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This image shows haploid (single), diploid (double), triploid (triple), and tetraploid (quadruple) sets of chromosomes. Triploid and tetraploid chromosomes are examples of polyploidy. Polyploidy is a condition in which the cells of an organism have more than two paired sets of ( homologous ) chromosomes .
Grass carp inhabit lakes, ponds, pools and backwaters of large rivers, preferring large, slow-flowing or standing water bodies with abundant vegetation. [5] In the wild, grass carp spawn in fast-moving rivers, and their eggs, which are slightly heavier than water, develop while drifting downstream, kept in suspension by turbulence.
The list of organisms by chromosome count describes ploidy or numbers of chromosomes in the cells of various plants, animals, protists, and other living organisms.This number, along with the visual appearance of the chromosome, is known as the karyotype, [1] [2] [3] and can be found by looking at the chromosomes through a microscope.
In plants, this probably most often occurs from the pairing of meiotically unreduced gametes, and not by diploid–diploid hybridization followed by chromosome doubling. [39] The so-called Brassica triangle is an example of allopolyploidy, where three different parent species have hybridized in all possible pair combinations to produce three ...
Triploid block is a phenomenon describing the formation of nonviable progeny after hybridization of flowering plants that differ in ploidy. The barrier is established in the endosperm, a nutritive tissue supporting embryo growth. [1] [2] This phenomenon usually happens when autopolyploidy occurs in diploid plants.
Asian carp is an informal grouping of several species of cyprinid freshwater fishes native to Eurasia, commonly referring to the four East Asian species silver carp, bighead carp, grass carp (a.k.a. white amur) and black carp (a.k.a. black amur), [note 1] which were introduced to North America during the 1970s and now regarded as invasive in the United States.
Common carp by Alexander Francis Lydon. The type subspecies is Cyprinus carpio carpio, native to much of Europe (notably the Danube and Volga Rivers). [2] [4]The subspecies Cyprinus carpio haematopterus (Amur carp), native to eastern Asia, was recognized in the past, [4] but recent authorities treat it as a separate species under the name Cyprinus rubrofuscus.
An endosperm is formed after the two sperm nuclei inside a pollen grain reach the interior of a female gametophyte or megagametophyte, also called the embryonic sac.One sperm nucleus fertilizes the egg cell, forming a zygote, while the other sperm nucleus usually fuses with the binucleate central cell, forming a primary endosperm cell (its nucleus is often called the triple fusion nucleus).