A HOX gene called Pax6 is required for developing light sensing eyes (or eye-like structures) in a range of Phyla including Cnidaria, Mollusca, Arthropoda, and Chordata. Humans (Chordata) and squid (Mollusca) have complex eyes with many shared features, like a lens, that are NOT found other Phyla that have eyes or eye-like structures. a. Are the human eye lens and the squid eye lens most likely homologous or analogous structures? Briefly explain your reasoning. (2 points) b. If you could examine the DNA of a "lens formation" gene in a squid and in a human, what evidence would support your reasoning? (2 points)

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.

oxygen +1 most likely

bacterium is not correct

the growth of the plants is affected by the heat of the light. what is the student doing?