Answer:
Certain fossils, called index fossils, help geologists match rock layers. To be useful as an index fossil, a fossil must be widely distributed and represent a type of organism that existed for a brief time period. Index fossils are useful because they tell the relative ages of the rock layers in which they occur.
<span>1.<span>Understanding life. Primarily, studying biology gives you the essentials
and primal knowledge of life and how and what you can perceive from it, may it
be various fields of zoology, botany or anthropology, psychology, sociology and
etc. It lets you understand the different anatomies, physiologies and
behaviours on how they act independently, interact and influence one another. </span></span>
<span>2.Protecting life. It provides a sense of preserving life as your upmost
goal in studying biology. You came to an actualization to delve into this science
as to be a steward and a developer.</span>
<span>
3.Responsibility. It comes with ethics. You become concerned with how
actions of a certain populace of a species can affect the entire ecosystem.
Human behavior has massive effects to the biosphere.</span>
<span>4.Advancement. The improvement and enhancement on how we can preserve and
understand life and the human populace develop and utilize the earth without
damaging its vital components.</span>
<span>5.Involve in the current issues and participate. You can be part of a
responsible scientist and individual, a citizen of science to stop and help grow
the serious concerns of today’s abusive human behaviours and life-threating concerns.</span>
<span>In marine vertebrates, the gill arches use the external gas exchange. The water holds less oxygen.
The ribs in terrestrial vertebrates have enclosed respiratory surface which is inside the body and comes as paired lungs.
Kidneys are efficient in excretion of regulation of water and nitrogenous wastes. Their reproduction is normally sexual with separate sexes.</span>
Answer:
The coastal upwelling and changes in wind and water circulation patterns is the main natural cause of dead zones.
Fertilizers cause hypoxia due to the over growth of algae on the surface of water bodies.
Explanation:
Coastal upwelling is the cause of dead zones in which water that is present in depth comes to the surface of ocean due to the movement of water because of wind. Fertilizers cause hypoxia due to the over growth of algae on the surface of water bodies. The fertilizers increases the algal growth by providing nutrients necessary for its growth. This over growth decreases oxygen concentration in water and affect marine organisms.
