Suppose that scientists also studied a second population of belding’s ground squirrels from a different habitat. life table data for the first three years of this hypothetical population are shown below. (note that the table is not completely filled in because you will be calculating some of these values.) age (years) number alive at start of year proportion alive at start of year death rate average number of female offspring 0-1 80 1.000 0.00 1-2 64 ? 1.20 2-3 40 2.40 which equation determines the proportion of ground squirrels alive at the start of year 1-2? (this value is marked with a "? " in the table.) 40/64 = 0.625 (80-64)/80 = 0.200 64/80 = 0.800 (80-64)/64 = 0.250

Proteins are the workhorses of the cell, controlling virtually every reaction within as well as providing structure and serving as signals to other cells. proteins are long chains of  amino acids  , and the exact sequence of the amino acids determines the final structure and function of the protein. instructions for that sequence are encoded in  genes  . to make a particular protein, a messenger ribonucleic acid (mrna) copy is made from the gene (in the process called  transcription  ), and the mrna is transported to the  ribosome  . protein synthesis, also called  translation  , begins when the two ribosomal subunits link onto the mrna. this step, called initiation, is followed by elongation, in which successive amino acids are added to the growing chain, brought in by transfer rnas (trnas). in this step, the ribosome reads the  nucleotides  of mrna three by three, in units called  codons  , and matches each to three nucleotides on the trna, called the anticodon. finally, during termination, the ribosome unbinds from the mrna, and the  amino acid  chain goes on to be processed and folded to make the final, functional protein