Why do lysosomes keep their digestive enzymes in membranous sacs?
A. because the membranous sacs can sense when the cell is about
to be attacked
B. because the membranous sacs keep the digestive enzymes
from destroying the cell
C. because the membranous sacs act as tails that help the
lysosomes move faster
D. because the membranous sacs act as factories helping the
digestive enzymes make proteins

they fuse to form they have half as many chromosomes as a somatic cell of the same individual. b

step 1: initiation

initiation is the beginning of transcription. it occurs when the enzyme rna polymerase binds to a region of a gene called the promoter. this signals the dna to unwind so the enzyme can ‘‘read’’ the bases in one of the dna strands. the enzyme is now ready to make a strand of mrna with a complementary sequence of bases.

step 2: elongation

elongation is the addition of nucleotides to the mrna strand. rna polymerase reads the unwound dna strand and builds the mrna molecule, using complementary base pairs. there is a brief time during this process when the newly formed rna is bound to the unwound dna. during this process, an adenine (a) in the dna binds to an uracil (u) in the rna.

step 3: termination

termination is the ending of transcription, and occurs when rna polymerase crosses a stop (termination) sequence in the gene. the mrna strand is complete, and it detaches from dna.