Answer is D.
you can learn A,B, and C from examining fossils
A chromosome contains one long DNA strand.
B.
Twelve pairs of ribs are attach to the second spinal region which is called the thoracic. Thoracic spine is kyphotic. Kyphotic means excessive curvature of the spine as it occurs in thoracic and also sacral regions. Thoracic spine is located in the chest area.The ribs are attach to the thoracic spine and protect the vital organs that is located thoracic spine region.
1st one, fats/phospholipids/steroids.
2nd one, cholesterol and saturated fats.
I believe the primary structure will be preserved. The secondary level of proteins is defined by patterns of hydrogen bonds between the main chain peptide groups. Therefore distorting the Hydrogen bonds disrupts the secondary structures. The primary structure on the other hand is not affected by disruption of the hydrogen bond since these structures refers to the sequences of amino acids in the polypeptide chains that are joined by the peptide bonds.
