What happens when polyploidy has taken place?

polyploidy, the condition in which a normally diploid cell or organism acquires one or more additional sets of chromosomes. ... If through polyploidy, however, the plant duplicates the chromosome set inherited from each parent, meiosis can occur, because each chromosome will have a homologue derived from its duplicate set.

1. What happens when polyploidy occurs?
2. How can polyploidy lead to new species?
3. How does polyploidy affect diversity?
4. What is the function of polyploidy?
5. What is the result of polyploidy in humans?
6. How polyploidy resulted in evolution of new crop species?
7. Why is polyploidy important in evolution?
8. Why does polyploidy in plants immediately result in the formation of a new species?
9. What is polyploidy explain origin & effects of Autopolyploidy?
10. Has the connection between polyploidy and diversification actually been tested?
11. What is polyploidy in pharmacognosy?
12. What is the role of polyploidy on the hybridization of plants?
13. Is polyploidy lethal in humans?
14. Can polyploidy be passed on?
15. Which of the following cell cycle event is responsible for polyploidy phenomenon?

What happens when polyploidy occurs?

Polyploidy can also be problematic for the normal completion of mitosis and meiosis. For one, polyploidy increases the occurrence of spindle irregularities, which can lead to the chaotic segregation of chromatids and to the production of aneuploid cells in animals and yeast.

How can polyploidy lead to new species?

Polyploidy typically results in instant speciation—the new polyploid may be immediately isolated reproductively from its parent or parents; this process greatly increases biodiversity and provides new genetic material for evolution.

How does polyploidy affect diversity?

Polyploidy has significantly enhanced the physical and biochemical diversity of plants. The increased size of many polyploids relative to their diploid parents has been particularly useful in breeding ornamental plants with larger, showier flowers.

What is the function of polyploidy?

Polyploidy is a major force in the evolution of both wild and cultivated plants. ... Some of the most important consequences of polyploidy for plant breeding are the increment in plant organs ("gigas" effect), buffering of deleterious mutations, increased heterozygosity, and heterosis (hybrid vigor).

What is the result of polyploidy in humans?

Polyploidy occurs in humans in the form of triploidy, with 69 chromosomes (sometimes called 69, XXX), and tetraploidy with 92 chromosomes (sometimes called 92, XXXX). Triploidy, usually due to polyspermy, occurs in about 2–3% of all human pregnancies and ~15% of miscarriages.

How polyploidy resulted in evolution of new crop species?

For a long period of time, polyploidy in plants has been considered to be an important phenomenon because of genome buffering, increased allelic diversity, fixing heterozygosity and the opportunity for novel phenotypic variations because of duplicated genes which acquire new function (Stebbins, Variation and evolution ...

Why is polyploidy important in evolution?

Accumulating evidence indicates that polyploidy can increase mutational and environmental robustness, which might increase the potential for specific adaptation in response to changing environmental conditions or reduce the risk of extinction during periods of environmental upheaval.

Why does polyploidy in plants immediately result in the formation of a new species?

Normally a hybrid is sterile because it does not have the required homologous pairs of chromosomes for successful gamete formation during meiosis. ... Thus, polyploidy confers fertility on the formerly sterile hybrid, which thereby attains the status of a full species distinct from either of its parents.

What is polyploidy explain origin & effects of Autopolyploidy?

Polyploidy can occur when an error during meiosis leads to the production of unreduced (i.e., diploid) gametes rather than haploid ones, as shown in Figure 6.1. If two diploid gametes fuse, an autotetraploid will be created whose nucleus contains four copies of each chromosome.

Has the connection between polyploidy and diversification actually been tested?

A direct test of diversification following polyploidy requires a sequence-based approach that traces the history of nuclear genomes rather than species. ... Limitations of existing methods mean that the connection between polyploidy and diversification has not been rigorously tested and remains unknown.

What is polyploidy in pharmacognosy?

Polyploidy is the strength of modern genetics or modern molecular technology in. pharmacognosy to provide something new or combinations of characters in the field of plant breeding programs. of medicinal plants and also for foods or crops.

What is the role of polyploidy on the hybridization of plants?

Polyploidy is arguably the major feature of plant genome evolution, doubling the number of copies of each gene with each WGD event. Over evolutionary time, polyploids have displaced all their diploid ancestors several times in multiple independent lineages, suggesting a strong selective advantage.

Is polyploidy lethal in humans?

Interestingly, polyploidy is lethal regardless of the sexual phenotype of the embryo (e.g., triploid XXX humans, which develop as females, die, as do triploid ZZZ chickens, which develop as males), and polyploidy causes much more severe defects than trisomy involving the sex chromosomes (diploids with an extra X or Y ...

Can polyploidy be passed on?

Many polyploids are infertile, depending on the number of chromosome sets they have inherited. ... If the individual has an even number of chromosome sets, they are usually fertile. This is because the chromosomes can still pair up during meiosis and produce functional gametes.

Which of the following cell cycle event is responsible for polyploidy phenomenon?

Polyploidy is the phenomenon of having more than two genomes or two sets of chromosmes. It occurs in nature due to the failure of chromosomes to separate at the time of anaphase either due to non-disjunction or due to non-formation of spindle. Cytokinesis does not occur after telophase stage leading to polyploidy.