Ethylene
Ethylene is a hydrocarbon chemical emitted from most
fruits that promotes ripening. When fruits are bunched together this
creates more ethylene and thus ripens each fruit faster. The more fruits
are bunched together, the more ethylene is produced and the faster all
the fruits ripen - this is why sometimes the fruits at the bottom of a
carton are much riper than at the top, because they are soaked in
ethylene.
When parallel rays of light pass through a convex lens the refracted rays converge at one point called the principal focus. The distance between the principal focus and the centre of the lens is called the focal length.
Answer:
Variations are caused by mutation. random mating between organisms.
Explanation:
The thermosphere keeps the earth from geting to hot frome the sun and it's the last layer so...the thermospher
