Answer:
Tetraploid wheat evolved by allopolyploidization and subsequent diploid-like behavior due to cytological diploidization
Explanation:
Durum wheat (<em>Triticum durum</em>) or pasta wheat, is a tetraploid wheat species that has 28 chromosomes, i.e., seven pairs in each genome (2n = 4x = 28). Durum wheat was domesticated from wild emmer wheat, which originated by hybridization of two diploid wheat species with 14 chromosomes: <em>Triticum monococcum</em> (genome AA) and one wild progenitor (genome BB). <em>Triticum durum </em>is a typical example of evolution by hybridization and polyploidization, where the resultant tetraploid species has two complete sets of chromosomes. Allopolyploidization is one of the most common types of plant speciation. During meiosis, 28 chromosomes form 14 homologous chromosome pairs, because homologous chromosomes have developed 'restriction of pairing' (i.e., cytological diploidization). The restriction of pairing to fully homologous chromosomes ensures a correct meiotic behavior, which otherwise would be altered due to the high level of homology that still exists among chromosomes from different wheat progenitors.
<span>hello there hester , i would say needed to form cell membranes</span>
When currents happen little waves are being pushed toward the shore or away from the shore. When being pushed toward the shore cool air is being blown toward land making the air cooler. for exaple the air near a beach will be cooler at night because of ocean breeze
Answer:
The suprachiasmatic nuclei enable the nervous system to respond to daily light/dark alterations through their stimulation of melatonin.
Explanation:
Melatonin is a hormone produced naturally by the body. Its function is to regulate the body's circadian cycle. This hormone is stimulated and begins to act by changing between a light environment and a dark environment. This stimulation interacts with the suprachiasmatic nuclei making the nervous system understand this change and luminosity of the environment and respond to the action of melatonin.
