Hormones are chemical substances that help to regulate processes in the body. Hormones are secreted by glands and travel to their target organs in the bloodstream. Hormones can be used to control human fertility.
The Cambrian explosion was a period at the Pre-Cambrian boundary of the geologic time scale at 542 Ma. At this boundary, the fossil record shows that animals suddenly appeared in a dramatic radiation of life. A radiation is the relatively rapid development of new types of organisms that derive from a common ancestor. The Cambrian explosion is important because it marks the origination of all major animal groups called phyla.
Yes, Organisms compete for the resources they need to survive like food, air, water, space. In areas where these are sufficient, organisms live in comfortable co-existence, and in areas where resources are abundant, the ecosystem boasts high species richness (diversity).
Answer:
1. Essential organs form during early development
Explanation:
Harmful chemicals (toxins) cause the most disease when they are present during fetal development, because organ systems are being developed and the rate of growth is very fast.
