The lac operon, which stands for Lactose operon is known as an inducible system. It is the an operon required for the transport and metabolism of lactose some enteric bacteria (Echerichia coli for example). The Lac operon is only activated in the presence of a key molecule. The key molecule is lactose.
From the given options the following best describes the Lac operon:
D. The repressor is freed from the operator when lactose is present.
Answer:
The correct answer is - photosystem II; ATP; water; oxygen
Explanation:
The photosynthesis process involves two different cycles known as the light reaction and the dark reaction. In light reaction there are two photosystems; photosystem I and photosystem II.
During light reaction, there are several pigments such as chlorophyll a and other pigments present in photosystem II that trap the light and transfer excited electrons through ETC to produce ATP which is a form of energy used by cells.
A water molecule takes place of the excited electron that is transferred and releases oxygen as waste or byproduct in this reaction.