Growth of Plants: Shooting and Rooting!

My plants are currently around the stage called shoot and root. Meristem is a part of plant tissues which are in charge of growing roots and shoots in order for cells to divide and the plant to grow. In order for cells to divide, they need the hormone cytokinin which stimulates the division of cells for the growth of roots, shoots, and flowers. There are two types of growth:
1. Primary- Growth of the plant will exceed above and below ground. The shoot will appear when the tip of the stem is visible from the top of the soil. Growth will continue to occur upward, but not much more below. Roots on the other hand will travel downward into the soil and get hold of the ground in order to absorb nutrients for the shoot. It will grow straight downward and can grow out to the sides after its first shoot down. The hormone auxin is involved in both shooting and rooting which is in charge of plant elongation.
2. Secondary- The shoots will now begin to grow outward as well as upward. This can be seen in the image below. Gibberellins is the hormone responsible for plant growth upwards and outwards.

Vascular cambium is the think ring formed around the plant. On trees this is the bark which will scuff off very now and then.
Tropism is the movement of the plant depending on environmental factors. An example of this would be the plant facing towards the sunlight instead of away in order to absorb as much light as possible.