Why do the chromosomes line up in the middle of the cell?
ANSWER:
Chromosomes line up at the metaphase plate, under tension from the mitotic spindle. The two sister chromatids of each chromosome are captured by microtubules from opposite spindle poles. In metaphase, the spindle has captured all the chromosomes and lined them up at the middle of the cell, ready to divide.
Chromosomes line up at the metaphase plate, under tension from the mitotic spindle. The two sister chromatids of each chromosome are captured by microtubules from opposite spindle poles. In metaphase, the spindle has captured all the chromosomes and lined them up at the middle of the cell, ready to divide.
The parents are of genotype heterozygous dominant and homozygous recessive. Supposing the dominant allele is N and the recessive allele is n, one of the parents will be Nn while the other nn. The phenotypic (based on visible characteristics) ratio will be 1:1 for dom/rec and rec/rec as indicated in the diagram below.
On May 18, 1980, an earthquake struck below the north face of Mount St. Helens in Washington state, triggering the largest landslide in recorded history and a major volcanic eruption that scattered ash across a dozen states
