Explanation:
Rust is the term we use to describe red iron oxides produced when ferrous metals corrode. Rust is the common name for the chemicals that result when iron reacts with oxygen and water. “Rust” is poorly defined in chemistry, however—lots of chemicals can be formed when iron is left exposed.
Answer:
The environmental factor that could lead to a decrease in genetic variation in a tuna population is an increase in pollution (second option).
Explanation:
There is a correlation between genetic variability and environmental pollution, the latter being a factor that impacts negatively on the variability of a specific population.
The concept of pollution stress not only implies a low rate of reproduction, but it is also a factor that prevents genetic exchange with other populations, which is a factor that makes the genetic variability decrease in a population.
For these reasons an increase in pollution implies a decrease in genetic variability in a tuna population.
- <em>Other options, such as </em><u><em>an increase in food availability</em></u><em>, a</em><u><em> decrease in tuna fishing
</em></u><em> or </em><u><em>a decrease in tuna predators</em></u><em>, are environmental factors that contribute to increased genetic variability.</em>
This is an example of passive immunity. Immunity to a disease is achieved through the presence of antibodies to that disease in a person's system. For example measles antibody will protect a person who is exposed to measles disease, but will have no effect if they are exposed to another disease. There are two types of immunity, namely; passive and active' Active immunity results when exposure to a disease triggers the immune system to produce antibodies to that disease. Passive immunity is provided when a person is given antibodies to a disease rather than producing them through his or her own immune system.
