In a comparison of birds and mammals, having four appendages is <span>a shared ancestral character</span>
The right answer is the promoter.
• The promoter is a nucleotide sequence that allows the transcription of the gene into mRNA. It is recognized by the RNA polymerase that initiates transcription. During the synthesis of the RNA, the promoter indicates which gene must be expressed and therefore which proteins the cell must produce. In an operon it is common to all genes.
• The operator is a segment of DNA and / or messenger RNA to which a chemical signal (a regulatory molecule) binds. It can be either a repressor signal or a transcription activating signal (DNA operator) or translation (RNA operator) of the genes of the operon. The RNA polymerase does not recognize this structure.
I think the answer is d because the bodys first line of defense is both physical and chemical barriers ect. skin, tears, mucus, cilia, stomach acid and urine flow
Cephalocaudal pattern of motor development
Answer:
The water and polar residues cannot bind to the hydrophobic ones, so in the lowest energy state the hydrophobic residues are pushed together in the middle.
