what do we call the chemical substances necessary for an organism to sustain life A. energies B. nutrients C. supplements

B. nutrients

Explanation:

Nutrients are chemicals present in all living things on Earth. They are essential for the lives of humans, plants, animals ,and all other species. Nutrients help remove food that provides energy to the species. Carbon, hydrogen and oxygen are the most essential nutrients which they need.

Hence, option B is correct as it is necessary for sustain the life of an organism

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.