Which statement about electric and magnetic fields is ture? A) Electric fields must leave a positive charge and end on a negative charge. B) Electric fields and magnetic fields start at a positive and end at a negative. C) Magnetic fields must start at the North pole of a magnet and end at the south pole of a magnet. D) Electric fields and magnetic fields loop from north to south.

Researchers randomly divide participants into groups. each group takes a different amount of omega-3 fatty acid supplements daily for a month. one group receives a placebo. the researchers measure the impact on cholesterol levels in the blood. what is the purpose of random assignment in this experiment? a, to produce treatment groups with similar characteristics b, to ensure that all people with high cholesterol have an equal chance of being selected for the study c, to increase the accuracy of the research results and prevent skewness in the data

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.

Sexual reproduction in the parent cell will result in offspring with a) identical genetic information. b) half the genetic information. c) double the genetic information. d) four times the genetic information.