Answer:
Due to presence of these structures in ancient as well as modern organisms.
Explanation:
Homologous and vestigial structures are the evidences that show evolutionary relationships between organisms because these structure were also present in the ancient ancestor of that organism. These homologous and vestigial structures shows the relationship between the ancient and the modern organisms. Some structure has a purpose and function in the body of ancient organisms but with the passage of time those structure are useless and have no function in the body but these structure shows connection between modern and ancient organisms.
A 5-carbon base, C,A,G,T are the 5 bases available
Answer:
A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea.
Answer:
Negatively repressible.
Explanation:
A control which occurs through repressor is known as negative control which may be inducible or repressible.
When a small molecule named as allolactose binds this repressor it leads to allosteric repulsion which removes repressor from the operator as a result of which RNA polymerase can start transcription. Allolactose is therefore known as inducer because it induces lac operon expression.
But here, the operator is active (induced) already so there is no need to induce the operon which means that it can only be repressed so that transcription could stop. So the answer is negatively repressible operon.
