruses?
What is the most genetically simple organism (except viruses) on this planet?
By simple I mean the least number of genes.
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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 ...
user3064