HORTICULTURE

Detailed explanation-1: -Photosystem I occurs before photosystem II during the light reactions. a collection of pigments that trap solar energy and focus it on reaction centers, releasing high-energy electrons.

Detailed explanation-2: -There are two types of photosystems in the light-dependent reactions, photosystem II (PSII) and photosystem I (PSI). PSII comes first in the path of electron flow, but it is named as second because it was discovered after PSI.

Detailed explanation-3: -Photosystem I and photosystem II are the two multi-protein complexes that contain the pigments necessary to harvest photons and use light energy to catalyse the primary photosynthetic endergonic reactions producing high energy compounds.

Detailed explanation-4: -In light reactions of photosynthesis, photosystem II occurs before photosystem I because the process of photosystem II is the very first process in the chain to perform photosynthesis.

Detailed explanation-5: -Photosystem I comes before photosystem II in the noncyclic electron pathway. Photosynthesis and cellular respiration utilize the same chemical pathways but in reverse of each other. Photosynthesis and Only organisms with chloroplasts are capable of photosynthesis.