Long day plant

A long day plant is a plant that only grows after being exposed to light periods longer than certain critical lengths. For example summer lettuce.

Lichen

Lichen is a symbiotic collective formed by the mutualistic association between a fungus and a photosynthetic alga or cyanobacterium. Algae is an example of lichen.

Homeostasis

Homeostasis is a system to maintain internal stability. For example when a body is cold it shivers which I have pictured above is my little sister who is trying to achieve homeostasis. 

Gymnosperm lead

A gymnosperm leaf is the needles that produce the gymnosperm cone they are broad flat and pokey needles. They usually don't fall off in the winter. 

They are pictured above.

Gymnosperm cone

A gymnosperm cone is a plant whose seeds are not enclosed by a ripened ovary for example a pinecone