Answer to Question 1
Answer: Ultraviolet light (UV) is in the range of frequencies that resonate with atoms and molecules in the glass. At resonance, the amplitudes of vibration are very large and atoms and molecules hold onto UV energy for millions of vibrations, during which time the energy is passed to neighboring atoms by many collisions. The transmitted energy takes the form of thermal energy instead of light. So although glass is transparent to visible light, it isn't to UV.
Answer to Question 2
Answer: According to the model of light presented in the text, when a photon is incident on a glass surface it is absorbed by a glass molecule or atom and forced into vibration. This vibration results in the emission of an indistinguishable photon, which travels to the next atom or molecule to repeat the process. A cascading process of absorption and reemission occurs until the glass molecule at the far surface absorbs and reemits an identical photon.
Phytochrome controls germination by responding to red/far red light signals.
A light-coloured cane toad
Mosaic glass bowl, fused and slumped, Roman.
What Are You Pouring in Your Glass?
Light-independent reactions in C4 plants
Animated Light-independent reactions in CAM plants.