The source of all energy in the pyramid in model one is the hawk
The decline in the overall population of trout and larger fish is because the Insect population has decreased.
<h3>What is a population?</h3>
A population is a group of organisms of the same species living in the same habitat.
Population of organisms is affected by;
- availability of water
- space
- food and nutrients
- predators
- climate change
Since the population of trout is directly affected by the number of insect species, the decline in the overall population is because the Insect population has decreased.
Learn more about population at: brainly.com/question/746835
Answer: Option C
Secretion hormone stimulates the release of pancreatic fluid.
Explanation:
Secretion is a digestive hormone secreted by the duodenum(upper part of small intestine) that stimulates the release pancreas fluid and regulates the water homeostasis thought out the body and around duodenum. Its also regulates pancreas, liver and stomach secretions.
Answer : A metal in group 16 of the periodic table can become a chemically stable ion by gaining 2 electrons.
Explanation :
The group 16 element are oxygen, sulfur, selenium, tellurium and polonium.
The general electronic configuration of group 16 elements is, 
As we now that there are total 6 electrons in p sub-shell. So, a metal in group 16 can become a chemically stable ion by gaining 2 electrons.

Hence, a metal in group 16 of the periodic table can become a chemically stable ion by gaining 2 electrons.