Answer:
Explanation:the cranial end of the neural tube closes by 24days and the caudal 25-36 days . Defective closure of the neural tube result in neural tube defects (NTDs) . it also depends on the point of the defect , NTDs may also affect the brain and spinal cord.
Light waves or gravitational waves sorry if not correct
Answer:
Proteoglycans are a major component of compact connective tissues but are relatively unimportant in watery tissues such as the jellylike substance in the interior of the eye.
Explanation:
these are protein that is divided into two classes which are called large ans small Proteoglycans.
The large proteoglycans has a large number of highly sulfated glycosaminoglycan side-chains that tends to hold water and whereby making the tendon to resist compression while the small proteoglycans are known to have a relationship with collagen fibrils which are known to regulate collagen fibril diameters. they help in signal regulation usually from the angle of intracellular compartments. the are known great for their large diversity especially in terms of different cores and different numbers of GAGs with different lengths and composition.
I think the answer is evolution.
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.