In humans, red blood cells are the only cells that eject their nuclei as they develop. By emptying themselves of nuclei, these cells are able to do which of the following?
replace themselves quickly when more cells are needed
transport greater amounts of oxygen and waste throughout the body
transmit electrical impulses quickly
attack bacterial pathogens more effectively

Which of the following statements best describes the relationship between the environment and human health? a. the environment is the only factor that affects human health. b. many aspects of the environment can have an impact on human health. c. human health is impacted by changes in climate. d. the environment has no impact on human health. select the best answer from the choices provided

Many animals cannot sweat to maintain a stable body temperature. what is one other way animals can cool down?

Which chemical equation is unbalanced? which chemical equation is unbalanced