They make up everything needed to create DNA, although im not very sure, i think the answer your looking for is DNA.
<span>Gametophyte stage is the stage in the life cycle of the plants where the changes happen in the generations which are basically a sexual phase in the plant's life. So the haploid Gametophyte stage produces gametes (eggs and sperm) by mitosis. The spores produced from the meiosis grow into gametophyte which goes through mitosis to attain the above mentioned alterations.</span>
The physical need to eat food is called hunger