Which was Charles Darwin's contribution to the study of biology? - He was the first person to recognize that organisms change over time.

- He believed that organisms adapted through the inheritance of acquired traits.

-He explained how traits are passed from parents to offspring.

- He proposed that natural selection is the primary mechanism of evolution.

Achemical that is released by an animal as a signal to other members of the same species is called a pheromone. t or f

Embryonic stem cells are cells derived from an embryo. these cells can be used to create new tissues for patients suffering from certain illnesses and disorders. which statement best summarizes why the use of embryonic stem cells could be seen as unethical? a. some people consider embryos to possess rights equal to those of fully developed human beings. b. extracting stem cells from embryos is a very energy-intensive process, which consumes resources that could be used elsewhere. c. embryos are difficult to obtain, so the monetary cost of using them for research outweighs their benefit. d. the process of extracting stem cells from embryos generates biohazardous waste that cannot be safely disposed of.

Does solar energy ever run out? brainliest