3. which of the following occurred before the cambrian explosion?

4. the simplest animals to have body symmetry are?

5. look at figure 26-1. the cladogram suggests that the cambrian explosion most likely took place after the development of which characteristic?

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.

What causes eclipses? check all that apply. earth's rotation on its axis moon's shadow covering the sun earth's shadow covering the moon earth's orbit and moon's orbit occasionally aligning the moon and sun's gravity pulling in the same direction

Abody cell has been growing and at synthesis proteins. in the nucleus of this body cell, dna replication is taking place. and a copy of the cells genetic material is copied. which of the following is the best conclusion you can make about the life cycle of this cell ? a) the cell is ready to undergo mitosis. and a chemical signal will send the cell to prophase b)the cell is undergoing meiosis and will cross over the genetic material next c)the cell is in the s phase of interphase and will move next to the g2 phase d) the cell is in the g2 phase of the interphase and is ready to begin diving