Talk:Ploidy

message: What is the origin of the word 'ploidy'? A lack of familiarity with the root of this word is what makes it confusing to readers.  —Preceding unsigned comment added by 129.20.87.67 (talk) 09:42, 25 August 2009 (UTC)
replies: text:  Of course you're perfectly right, but philologists must just get over it. After all, bus is used as a noun (in English and many other languages), but omnis (all) is an adjective, and omnibus (for all, plural) too is certainly not a noun. Presumably Cicero would have found the use of -bus as a word in its own right pretty horrible, and I expect he would have made a fine speech about how the language of the heroes was being debased, but, well, it's what we do. Chiswick Chap (talk) 18:03, 15 January 2018 (UTC)
replies: text:  I agree no changes should be made. As ploidy is common usage among professionals in the field, that must be respected above any philologist' points. My remark was just to answer the long standing unsigned question put in talk. Uffe (talk) 20:36, 15 January 2018 (UTC)
thread_title:  Etymology 

message: There is little more than a dicdef here; I propose moving the Haploidy, Diploidy, Haploidisation, Polyploidy, and Aneuploidy pages to Ploidy.  You have to read all those articles to understand ploidy anywho.  I'll be happy to do the merge after approval.  Lefty 16:03, 2005 Mar 12 (UTC)
:also Haplodiploidy. Lefty 16:08, 2005 Mar 12 (UTC)
: Let's add Merodiploid while we're at it.Dr d12 (talk) 23:17, 27 February 2009 (UTC)
thread_title:  Old comment 

message: This is a confusing definition.  One might read this to mean "homologous sets" (ie: sets of homologous chromosomes), or homologous "sets of (non-homologous) chromosomes."  For example, the number of homologous sets of chromosomes in humans is 23 if one considers a "set" to be one pair of homologous chromosomes, or it could be 2 if one considers a "set" to be the collective number of non-homologous chromosomes.  
Ploidy therefore refers to the number of sets of non-homologous chromosomes, not homologous chromosomes.  Perhaps a more accurate definition would be something like, "Number of homologous sets of non-homologous chromosomes." 76.81.218.167 20:39, 3 August 2007 (UTC)
thread_title: "Number of ''homologous sets'' of chromosomes"?

message: Euploidy/aneuploidy can also be defined in terms of genomes (e.g. Kondrashov, AS. 1997. Evolutionary genetics of life cycles. Annu. Rev. Ecol. Syst. 28: 391-435) such that euploidy means having one or more complete copies of a genome. By this definition, eukaryote cells (which carry part of their genome in mitochondria and plastids as well as the nucleus) are frequently aneuploid, as there may be multiple copies of plastids/mitochondria present for each nuclear copy.
: Halfsnail 13:55, 31 May 2005 (UTC)
thread_title:  looking away from diplontic organisms.. 

message: Merge? I would prefer that Haplodiploidy is merged into Haplo-diploid sex-determination system, because it would then match the other articles on sex-determination system. Kirbytime 23:48, 12 April 2006 (UTC)
thread_title:  Haplodiploidy... what about [[Haplo-diploid sex-determination system]]? 

message: I'm pretty sure this section is wrong, according to my uni lecture notes and biology dictionary. I would just like someone else with a little more knowledge to write this correctly. As far as I can determine, euploidy is having integral multiples of the haploid number of chromosomes, i.e. haploid, diploid, triploid, tetraploid, etc. This seems to suggest to me that the euploid number (if there is such a thing) would be equal to the haploid number...? But i don't really want to put this in unless I am sure. -postglock 12:20, 30 July 2006 (UTC)
thread_title:  Euploidy 

message: What is a haploid cell?  The article only defines haploid number.  Is this a good definition:
"A haploid cell is one that contains half the number of sets of chromosomes that other cells of the organism contain."? -Pgan002 23:39, 27 September 2006 (UTC)
thread_title:  Haploid 

message: The section says "The gametes of common wheat are considered as haploid since they contain half the genetic information of somatic cells, but are not monoploid as they still contain three complete sets of chromosome from three species of organisms"
I'd therefore expect to see "x = 3n", but it says instead "n = 3x".
Am I missing something? —The preceding unsigned comment was added by Sagie (talk • contribs) .
:You are right. I've edited the article to follow. Thanks. -postglock 23:03, 14 November 2006 (UTC)
thread_title:  Haploid and monoploidy contradiction 

message: The article states:
:A haplodiploid species.... Most commonly, the male is haploid and the female is diploid. ...
:... One consequence of haplodiploidy is that the relatedness of sisters to each other is higher than in diploids....
This is a bit confused, since it has switched from dealing with haploid males and diploid females, to diploid males and haploid females, with no overt notice to the reader. Admittedly, the prior paragraph only says, "Most commonly," and I can follow it as I am familiar with the topic from reading Richard Dawkins' The Selfish Gene, but I think a reader trying to understand this for the first time might be thrown for a loop. — DavidConrad 04:19, 23 November 2006 (UTC)
thread_title:  Males and Females in Haplodiploid Species 

message: Should the article mixoploidy (currently just a stub) be merged here? --David Edgar 11:08, 20 February 2007 (UTC)
replies: text: I think so. Pgan002 21:54, 14 June 2007 (UTC)
replies: text: OK, I did it. --David Edgar 10:18, 15 June 2007 (UTC)
thread_title: Mixoploidy

message: The article says "Male bees, wasps and ants are also monoploid. For organisms that only ever have one set of chromosomes, the term monoploid is sometimes used interchangeably with haploid, but this is no longer the preferred terminology."  When I talk about hymenopteran reproductions, I always say "haploid male".  Should I be saying "monoploid male" instead?  But the article title is Haplodiploid sex-determination system; should the word "haplodiploid" become "monoplodiploid"?  Web searching on "monoplodiploid" gets precisely zero hits.  I think this supposed deprecation of "haploid" (to refer to a mature individual as opposed to gamete) is overstated.  Fungi are monoploid, but male bees are haploid. —   Randall Bart     Talk   19:14, 31 August 2007 (UTC)
thread_title:  Monoploid v Haploid 

message: It's pretty revealing when you have to go to the Talk Page to try to nut out what is being said in the article, and find there rather clearer definitions and explanations than in the article itself. Posters have been complaining about this "ploidy" stuff for years, but it looks just as bad now as it did then. Take the first par. 
Ploidy is the number of homologous sets of chromosomes in a biological cell. The ploidy of cells can vary within an organism. In humans, most cells are diploid (containing one set of chromosomes from each parent), but sex cells (sperm and egg) are haploid. In contrast, tetraploidy (four sets of chromosomes) is a type of polyploidy and is common in plants, and not uncommon in amphibians, reptiles, and various species of insects. 
First, the term “haploid” is utilized but not defined, which is a big no no.  When it is mentioned again, it is within a rather confusing context of monoploidy and haploidy. 
Second, raising the subject of the sex cells as compared to the somatic cells at this very early stage is unnecessary and likely to futher confuse the reader.  This topic should  be broachcd later. 
Third, all the definitions are thrown in holus bolus, without much logic as to how they are arranged. It appears that when all the different varieties of “ploidy” were amalgamated here, not enough effort was made to integrated them seamlessly. And often, technical terms are used without the author defining or explaining them. Further, some are just ambiguous. For example, what is a “unique chromosome” ? 
I’m not proficient in this field otherwise I’d have a go. But at the moment, the whole article is murky and badly organised. Could someone have a bash at this? Myles325a (talk) 22:52, 26 December 2008 (UTC)
replies: text: Your points are good ones, but I don't see any way to leave out sex cells in the intro, since the definitions of diploid and haploid rest on the chromosome numbers of zygotes and gametes respectively. How could we make this clearer?--Curtis Clark (talk) 02:58, 27 December 2008 (UTC)
thread_title:  Confusing from the first par 

message: "The exact number of chromosomes may be one or two different from the 2 number yet the cell may still be classified as diploid (although with aneuploidy)."
Is it just me, or is this sentence really unclear about what it's talking about? I would edit it to make it more understandable, but I'm not even sure what it's trying to say. Hopefully someone else can get in there and fix it. 68.205.84.223 (talk) 17:42, 14 January 2009 (UTC)
replies: text: Yes, I think it is better without that sentence, and have removed it. To call such organisms diploid is common, but rather careless terminology. "Diploid or near diploid" would be preferable. The explanation of aneuploidy higher up the page seems to be sufficient. Nadiatalent (talk) 12:44, 31 October 2010 (UTC)
thread_title:  1 or 2 different? 

message: Recent edits involved changing germ cell to sex cell and back again, when the meaning was post-meiotic cells. The wording was perfect as germ cells, e.g. http://www.medterms.com/script/main/art.asp?articlekey=8591
but the idea of distinguishing gametes from their precursors, and calling the precursors germ cells, seems to be overwhelming basic education, see for example:
http://www.khanacademy.org/video/mitosis--meiosis-and-sexual-reproduction?playlist=Biology
I've changed it back to sex cells, because students might have been trained to think that "germ cells" was wrong. Guess we'll have to work on explaining this all even more clearly. Nadiatalent (talk) 12:31, 31 October 2010 (UTC)
thread_title:  Germ cell versus sex cell 

message: In addition to all the problems noted above, the leading section of this article is not a summary, as it should be, but includes key material for understanding the article as a whole which is not repeated elsewhere. Peter coxhead (talk) 17:38, 18 December 2011 (UTC)
thread_title:  Inappropriate lead 

message: Could you explain the process (meiosis?) of reproduction from parents, 1 with diploid cells, the other with tetraploid cells?
In Oysters, it can lead to triploid new born oysters.
How is that?
As gametes should be haploid (= monoploid) !!!
The process of mixing diploids & tetraploids is a man made selection of sterile commercial shells.
What is the nature of the advantage of triploids?
Is this the sterility that preserves energy for faster growth?
I read tetraploid oysters are highly dangerous to the species, as in case of escaping out of laboratories, it could interact with wild oysters and generate sterile populations.
What about other species?
Could this happen elsewhere?
What is the connection with hybridization, such as for corn?  — Preceding unsigned comment added by 200.61.9.66 (talk) 16:35, 23 August 2013 (UTC)
replies: text: Fertilisation is the process involved. The diploid produces monoploid gametes (1x), and the tetraploid produces diploid gametes (2x). When these get together the result is triploid (3x) offspring. They are sterile because they can't neatly divide their chromosomes during meiosis. What happens in Taraxacum officinale pollen meiosis is that two sets of chromosomes evenly divide, but the third set gets scattered, so that overall, the gametes have all sorts of chromosome numbers, most about 1.5x. The gametes with strange chromosome numbers (not 1x or 2x) cannot make an offspring that develops normally because the genes on the chromosomes aren't properly balanced. In Taraxacum officinale it doesn't even get to that stage, the pollen grains don't develop properly and die. Yes, if  tetraploid oysters were released from a laboratory, their sperm and eggs would combine with sperm and eggs from the wild oysters, but those offspring would be sterile triploids. Yes, something similar could happen in other species, and it also happens in nature when a spontaneous tetraploid is formed. For the corn question you might want to look at Open pollination. Sminthopsis84 (talk) 14:06, 24 August 2013 (UTC)
thread_title:  Offspring of diploid + tetraploid parents 

message: The connection between "haploid" in the sense "one set of chromosomes present" and the use of the word in "haploid number" is not clear in the article. The article introduces the term "haploid number" before even defining "haploid", and the section "Haploid and monoploid" seems to think that it should start by defining "haploid number" even though it then goes on to use the word "haploid" in (as far as I can see) another sense.
Furthermore, haploid redirects to the section "Haploid and monoploid", but that section does not actually define what "haploid" means in any helpful way. Instead, it uses the term as if readers should already know. This is not very useful when clicking on links in other articles (e.g. "Each pollen grain is a male haploid plant" at Pollination, or "It produces gametes and is typically haploid" at Gametophyte). Reading the linked section does not shed any light on what a "haploid plant" might be, for instance.
I think someone familiar with the subject and article organisation should look at this. I don't feel confident about fiddling with it since I know nothing about the subject. 86.160.220.5 (talk) 20:34, 18 September 2013 (UTC)
replies: text: I think there's general agreement that the article is confused/confusing. There is a definition of "haploid" hidden in the lead section, which doesn't do what it's supposed to, i.e. summarize the article. However, no-one has yet come by with the expertise and time to sort this out. Peter coxhead (talk) 21:31, 18 September 2013 (UTC)
replies: text: Ok, I've attempted to rewrite the section Ploidy#Haploid and monoploid so that it's clearer. I would be grateful for any comments on whether I've succeeded! Peter coxhead (talk) 09:04, 19 September 2013 (UTC)
replies: text: Great work. As far as my original gripe is concerned it is much much better now. 86.128.4.139 (talk) 19:21, 19 September 2013 (UTC)

text: I'd like to try to rewrite more of the article, but then I run into the problem discussed in at least one thread above: sources are inconsistent and it's hard to write an account which maintains a neutral position but remains readable. Peter coxhead (talk) 21:27, 19 September 2013 (UTC)
thread_title:  Haploid 

message: Substituted at 03:08, 30 April 2016 (UTC)
thread_title: Assessment comment

message: The introduction states: a typical human somatic cell contains [...] 23 homologous chromosome pairs.
:This is factually incorrect, because the subscript of the first picture on page Homologous chromosome states:
::As this karyotype displays, a diploid human cell contains 22 pairs of homologous chromosomes and 2 sex chromosomes.
:Section structure of Homologous chromosome:
::Homologous chromosomes are chromosomes which contain the same genes in the same order along their chromosomal arms.
The picture in the introduction states: Diploid cells have two homologous copies of each chromosome.
:This contradicts with the last paragraph introduction Allele:
::If both alleles at a gene (or locus) on the homologous chromosomes are the same, they and the organism are homozygous with respect to that gene (or locus).
:Homologous chromosomes are usually not identical, but sister chromatids are.
::A sister chromatid refers to either of the two identical copies (chromatids) formed by the replication of a single chromosome.
I think the use of copies in the sense of non-identical copies leads to confusion, and that the adjective non-identical should at least be added to copies, if this is the intended meaning. Gravious (talk) 18:53, 8 March 2017 (UTC)
replies: text: It's clearly correct that the X and Y chromosomes in the males of organisms that have an X-Y sex-determination system are not "homologous" in the same way that the two X chromosomes are in females or the pairs of autosomal chromosomes are. On the other hand, there are regions in the X and Y chromosomes that are homologous and so allow pairing (see, e.g., this paper). It seems to be a case of a fuzzy use of "homologous" rather than actually being "factually incorrect". But I agree that some re-writing is needed. Peter coxhead (talk) 19:05, 8 March 2017 (UTC)
thread_title:  Number of homologous pairs 

message: This page, section "Diploid" contradicts the page on vischacha rats (https://en.wikipedia.org/wiki/Plains_viscacha_rat), where it says they used to be considered diploid but are no longer:
"However, careful analysis using chromosome paints shows that there are only two copies of each chromosome in T. barrerae, not the four expected if it were truly a tetraploid.[12] The rodent is not a rat, but kin to guinea pigs and chinchillas. Its "new" diploid [2n] number is 112 and so its cells are roughly twice what would normally be expected."
I suggest the following edit to that sentence:
"Nearly all mammals are diploid organisms (the tetraploid (four sets) golden vizcacha rat (Pipanacoctomys aureus)[24] is the only known exception as of 2005[25]), although all individuals have some small fraction of cells that display polyploidy."
Reference [25] here should be replaced with the one cited in the vischacha rat article (Svartman, Marta; Stone, Gary; Stanyon, Roscoe (2005). "Molecular cytogenetics discards polyploidy in mammals". Genomics. 85 (4): 425–30. doi:10.1016/j.ygeno.2004.12.004. .)
Tdbostick (talk) 13:59, 3 April 2017 (UTC)
thread_title:  viscacha rat contradiction 

message: Fascinating article, but I am left with two questions:
How is the ploidy of an organism determined by scientists?
And how long has it been understood? i.e. what is the history of scientific understanding of ploidy? Gebjon (talk) 09:26, 10 July 2020 (UTC)
replies: text: The first question has two parts. In the simplest meaning, which applies to virtually all animals, gametes are haploid and offspring produced by sexual reproduction are diploid. This is determined by staining cells and observing their nuclei under a microscope during the appropriate phases of mitosis and meiosis when the chromosomes have condensed and become visible and so can be counted. This is how we know that there are 23 chromosomes in a human gamete and 46 in a normal human cell. See Chromosome#History of discovery for the history. Counting chromosomes under a microscope is subject to error, and the wrong number was initially published for humans in 1923. In the second meaning, which applies to plants, ploidy refers to a hypothesis that the paired chromosomes in normal plant cells originated as multiple sets, e.g. by the original set of chromosomes doubling giving a tetraploid. Originally this was based on counts and appearance and comparison with relatives (e.g. if most species in a genus have 22 chromosomes in normal cells, but some species have 44, then it can be hypothesized that these are tetraploids). Now it's possible to sequence the genes of the organism and show that some chromosomes originated as duplicates perhaps after the merger of gametes from different species. Peter coxhead (talk) 10:54, 10 July 2020 (UTC)
replies: text: Thanks, that's very interesting. Would be great if the article could include that. Gebjon (talk) 16:11, 13 July 2020 (UTC)
thread_title:  How is ploidy determined and how long has it been understood? 

message: This recent edit by an IP editor, which they then undid, does raise the issue of whether the term set is used consistently and clearly in the article. A set of chromosomes could have two possible meanings in terms of its composition:
#one of each different chromosome, so there are 23 chromosomes in a set of human chromosomes, and two sets of 23 in a normal diploid human
#one of each homologous chromosome, so there are 23 sets of two chromosomes in a normal diploid human; a hypothetical triploid human would have 23 sets of three chromosomes.
I think it's clear that the first meaning is intended throughout, but I'm wondering if the introduction could make this even clearer, although I can't at present come up with the right wording. Peter coxhead (talk) 17:48, 8 November 2023 (UTC)
thread_title: Meaning of ''set''

message: The claim that the mammalian liver is polyploid despite diploidy being the normal state for mammalian cells links to the liver article, but liver does not discuss ploidy at all. I have therefore added a  to the claim.  166.181.81.124 (talk) 10:29, 19 May 2024 (UTC)
thread_title:  Polyploidy of the mammalian liver