Answer:
Rats - Virgin Island
Hemlock - Asia
Zebra moulds - Great Lakes
Explanation:
An alien species is one that was introduced into a new environment, but does not have harmful effects. Such alien species are considered invasive species as they begin to have harmful effects on the new habitat. Invasive species can cause damage to the ecosystem, economic harm or human health effects.
Three invasive species are as following:
- Rats that came on board ships to the Virgin Islands infested the islands' sugar cane fields and caused significant crop damage.
- The woolly adelgid hemlock is an invasive Asian insect which rapidly kills infested hemlock trees.
- Zebra moulds in the Great Lakes can easily cover submerged surfaces, obstructing water intakes at water treatment plants and power plants
Answer:
A. True
Explanation:
Hemoglobin is a protein and has two distinct types of polypeptide chains. These are called the alpha and beta subunits. The gene that code for the beta chain undergoes a mutation in a single base that causes sickle cell anemia. Here, adenine base in the genetic code for glutamic acid is substituted with a thymine base.
The genetic code for glutamic acid in the beta chain gene is GAG. The "A" is replaced with "T" and the new code "GTG" codes for valine. Therefore, the mutated hemoglobin has valine in place of glutamic acid. This makes these mutated protein molecules to form aggregates resulting in a change in the shape of RBCs carrying them.
