The gene for the beta chain of normal human hemoglobin has the sequence CTC at the position for the seventh amino acid in the protein. A point mutation changing the sequence to CAC results in sickle cell hemoglobin. Use the genetic code to determine the change in the amino acid at position seven of the hemoglobin beta chain.1. glutamic acid to histidine2. glutamine to histidine3. glutamic acid to leucine4. glutamic acid to valine

The function of the excretory system is to control homeostasis and

The cretaceous period spanned the time interval between and 65 million years ago. 250 million 144 million 75 million 200 million

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