The correct answer is dynamo theory. The theory that explains the source of Earth's magnetic field is the dynamo theory. This theory proposes the mechanism of a celestial body such as Earth to generate magnetic field.
B and C)
They often obtain most of their nutrients through the cell membrane as diffusion is able to take place passively and so at no energy loss to the organism, this can be essential for a single celled organism as they are able to produce a lot less energy due to having fewer mitochondria in comparison to multicellular organisms.
They also require few resources as single celled organisms are very small and so require only a small amount of raw resources for respiration because they have a small energy demand to meet.
Answer:
H
Explanation:
H is the dominant allele while h is recessive.
The correct asnwer to your question - why would a group of antelopes leave the herd for search of a better grassland is an example of emigration - B.
These antelopes would emigrate to a certain grassland and be immigrants in that grassland. This has to be distinguished.