In terms of organisms, photosynthesis occurs in autotrophes that contain the green pigment chlorophyll. This would include the entire plant kingdom, half of the Protista (the algae), & half the Moneran Kingdom (the blue-green algae).
A standard twin mattress is 39 by 75 inches. A king is 76 by 80 inches. This means that a headboard for a king bed is going to be about 76 inches or wider, plenty wide enough to go along the length of a twin bed. Headboards are often slightly wider than the bed for which they are made.
King size mattress dimensions are approximately 76 inches wide by 80 inches long, making a king mattress almost the same size as two twin XL beds. This bed size is also preferable if you have children, dogs or cats that will be sharing your bed. twin size mattress is the smallest mattress available and is best suited for one child or one adult. The dimensions of a twin size mattress are approximately 39 inches wide by 74 inches long. Taller adults may be more comfortably sleeping on a twin XL bed size.