Answer:
Chitinous exoskeleton and segmented bodies.
Explanation:
Phylum Arthropoda are known as jointed legs species which include crabs, spiders, ants, etc. The important characteristic of Arthropoda is they have a hard chitinous exoskeleton that provides them protection and gives flexibility. These phylum species can survive in both terrestrial and marine habitats. Some characteristics of phylum Arthropoda are given below:
1) They have Chitinous exoskeleton which is hardened.
2) Their digestive tract is present at opposite ends of the body and complete with the mouth and anus.
3) They contain jointed limbs.
4) The body structure of these species is showing bilateral symmetry.
DNA.
DNA has a phosphate and deoxyribose sugar backbone.
Answer:
1. The physiological changes that will occur when someone lives at altitude for an extended period include increased production of more red blood cells.
2. The changes are advantageous as the person can survive lower altitude better and strenuous activities that interferes with breathing.
3. The specific physiological pathway that results in the changes described involves decrease in pulmonary ventilation at high altitude leading to hypoxia then hypoxemia. The body then produces more red blood cells to counteract the lower oxygen saturation in blood in high altitudes.
Phylogenetic bracketing is a technique for surmising utilized as a part of organic sciences. It is to deduce the probability of obscure attributes in life forms in view of their position in a phylogenetic tree. One of the primary utilizations of phylogenetic sectioning is on wiped out creatures, known from fossils.