Most of the time, when you plant seeds or grow from seeds the plants will have 100% of their genetic abilities. Usually, it will grow 100% asymmetrical with real distinctive characteristics on their leaves and stems, along with (usually) a higher yield and a better overall product as far as resin or turpine amounts. The older the plant gets, typically the less likely this asymmetry is going to keep happening.
For example: a plant you have been growing for six months started out with two leaves. Next, the plant grew three leaves, then five leaves, then the plants are growing little branches where each of these leaves are connected to the main stalk. Usually, until a plant is 2 foot tall or taller these plants will grow almost 100% asymmetrical. Branches will start to grow evenly, but plants will not grow 100% perfect. If one side of the plant is getting more wind and the other side of the plant is getting more light, the plant will stretch to grow towards the light and away from the wind.
This is just one typical thing that plants will do: grow towards their food source. Each of these leaves are little sugar generators that power the plant and give it the ability to grow and stretch and let its roots stretch to look for more water. Plants start growing asymmetrically because they have no clue which direction the wind is or the direction the sunlight is when they start growing. The seed just grows based on the gravitational pull of the earth.
Ever wonder how a little tiny seed planted an inch into soil knows to push his green leaves a certain direction out of the dirt? The gravity is pulling down so the seed tries to grow against gravity. Once it sees the light, the plant can start producing its own food and the taproot can start searching or growing feeder roots to search for nutrients and water.
The asymmetrical design of the plant and its structure is just based on its DNA structure to produce leaves and grow branches in certain places. These DNA structures actually allow you to manipulate the plant or cut it in a certain way to change the structure of the plant.
Topping is when you take a seed, let it grow to about 16 to 24 inches, and cut a section of the top of the plant off to force the plant now to start growing branches to search for more light (due to the fact they cannot grow straight up anymore). Usually plants, when topped, will start growing their branches asymmetrically. Once the forces of nature around them implicate their growing abilities, one or two branches might start growing a little faster than others. This is just natural.
Sometimes plants have a mind of their own. One Pheno that we grew in our gardens would sporadically grow two or four bladed fan leaves and sometimes would just grow deformed branches where every leaf on the branch would grow crooked and sideways with only two, three, or four blades per fan leaf.
Up top is a picture of a Poison Kush male in bloom from Pure Michigan Genetics. Notice the pollen satchels growing in groups like buds. I have the male far away from my females, notice the plywood grow box?