Answer:
The answer is natural selection
Explanation:
Ans.
Lac (lactose) operon in a type of bacterial operon, which shows a cluster of genes that are regulated by a single promoter. It is composed of an operator, promoter, a terminator, and three structural genes (lacA, lacY, and lacZ), which are responsible for the transport and breakdown of lactose.
The lac operon is an inducible operon as it gets activated in the presence of lactose and expressed its functional genes in the form of proteins (or enzymes) for lactose metabolism.
Thus, the correct answer to be fill in first blank is 'inducible' and in second blank is 'lactose.'
I think the organisms are compared to each other.
Answer:
a. parasitism:
The parasite benefits by harming the host e.g hookworms and humans
b. commensalism
In this association, one species benefits while the other is unaffected (its not harm and dies not benefit) e.g. epiphytic orchids and trees
c. mutualism
Here, both species benefit as seen in rumen bacteria and cows
Explanation:
Parasitism = +/- relationship
The predator benefits by harming the host. E.g. hookworms and humans. The hookworm (parasite) eat man blood while man (host) loses blood to it.
Commensalism = +/0 relationship
One specie(s) benefits while the other specie(s) neither benefits nor is harmed. E.g. epiphytic orchids live on tree branches or tree trunks as it's habitat or shelter while the trees neither benefits nor is harmed
Mutualism = +/+ relationship
Both organisms benefit in this relationship. E.g. rumen microbes aids grass digestion in cows, while the microbes benefit as it obtain steady food or nutrient from the cow
