Elderly people are most at risk
from minor trauma that results in serious spinal cord injury because of
preexisting degenerative vertebral disorders. Males are more prone to spinal
cord injuries than females but not as a result of preexisting disorder. This
may be related to an increased involvement in contact sports or a propensity to
participate in high risk activities. Neither females nor infants are at any
particular risk for spinal cord injuries.
Birds, insects, and many reptiles excrete nitrogenous waste in the form of uric acid, which saves water.
Nitrogenous waste in the body tend to form toxic ammonia, which must be excreted. Mammals such as human excrete urea, while birds, reptiles, and some terrestrial invertebrates produce uric acid as waste in the form of a white paste or power. The production of uric acid involves a complex metabolic pathway that is energetically costly in comparison to processing of other nitrogenous wastes such as urea or ammonia, it has the advantages of reducing water loss and, hence, reducing the need for water.
Answer:
it happens when 2 organisms jelp each other beneficial.
Explanation:
eg:algae and leguminous plants.the algae live on the roots and take in the nitrogen from the soil,which the plant cannot do and needs for growth.it takes in the nitrogen and pases it to the roots and even make the soil loose for the roots to move and they get a living space(algae on the roots).
This zone is called as the zone of aeration. It is present between the earth's surface and the water table, and its main constituents are the soil and rocks. The pores which are present in this zone are partly filled with water, and may mix up with air, causing aeration.
