Answer:
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.
Bicarbonate buffer system. Human blood contains large amounts of carbonic acid, which is a weak acid, and bicarbonates, a strong base. If blood pH falls below 6.8 or rises above 7.8, one can become sick or die. This bicarbonate buffer system help maintain blood pH at 7.4. The bicarbonate neutralizes excess acids in the blood while the carbonic acid neutralizes excess bases.
The skeletal system since the brain is apart of the skeletal system.
Answer: The dependent variable.
Explanation: Experimental studies are designed to find relationships between one variable and another.
