During photosynthesis, unused oxygen atoms from oxygen gas which is released as a waste product. how did these oxygen atoms orginally enter the plant

Photosynthesis defined as the process by which plants make there own food by trapping sunlight and using carbon-dioxide and water to produce glucose as energy.

During photosynthesis oxygen is formed as raw material along with glucose after utilizing carbon-dioxide and water.

Photosynthesis process take place in two stages light-dependent and light-independent process. During the light-dependent reactions,  water molecule releases an electron and oxygen and hydrogen atoms gets free. The free oxygen atom combines with another free oxygen atom and forms diatomic oxygen (O2) that released to atmosphere.

This is how oxygen enters the plants with the help of water molecules.

answer; atp and nadph;

the corpus luteum secretes estrogens and progesterone. the latter hormone causes changes in the uterus that make it more suitable for implantation of the fertilized ovum and the nourishment of the embryo. if the egg is not fertilized, the corpus luteum becomes inactive after 10–14 days, and menstruation occurs.

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