Plants
release oxygen into the atmosphere
release carbon dioxide into the atmosphere
use oxygen to create food and energy
don't rely on the atmosphere like animals do

Plants release oxygen into the atmosphere during the process of photosynthesis. In photosynthesis, plants make their food in the presence of sunlight. Water is extracted from the soil and carbondioxode enters through stomata and combine in the leaves of plants make glucose and oxygen. Glucose is stored in different parts of plant body and oxygen is released into the atmosphere which is used by living organisms.

answer; the tunica intima also called tunica interna, consists of elastic fibers,connective tissue and smooth muscle cells;