Which factor best explains why classification systems change over time? changing environments lead to reclassification.

1.changes in food sources lead to reclassification.

2.increased plant species leads to reclassification.

3.increased knowledge of genetics leads to reclassification.

4.increased knowledge of genetics leads to reclassification.

i think 1. but not sure.

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.

Areal dna molecule consists of thousands of these pairs of nucleotides. what is the pairing arrangement of the nitrogen bases

9. the history of life on earth is recorded in