Which observation do most scientists think supports the big bang theory as a description of the origin of the universe? a. our sun is a yellow star. b. the universe appears to be expanding. c. stars that vary in luminosity exist. d. stars change their positions in the sky.

An organ system consists of a group of organs that performs specific functions necessary for the survival of an organism. humans have eleven different organ systems: integumentary, skeletal, muscular, nervous, endocrine, circulatory, lymphatic, respiratory, digestive, urinary, and reproductive. discuss the function of neurons, the brain and the spinal cord within the human nervous system while explaining the interrelationship of each organ.

In the presence of oxygen, glycolysis is followed a. the krebs cycle b. lactic acid fermentation c. alcoholic fermentation d. photosynthesis

The smallest parts of these that retain their original properties are called