I have never heard of the four phases of research, but I know that the scientific method can be summarized in four steps.
1. Observe something in nature.
2. Make a hypothesis (prediction) based on that observation.
3. Design and undergo and experiment to test the validity of your hypothesis.
4. Draw a conclusion about your hypothesis based on the results of your experiment.
Answer:
The correct answer is: a. Maggots do not arise spontaneously, but from eggs laid by adult flies.
Explanation:
- The meat in the open jars can be directly accessed by the adult flies for consumption. While accessing the food, some of these adult flies can lay egg into the jars which hatch to give rise to new maggots.
- The meat in jars closed by a gauze is exposed to the air but cannot be accessed by the adult flies as the flies are prevented from entering into the jar due to the presence of the gauze. As a result of this the flies do not consume meat, nor do they lay eggs and so no maggots will appear in this jar.
Chromatin during interphase is in it's most loosely condensed state and is spread through-out the nucleus
The endosymbiotic theory states that the some cellular organelles present inside the Eukaryotic cells were once free-living prokaryotic organisms. The eukaryotic cells ingested these organisms and over time they developed a symbiotic relationship with each other. These organelles include the mitochondria and the chloroplasts. Both these organelles contain their own DNA, and produce energy.
Hence, the answer is 'mitochondria and chloroplasts'.