This question lacks options, options are: A) Heterochromatin and euchromatin
B) Uniform in the genetic information they contain
C) Separated by large sketches of repetitive DNA
D) Each void of typical protein-coding sequences of DNA
E) Void of introns.
The correct answer is A.
Explanation:
The chromatin or substance that makes up the nuclei of cells and that results from the interaction of DNA with histonic and non-histonic proteins and RNA; it can present different degrees of packing or contraction. When chromosomes are stained with chemicals that bind to DNA, densely stained regions and less densely stained regions appear. Heterochromatin are segments of the chromosome that stain strongly and remain visible, practically, during the entire cell cycle. There are few genes in these regions and therefore low transcriptional activity. They are supercondensed regions. Euchromatin are segments of the chromosome that are not visible during telophase and interphase, only in metaphase. It corresponds to regions that are less compact and in which there is a higher gene density.
The Agouti gene controls the distribution of black pigment. The dominant allele A restricts black pigment to the points of the horse (mane, tail, lower legs and ear rims), as seen, for example, in bays and buckskins.
