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.
How Big Is a Double Bed? The double mattress, or full mattress, actually provides less room per person than a twin mattress. In the U.S., a double mattress is 54 inches wide and 75 inches long, according to the consumer website Mattress Sizes. Jupiterimages/Photos.com/Getty Images. According to the website of The Better Sleep Council, double mattresses are only big enough for one adult. Standard twin mattresses are 39 inches wide and 75 inches long, according to Mattress Sizes. If a double mattress is shared, it provides only 27 inches of space per person.