What evidence do vestigial organs provide to support the idea that life changes over time?

a. these organs likely had a function in an ancestral organism but no longer appear to have a purpose in the modern descendant organism

b. these organs scientists classify related species, even after they have drastically changed over time.

c. these organs likely never had a function but may take on an important function in the future of the species.

d. these organs had one purpose in an ancestor of the species and have adapted over time to serve a new purpose in the descendant species.

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.

1. efficient use of space

2. elimination of groundwater contamination

3. energy generation

4. lower carbon footprint