Answer:
It helps the cactus live a long time between rainstorms.
Explanation:
A thick, waxy coating keeps the water inside the cactus from evaporating.
Answer:a. Retention of five functional digits on the tore and hindimbs
Explanation:
The presence of five digits or pentadactyly on the fingers as well as on the toes makes the primates distinct from other mammals. Also the keratin nails are present on each digit makes these organisms distinct from other mammals.
The five digits on the hindlimbs helps in grip of objects and on toes helps in climbing.
Salinity refers to an increase in the dissolved salt content of a body of water. Salinity has great impacts on the type of organisms that live inside the water. In the question given above, the salinity occurs as a result of non natural influence; since most of the organisms living inside the water before probably have specific optimal salinity range, if the salinity exceed the range they can cope with, they will probably migrate away from the water, those that refuse to migrate will probably die out and new species which can cope with the salinity level will emerge.
Most mammals including humans are endothermic. Reptiles and amphibians are ectothermic.
Human evolution known to be a process in which species adapt to certain conditions of life, and in the battle of life and death, they are forced to become stronger in order to survive in this world. Diseases have always been present during the evolution, acting themselves as a natural selectors - the weaker organisms get sick and die. Not just humans, but all species have to establish a great protecting mechanism in order to survive. That is how our bodies are built, to be able to withstand and survive in the conditions we live in, and that is why our immune system has to be taken care of.