Yes, these are considered organs. The skin and the bones both fall under the definition of an organ.
Answer:
The presence of an additional chromosome
Explanation:
Look at "pair" 21. See how there are THREE chromosomes instead of TWO? Normally, there would only be two chromosomes in each pair but this karyotype shows a trisomy (see def. below) of the 21st pair. This was caused by a nondisjunction mutation of the 21st pair. The is also the karyotype of a person with Down's Syndrome.
Definition of Trisomy:
A condition of the presence of three chromosomes in a pair instead of two. This normally causes developmental irregularity.
Answer:
tertiary; quaternary
Explanation:
The orientation of all the atoms of a protein in three dimensions represents its tertiary structure. It includes the folding of the polypeptide chains in a way that brings are far apart amino acids of its secondary structure close together. Various segments of a polypeptide chain interact to form tertiary structures and these segments are held together by different kinds of weak interactions.
However, disulfide cross-links between the segments of polypeptide chains also stabilize the tertiary structure of some proteins. Likewise, disulfide bonds also hold the protein subunits of some proteins together and thereby, contribute to the quaternary structure. For example, two light chains of an antibody are joined together by disulfide bonds.
