Depend if you are more creative or more a solver(good in math).
Answer:
1. Parasitism
2. Mutualism
3. Competition
4. Commensalism
Explanation:
The given are all different ecological relationships. These relationships how the members of the ecosystem interact with each other.
Parasitism is a relationship where one organism is harmed and the other one benefits. However, parasitism is specifically referring to a relationship where one lives inside the other organism, causing it harm by directly feeding off them or depriving it from getting nutrients.
Mutualism is a relationship were both organisms benefit from the relationship. In the example, the aphids provide protection for the ants while the ants provide food to the aphids (honey dew). Another example of a mutualistic relationship would be the tickbird and the rhino. The rhino benefits because the tickbird eats the ticks of the rhino, and in return, the tickbird is fed.
Competition is a relationship between organisms that compete for resources. In the case of your question the two grasses are competing against each other for the nutrients and water. Animals also share this type of relationship, especially when those that prey on the same animals for food.
Commensalism is a relationship between organisms where one benefits and the other does not benefit, but is NOT harmed. A good example would be the remora and sharks. Remoras are fish that swim with sharks. They swim beneath the sharks fins. The sharks provides them protection from other predators and remoras benefit because they get to eat scraps of the sharks food as well.
Answer:
B. Use the polymerase chain reaction (PCR) to make multiple copies of the DNA.
Explanation:
The scientist is to analyze a small sample of DNA, the most useful step to start this would be first the use of polymerase chain reaction to make various copies of that DNA sample. PCR is essential and quick process that gives a lot of copies within few hours. It uses the sample or target DNA, according to which the primers are designed. Taq polymerase and DNA polymerase are also used in the process, it consist of various cycles in which copies are made. There are three basic steps 'Denaturation', 'annealing', and 'extension'.