Seeds are the organs developed from the fertilized  ovules of plants. With the right conditions of water supply, temperature and location, they germinate to produce a new plant, thus beginning the next stage of the plant life cycle -- a cycle whose duration varies from species to species.

Making cuttings is a technique used for the  vegetative propagation of  plants. Some plants are able to produce (asexually) a new individual from a piece of root, stem or leaf when placed in a suitable medium. This is a kind of cloning because the cutting becomes a new plant with the same genes as its parent.

Sexual reproduction in plants  involves the formation of ovules and their fertilisation by pollen. The wind and water can be the vectors of this pollination but insects are the major actors in the process.

Unlike vegetative modes of reproduction, like cuttings, pollination assures that sexual reproduction will occur, which allows the mixing of genetic material, and so improves the probability of adapting to the environment.

The function of a flower is to produce seeds to ensure the continuance of the plant species.
The flower contains male parts (stamen) and female parts (pistil).
The bottom of the pistil contains the ovules and the top of the stamen produce the pollen grains.
They are usually enveloped by the calyx, formed by the sepals, and the corolla, formed by the (usually colored) petals.

Phytoremediation is the use of plants to clean up contaminated soil and water.

The pollutants can be stored in the plant (phytoextraction), volatized by the plant (phytovolatization) or  metabolized by plant derived-enzymes (phytodegradation).

The succesive stages of the plant cell mitosis are animated here: prophase, metaphase, telophase, anaphase and cytokinesis.