The pollen grains contain sperm which will fertilize the egg and create a seed to sprout the next generation of plants. The main male part is the stamen. It is divided into two parts: the anther and the filament. The anther produces the pollen grains that contain the sperm needed for fertilization.
The first known single-celled organisms appeared on Earth about 3.5 billion years ago, roughly a billion years after Earth formed. More complex forms of life took longer to evolve, with the first multicellular animals not appearing until about 600 million years ago.
<span>specialized cells, thats what bone and blood cells are considered </span>
