Which tissues function to primary growth and secondary growth
Primary growth is the increase in length of the plant body. Apical meristems that are found at the tips of roots and shoots are responsible for primary growth. The tissues involved in primary growth are:
1. Apical Meristem - responsible for cell division and new growth.
2. Shoot and Root Tips - where the apical meristem is located in order to cause elongation.
3. Axillary Buds - a meristematic area found at the base of leaf axils that can form new branches.
Secondary growth is the increase in width or girth of the plant body. Secondary growth occurs in stems and roots of woody plants, and is responsible for producing the annual growth rings of trees. The tissue involved in secondary growth are:
1. Vascular cambium - a layer of meristematic cells that produces secondary xylem to the inside of its ring and secondary phloem to the outside of its ring.
2. Cork cambium - a layer of meristematic cells that produces cork cells that form a protective layer called bark.
3. Secondary xylem and phloem - produced by vascular cambium, secondary xylem provides wood and is the source of growth rings, while secondary phloem carries nutrients throughout the plant.