What are some biotic and abiotic limiting factors of the population of frogs

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.

Idont understand by supporting the plant and holding the leaves up to the light. question 3 options: tap or fibrous root flower petals herbaceous or wood stems leaves with stomata

The negative change found inside the plasma membrane is created by potassium ions sodium ions hydrogen ions chlorine ions