Hello. Giraffes with longer necks survive compared to those with shorter necks because of natural selection. Over time, natural selection favors the traits that would make a species thrive better in the environment. Giraffes with short necks won't have access to that much food compared to those with long necks thus they eventually died out.
The principal characteristic that differentiates temperate and tropical rain-forests is <u>latitude.</u>
There are two types of rain-forests, namely, the tropical rain-forests and the temperate rain-forests. These two types share some similarities such as being rich in plant and animals species with a greater diversity in tropical rain forest.
However they differ in a number of ways; tropical rain-forests are warm and moist; while temperate rain-forests are cool.
<u><em>Tropical rain-forest, forested areas must: Lie between the Tropic of Cancer and the Tropic of Capricorn, receive rainfall regularly throughout the year, remain frost and free through out the year with little fluctuations.</em></u>
<span>Allow deletion of DNA loops for recombination. Complementary sequences of RSS form H-bonds, RAG-1 and RAG-2 hold the pieces together, V(D)J recombinase cuts out loop of DNA, ends are ligated together with junctional and insertional flexibility.</span>