Tag: photosynthetic pigments

Chlorophyll absorbs sunlight of particular wavelength that causes spitting of water at water splitting complex of photosystem II and oxygen gas is released. PSI absorbs light below 680nm while PS II is activated by light below 700 nm; so plants exhibit maximum amount of oxygen released when illuminated with simultaneous exposure to red and far red light. Fixation of $CO _2$ occurs during the dark reaction. Thus, the correct answer is B.

Total amount of dry weight of photosynthate produced by all type of plants per annum is 170000 million tonnes. There are several factors, which limit the formation of dry weight such as reduced nitrogen fixation which will result in reduction of dry weight.

Blue green algae are prokaryotic orgnanisms and lack membrane bound organelles. Mitochondria and cholroplast are double membrane bound organelles of eukaryotes that serve as site of aerobic respiration and photosynthesis respectively. Chromatophores are the pigment containing membranous structures that serve as site for photosynthesis in BGA. Correct answer is A.

• Thylakoid (internal photosynthetic membranes) is a membrane-bound compartment present within the cellular organelle called chloroplast, they are also present in cyanobacteria.
  
• It is a site for the light-dependent reactions of photosynthesis. 
• It is made up of a thylakoid membrane which surrounds the thylakoid lumen.
• The term thylakoid was coined by Menke in the year 1962.
  
• So, the correct answer is 'Menke'.

Intact chloroplast from green leaves can be isolated by the acetone isolation method. The membranes of the chloroplast are proteinaceous in nature so it can be easily isolated by acetone. The samples obtained are loaded to the chromatography apparatus, which shows bands on the chromatogram.

So, the correct option is B. 

The chloroplasts are double membrane-bound organelle that is found in the cytoplasm. They have membrane-bound thylakoids in which the photosynthesis takes place. The cytoplasm is thus separated from the intrathylakoid space by 3 membranes. i.e the 2 membranes of the chloroplast, and some membrane of thylakoid.

• A stack of thylakoid discs is organized to form grana.
  
• A thylakoid refers to the membrane-bound internal compartment within the chloroplasts of a plant cell and cyanobacteria.
  
• It is a site for light-dependent reactions of photosynthesis. 
  
• There are about  10 to 100 thylakoid discs within a granum and about 40- 60 grana in a plant cell.
  
• So, the correct answer is 'Stacks of thylakoids'.

• Ulothrix is a genus of filamentous green algae which are found in marine and fresh waters habitats.
  
• They have a single girdle-shaped or band-shaped chloroplast near the peripheral region of the cytoplasm (near the cell wall).
  
• So, the correct answer is 'Girdle-shaped'.