The randomness in the alignment of recombined chromosomes at the metaphase plate, coupled with the crossing over events between nonsister chromatids, are responsible for much of the genetic variation in the offspring. To clarify this further, remember that the homologous chromosomes of a sexually reproducing organism are originally inherited as two separate sets, one from each parent. Using humans as an example, one set of 23 chromosomes is present in the egg donated by the mother. The father provides the other set of 23 chromosomes in the sperm that fertilizes the egg. Every cell of the multicellular offspring has copies of the original two sets of homologous chromosomes. In prophase I of meiosis, the homologous chromosomes form the tetrads. In metaphase I, these pairs line up at the midway point between the two poles of the cell to form the metaphase plate. Because there is an equal chance that a microtubule fiber will encounter a maternally or paternally inherited chromosome, the arrangement of the tetrads at the metaphase plate is random. Thus, any maternally inherited chromosome may face either pole. Likewise, any paternally inherited chromosome may also face either pole. The orientation of each tetrad is independent of the orientation of the other 22 tetrads.
Explanation:
Answer:
450 years
Explanation:
well, according to some researchers, They estimate that due to the PET used in objects like plastic bags, plastic water bottles and plastic straws, it could take upwards of 450 years to decompose.
Answer: The electron transport chain consists of complexes which are the proton pump for the hydrogen ions across the mitochondrial membrane which allows the synthesis of the ATP (energy currency).
Explanation:
The electron transport chain occurs in the mitochondria. ATP synthase present in the inner mitochondrial membrane is a carrier of electron. FADH2 AND NADH two molecules supply high energy electrons from the citric acid cycle from the electron transport chain at complex I (NADH coenzyme Q reductase) and II (succinate dehydrogenase)respectively.
The mechanism is straightforward: in Metaphase one of Meiosis, chromosomes line up in two lines, with homologous across from each other, which allows them to interact by crossing over. In Metaphase of Mitosis, the chromosomes are all lined up single file, so the homologous chromosomes cannot interact.
