how does growth occur at the buds, down the twigs, and throughout the stem?

Answer 1

Apical meristem is responsible for primary root and stem growth in vascular plants.

Primary Root Growth: is concentrated near the tip and results in the root growing in length. The root tip contains 4 zones of development: The root cap, which protects the area behind it and softens the soil ahead of it by producing a polysaccharide. The apical meristem, is an area of rapidly dividing cells. It will replace the cells of the root cap as they wear away and push cells above them that will develop into the main tissues of the plant. The zone of elongation, is an area where the cells elongate 10 times their original length. This elongation helps push the root into the soil. The zone of maturation, is the area farthest from the root tip. Here the new cells will specialize and carry out the functions of the epidermal, ground, and vascular tissue. The primary tissues in a dicot root are arranges in a central x pattern for the xylem with the phloem located in each of the angles of the xylem. In a monocot the vascular tissues are alternated in a circle.
Primary Stem Growth: begins at the tip of the terminal bud in the area called the apical meristem. The cell divisions are responsible for the stem's growth in length. The primary vascular tissue in monocots takes on a scattered arrangement. In a dicot, it takes a circular pattern.

Secondary Growth: Increases the girth of a stem it is caused by the vascular and cork cambium.

Vascular Cambium: meristematic parenchyma produces xylem on the inside and phloem on its outer side. The secondary xylem accumulates and forms the wood. The secondary phloem does not accumulate and is sloughed off with the bark.
Cork Cambium: forms in the outer cortex. Produces cork and epidermal tissues.
Wood has 2 zones: Heartwood- the older (inner) layers of xylem blocked with resins. It is non -functional in water transport. Sap wood- outer xylem, vascular cambium, phloem and cork cambium. Conducts water and food.

Answer 2

Thumbs down to wikipedia cut and pasters. Again, you could at least try to summarize the information to actually answer the question. Or at least paste the link so you aren't completely guilty of plagarism.

Trees have meristematic tissue, just like all other plants. The twigs have apical meristems and axillary meristems that generate the buds. The increase in twig and branch diameter (width) is due to meristematic tissue in the vascular cambium.

Answer 3

Meristem: Early dividing tissue present in tips of roots and shoots, and along stem, in the form of cork cambium and vascular tissue (phloem and xylem).

The apical meristem (roots and shoots) accounts for vertical growth (height), and the axial meristem (stem) accounts for the horizontal growth (thickness).

Another thumbs down for wikipasters. Please don't waste peoples time. If you don't know, a cut-and-paste doesn't do anything except make you look like a points whore. It's not like you're winning any prizes here buddy, he's trying to find an answer to his question!

Answer 4

Apical meristems at the tips of the shoots elongate the shoots - this is known as primary growth. Secondary growth is responsible for increases in girth and does not occur in all plants (it occurs at the vascular cambium).

Answer 5

Auxins are a class of plant growth substance (often called phytohormones or plant hormones). Auxins play an essential role in coordination of many growth and behavioral processes in the plant life cycle

Location of Auxins
* In shoot (and root) meristematic tissue
* In young leaves
* In mature leaves in very tiny amounts
* In mature root cells in even smaller amounts
* Transported throughout the plant more prominently downward from the shoot apices

Growth and division of plant cells together result in growth of tissue, and specific tissue growth contributes to the development of plant organs. Growth of cells contributes to the plant's size, but uneven localized growth produces bending, turning and directionalization of organs- for example, stems turning toward light sources (phototropism), roots growing in response to gravity (gravitropism), and other tropisms.

As auxins contribute to organ shaping, they are also fundamentally required for proper development of the plant itself. Without hormonal regulation and organization, plants would be merely proliferating heaps of similar cells. Auxin employment begins in the embryo of the plant, where directional distribution of auxin ushers in subsequent growth and development of primary growth poles, then forms buds of future organs. Throughout the plant's life, auxin helps the plant maintain the polarity of growth and recognize where it has its branches (or any organ) connected.