Photosynthesis in Plants

Maximum number of chloroplast in the leaf is found in palisade tissue.

Oxygen is a by-product of photosynthesis and not a reactant, so photosynthesis can take place in the absence of oxygen. So, option 1 is correct.

The phloem transports products of photosynthesis from the leaves where they are synthesised to other parts of the plant. 

Chloroplast contains green coloured pigment called chlorophyll that helps in the process of photosynthesis.

 Leucoplast is a special type of plastid present in the plants for storage of starch, oil and proteins.

Chlorophyll is the primary photosynthetic pigment in plants, giving leaves their characteristic green color. It absorbs red and blue wavelengths of light for photosynthesis while reflecting green light, which is what our eyes perceive.

It is the last electron acceptor and reduces the enzyme NADP+ reductase.

In plants such as wheat, rice, gram and mustard the plants die after seed production. This is also observed in monocarpic plants which live for several years but flower only once in their life time as in sago palm and bamboos.

Plants produce carbohydrates through photosynthesis, converting light energy, water, and carbon dioxide into glucose and other carbohydrate molecules. This makes plants the primary producers of carbohydrates in virtually all ecosystems, forming the base of food chains. Marine animals, coal tar, and crude oil either consume carbohydrates or are derived from ancient plant matter, but only plants actively synthesize carbohydrates from inorganic sources.

Leucoplasts are primarily organelles in which materials such as starch, oils and protein granules are stored. Lysosomes help in removing dead and worn out cellular organelles (cell debris) by digesting them.

Chlorophyll carries out 3 types of reactions during photosynthesis: 1) Photoionization (chlorophyll absorbs light and loses an electron), 2) Electron transport (passing excited electrons through the electron transport chain), and 3) Photophosphorylation (ATP synthesis using the proton gradient created). These are the light-dependent reactions.

The light-independent reactions (Calvin Cycle) occur in the stroma of the chloroplast. The stroma is the fluid-filled space surrounding the thylakoids. Thylakoids are where the light-dependent reactions occur. Leaves contain chloroplasts but are not the specific site of the Calvin Cycle.

Photolysis (the light-induced splitting of water molecules) occurs during the second phase of the light-dependent reactions in photosynthesis. During the first phase, chlorophyll absorbs light and gets excited. In the second phase, the excited electrons are replaced by splitting water (photolysis), releasing oxygen and providing electrons to continue the process.

Photolysis is the light-driven decomposition of water molecules into hydrogen and oxygen, a key process in photosynthesis where light energy breaks the chemical bonds in water.

Two large green hemispherical structures which enclose the embryonic axis are called as the cotyledons. The cotyledons may be one or two in number depending on the type of plant. The cotyledons are important becausetheyt give nutrients during the early development of the plant before starting the process of photosynthesis.