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.
A Twin by Any Other Name. A standard twin mattress is 39 inches wide and 75 inches long. Daybed, bunk bed or trundle bed mattresses in most cases are standard twin bed sizes. Some trundle bed frames come in full size as well; the mattress may be full or twin. If unsure, measure the mattress or frame. A twin or trundle mattress is not the same as a twin XL mattress, which is five inches longer and won't fit on a standard trundle or twin frame.