I believe it's stem cells.
Answer:
Gametes are an organism's reproductive cells. They are also referred to as sex cells. Female gametes are called ova or egg cells, and male gametes are called sperm. Gametes are haploid cells, and each cell carries only one copy of each chromosome. ... In contrast, each egg cell, or ovum, is relatively large and non-motile.
Explanation:
<h2>540 million years ago
</h2>
Paleozoic.
Era immediately follows Precambrian It lasted about 4.5 billion years.
When did abundant fossil evidence first appear in the geologic record.
540 million years ago.
Answer:
Natural selection occurs when some of those traits help some individuals survive and reproduce more than others. That causes their genes to become more common in the population over time, and it's the way species evolve to adapt to changes in their environment.
Explanation:
hope this helps =)