Dendrochronologist
<span>Dendrochronology (or tree-ring dating) is the scientific method of dating <span>tree rings.</span></span>
Answer:
True
Explanation:
The deep parts of an ocean receive minimal or no sunlight. Hence, the survival of phototropic organisms like plants and algae is impossible or minimal here. Hence, there is a very little diversity in deep oceans. The organisms living here have to feed on dead decaying matter or on each other for survival. Mostly, the organisms living here use dead organisms as food. No other food source is available here.
<u>Answer:</u> A single covalent bond is present between the carbon atoms.
<u>Explanation:</u>
Carbon is the 6th element of the periodic table. The electronic configuration of this element is: 
This element has 4 valence electrons and to attain stability, it cannot gain 4 electrons nor it can loose 4 electrons. Thus, it has to share 4 electrons in order to attain stability. Thus, this element forms covalent bond.
A covalent bond is formed by the sharing of electrons between two atoms.
In the question, it is given that carbon is bonded to 2 hydrogen atoms and two carbon atoms. Thus, the bond between the carbon atoms will be a single covalent bond.
Answer:
Decrease
Explanation:
It will decrease because fish need a certain amount of oxygen to live, but when chemicals from fertilizers or detergents enter the habitat, the oxygen decreases.