Describe 2 types of global change that are of concern to biologists.

In many humans, exposing the skin to sunlight over prolonged periods of time results in the production of more pigment by the skin cells (tanning). this change in skin color provides evidence that -

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

Abird flies by moving its wings up and down. which two systems are most directly responsible for the movement of a bird's wings? a. skeletal and muscular systems b. respiratory and muscular systems c. skeletal and digestive systems d. respiratory and digestive systems