A scientist is searching for chemical compounds involved in embryonic limb development. She discovers a new compound that is transiently (briefly) expressed in the limb and only seems to affect cells in its immediate vicinity (up to a few cell lengths away). How should the scientist classify this chemical compound?

a. as a neurotransmitter
b. as a paracrine factor
c. as a peptide hormone
d. as a steroid hormone

The condition in which joints are inflamed is bursitis select the best answer from the choices provided ot f

What advantage does a crop that undergoes vegetative reproduction have over plants that start from the seed? 1points a they store nutrients. b they can travel farther. c they experience more genetic variation. d they only occur in high-resource environments.

Hydrilla (hydrilla verticillata) is an invasive aquatic plant and one of the most serious aquatic pests in florida. hydrilla has already been introduced to hundreds of bodies of water throughout florida, hydrilla is difficult to control because it grows rapidly and survives in many different water depths and conditions. hydrilla • describe how hydrilla affects native plant and animal species. include both a biotic and an abiotic limiting factor. • suggest one biotic and one abiotic recommendation that could slow the spread of hydrilla