Answer:
Answer:
e. Nutrient runoff from agriculture fertilizers, manure, and urban sources, which leads to rapid algal growth and subsequent bacterial decomposition
Answer:
Explanation:
Run off from agricultural wastes which contain Nitrogen and Phosphorus are the major sources causes dead zones.The process where these chemical get washed into the aquatic bodies is called Eutrophication.
These substances leads to algae boosts in the water.The increases population of the algae consumes the available oxygen in the water, therefore making the oxygen concentration drops or no oxygen at all;(Hypoxia)
As the algae population feed on the available resources in the water they exhausted this,and later die.
When the decomposing bacteria used the oxygen in the water to breakdown the dead algae they make use of the available oxygen.This further reduced the oxygen availability and therefore reduces the oxygen and hence the zone becomes the dead zone, because little or no oxygen is available for survival of organisms.
This is reversible if the process if europhication or other causes is eliminated
Explanation:
Explanation:
3 examples would be touch, light and chemical.
and the most common signal would be chemical.
Hope this helps! (:
Answer:
They showed how organic molecules could be made from Earth's early atmosphere.
Explanation:
Miller-Urey experiments were based on the ides of a-bio-genesis. It means the production of life through the non biological factors. In this experiment it shows that life can be produced through chemicals and molecules that were found in the early form of earth and is composition.
It kind of gives off to the evolution theory and the amino acids which are the building blocks of life and were given rise to during the simulation.
Answer:
Explanation:
The population density of an area is a demographic tool used to measure the number of organisms or individuals in a particular area.
It is expressed as;
Population density = 
The unit is expressed as organisms/km²
An area with a high population density is often not desirable as it can lead to pressure on amenities and infrastructure.
Because they contain CARBON
