diploid vs haploid?????? | Yahoo Answers
There are two types of cells in the body - haploid cells and diploid cells. The difference between haploid and diploid cells is related to the number of. Once it comes to guessing a dire topic, understanding on and, per times, guessing your dishonors can isle a dire difference. The long-term trousers per these. Diploid vs Haploid: Haploid cells contain one full set of chromosomes, and are usually germ cells. Diploid cells contain two full sets of chromosomes. College EntranceUp-to-date learning supplements for SAT and ACT.
Metaphase 1 - in this phase, tetrads system at the metaphase plate and the centromeres of the homologous chromosomes become oriented towards either side of the cell poles.
Anaphase 1 - the chromosomes start moving to the opposite poles of the cells. The microtubules and kinetochore fibers also interact and there is movement.
Unlike in mitosis, homologous chromosomes move to the system poles but sister chromatids remain together. The spindle fibers fission moving homologous chromosomes to the poles after which either pole has a haploid number of chromosomes.
Cytokines also tend to occur spontaneously. Two daughter cells are formed each containing a half number of chromosomes what the original parent cell. In this stage, 60s nuclear best options trading book as well as the nuclei binary and best broker for option trading spindle fibers reappear.
The chromosomes then start migrating to the equator of the cell.
Diploid vs haploid??????
Gametophytes were cultivated in the laboratory to enable gametogenesis and then the sporophytic recruits were identified to species level. Future work could make use of the availability of more powerful tools with which to incorporate the microscopic gametophyte stage, rather than only looking at the sporophytic stage e. Red seaweeds Red seaweeds have a unique life cycle amongst the haploid-diploid cohort of organisms.
Genetically-speaking, the red algal life cycle is biphasic with the alternation of two different ploidies, the diploid sporophytes called tetrasporophytes and the haploid gametophytes. Unlike other life cycles, there is a third phase, the carposporophyte or the cystocarp that is found on the female thallus in which a zygote is mitotically amplified through a polyembryonic process.
The resulting diploid spores from a single cystocarp are genetically identical and settle to form the diploid free-living stage. The biphasic life cycle of Chondrus crispus. In theory, every single carpospore can germinate into a tetrasporophyte. Moreover, red algal fertilization success was thought to be so poor due to the lack of motile male gametes, the short viability of the male gametes and the retention of the female gamete on the maternal thallus.
Thus, the zygotic amplification in the cystocarp maximized a rare, but successful fertilization event.
Haploid-diploidy, a (brief?) history |
Tidal height had a significant impact on genetic structure in which the high shore populations were more isolated.
It is incredibly difficult to discern where one individual ends and the next begins. Nevertheless, tidal height once again had a significant effect on genetic structure where the high shore was more isolated. Haploid-diploid life cycles should, perhaps, tend toward endogamy because the haploid stage will expose the genome to selection.
More species from different red algal orders should be studied to compare the variation in mating system, not only across species, but also across geographic regions. For example, kelp forests are extremely important near-shore communities, harboring high species diversity. However, kelps are also intensely harvested along coastlines around the world, not to mention also cultivated at industrial scales in marine farms.
Where are the centers of genetic diversity? Do they happen to also be areas of intense harvesting practices? This would result in an individual with cells of differing chromosome numbers, which would result in genetic mutations. If chromosome reduction did not occur in meiosis, the combination two cells to form offspring would result in offspring with double the number of chromosomes of either of its parents or a 4n chromosomal set.
This offspring would then be another species. If chromosome reduction did not occur in mitosis, the resultant daughter cells would each contain a 4n chromosomal set, and so would be incompatible with the rest of the organism. The processes of mitosis and meiosis are structured to ensure that the number of chromosomes of the offspring reflects that of the parent. However, sometimes things go wrong, and this is not the case. Nondisjunction occurs when karyokinesis does not occur properly: Monosomy occurs after nondisjunction, in the daughter cell containing fewer chromosomes — this cell will contain one fewer chromosome or one chromosome where it should contain two.
The other daughter cell will exhibit trisomy — it will contain one extra chromosomeor three chromosomes where it should contain two. Polyploidy occurs when a cell contains more than two haploid chromosome sets such as triploid or tetraploid cells. Autopolyploidy means that more than two haploid chromosome sets of the same species are present; this can occur as a result of incomplete segregation in meiosis, or if two sperm cells fertilize the same egg cell.
Haploid-diploidy, a (brief?) history
Allopolyploidy results when the parent cells are not of the same species, resulting in a daughter cell containing a complete diploid chromosome set from each parent cell.
An example of this is a mule, which is a cross between a horse and a donkey. Such organisms are usually sterile. The result of these events is aneuploidy or a cell that does not contain a diploid chromosome number.
This is the basis of many genetic diseases, such as Down syndrome resulting from trisomyor Edwards syndrome also resulting from trisomy.Chromosomes and Karyotypes
The full chromosome set of a woman with Down syndrome. Trisomy occurs on the 21st chromosome. Wikimedia Commons Other abnormalities in chromosome sets include a change in the arrangement of the chromosomal set. A deletion of part of a chromosome, in humans, can lead to diseases such as cri du chat syndrome; a repetition of part of a chromosome resulting from unequal crossing over of genetic material during meiosis.
Inversions of gene sequences, translocations of chromosome segments, can result in familial Down syndrome in humans; and fragile sites in chromosomes, such as Martin-Bell syndrome in humans, a common cause of mental retardation. What is the Difference Between Haploid and Diploid? What Does it Mean?
Diploid vs Haploid: Similarities and Differences | uzveli.info
A haploid chromosome set occurs in eukaryotes when a sex cell or gamete is produced. This cell contains half of the genetic material, or chromosomes, of its parent cell.
A diploid chromosome set occurs in most eukaryotes in somatic cells — that is, non-sex cells. These cells contain the entire set of genetic material, or chromosomes, of the organism, or double the haploid chromosome set.