You yearn for something when you really, really want to have it. The lizard in the picture is yearning for the freedom of being outside.
You yell when you shout loudly. People often yell out to get someone's attention, or because they are hurt.
Scientific name: taxus baccata
The yew tree is a kind of conifer originally from parts of Europe, Africa, Iran and Asia. It is a small to medium, slow-growing tree, reaching around 10 to 20 metres high. The leaves and seeds of the tree are very bitter and poisonous. The yew's pine cones are unusual, being more like a berry with a single seed. The berries are eaten by some kinds of birds.