I) steroid hormones are lipid soluble and easily cross the phospholipid bilayer. ii) steroid hormones usually exert their effects on target cells through membrane receptor proteins. iii) steroid hormones act on cells close to where they were produced. iv) steroid hormones regulate gene transcription by binding to intracellular receptor proteins.

After reading the paragraph below, answer the questions that follow. researchers have created a robot that has a very thin leg that is moved by cardiac (heart) cells contracting in unison. the robot, made of a polymer similar to that used in making contact lenses, is bathed in heart cells with supporting cells, which then attach to the robot and provide movement as they contract. all of the cardiac cells working together can cause the robot leg to move in a way that individual cells could not. this is an example of a. emergent properties of cells. b. energy flow through an ecosystem. c. adaptation. d. internal environment regulation.

I’m doing some practice exam questions for biology, and i’m not sure how to do these 3 parts to the question.

Which organisms have pharyngeal arches that develop from all three germ layers and go through the same development stages as embryos? 1.bird 2.ladybug 3.starfish 4.snake