Answer:
Proteins serve many functions within an organism, such as mammals. Proteins are used to grow and repair tissues. ... Proteins also form hormones, which transport chemical messages between tissues and organs. Proteins are also important building blocks of bone, carilage, muscle, skin, and blood.
Link:
https://www.enotes.com/homework-help/outline-role-proteins-life-mammals-547196
Cephalization is the differentiation of end part of the body into a head in which nerve tissue is concentrated. Sponges have a very loose nervous system and their cells work individually, not controlled by a nervous system. Since they have no defined head as a consequence of concentrated nervous system, the sponges could not have cephalization either.
<h3>Global travel and spread of certain species</h3>
Explanation:
Many pathogenic species of bacteria, virus, and other microbes are more prevalent in developing or tropical countries rather than in developed countries.
When an individual’s immune system is weak they become more susceptible to get infected and become carriers of that particular species.
The species grows, develops, and multiplies in the host’s body and when the traveler travels to his/her home country or any other place he/she can transmit the disease to others and again the species grows in numbers. Higher the rate of spread of infection higher is the increase in species.
Melting because you can physically see it.