Final answer:
The number of genes in plants varies, but some, like Arabidopsis thaliana, have about 27,000 genes, which is slightly more than the average number found in humans.
Step-by-step explanation:
The number of genes in plants can vary widely among different species. In comparison to humans, who have an estimated 20,000 to 25,000 genes, some plant species may have a similar number of genes or even more. For instance, Arabidopsis thaliana, a widely studied model organism and a small flowering plant in the mustard family, has its genome completely sequenced and is known to possess about 27,000 genes. This is slightly more than the average number of human genes. It is important to note that the number of genes is not directly correlated with organism complexity and that plants can also have extensive non-coding DNA which might not necessarily be involved in coding for proteins but can have regulatory functions or be involved in the structural organization of chromosomes.