For a muscle to contract in a cell, chemical reactions that involve a positive change in the amount of free energy available take place. Which of the following best describes the impact of these reactions in the cell? ( 2 points) They cause an increase in total entropy. They move the cell toward equilibrium. They occur spontaneously as they give off heat. They require energy to be absorbed to proceed.

What are the types of mutations, and how does each alter the encoded protein? college level answer

Female luna moths (actias luna) attract males by emitting chemical signals that spread through the air. a male hundreds of meters away can detect these molecules and fly toward their source. the sensory organs responsible for this behavior are the comblike antennae visible in the photograph shown here. each filament of an antenna is equipped with thousands of receptor cells that detect the sex attractant. based on what you learned in this chapter, propose a hypothesis to account for the ability of the male moth to detect a specific molecule in the presence of many other molecules in the air. what predictions does your hypothesis make? design an experiment to test one of these predictions.

Explain why it’s important for scientists to study the sun. list at least two challenges researchers face when examining earth’s nearest star.