<u>Answer</u>: The answers are matched as follows:
African forests have been hunted to near extinction levels to obtain ivory-------------->human exploitation
The eruption of mount Saint Helens destroyed some populations of conifers------> natural disasters
An infection with a fungus reduced the population of North American Elm trees ----> disease
Increasing global temperatures have altered migration patterns of humpback whales ------>climate change
<u>Explanation</u>:
- <em>Human</em> <em>exploitation</em> is the unethical or selfish use of resources to satisfy their own personal needs or for any profitable activity which harms the resources in such a way that they get limited. Humans have been hunting elephants to obtain ivory for many purposes such as making jewellery etc. and earning profits from it. Due to such extensive hunting they have driven the elephants to a level of extinction and thus, this is a form of human exploitation.
- Mount Saint Helens is a volcano and its eruption which harms the population of the trees in the area is a form of natural disaster since volcanic eruption is a <em>natural</em> <em>phenomena</em>.
- Fungal infection is a <em>disease</em> which is cause by the microorganisms which harms the population of the Elm trees.
- Increase of global temperature is a type of climate <em>change</em> and thus, this effect of alteration of migration pattern is caused by climate change.
Answer:
True
Explanation:
The species that went extinct could be a food source for another and that would possibly be detrimental to the chain.
Answer:
option B) The oxygen end of the molecule has a partial negative charge and the hydrogen end has a partial positive charge.
Justification:
The electronegativity of an element accounts for its relative ability to attract electrons.
Being oxygen more electronegative than hdyrogen (the electronegativity of oxygen is 3.44 while the electronegativity of the hydrogen is 2.20), the electron density will be displaced toward the oxygen, letting it with a partial negative charge and the hydrogen with a partial positive charge.
Finally, since the charge is not symmetrical distributed around a center of the molecule, the molecule ends being polar.