Answer:
In order to propose a hypothesis, there is a need to first see the function of gills in fishes. The gills of fishes comprise blood vessels that exhibit inherited tendencies of getting oxygen out of the water, which was consumed by fishes from their mouths. These gills also comprise thin walls, and when water moves over these walls of blood vessels, the oxygen from water moves into the blood, and then this oxygen-enriched blood goes to various organs.
Thus, one of the hypotheses in the given case, can be the number of blood vessels, which are found in the gills of the mentioned freshwater fish to be higher in comparison to the blood vessels found in the normal fishes, and apart from this, the surface area of the thin walls, which are found in the gills is also more in the new species of freshwater fish.
A single species that has evolved into several different forms that live in different ways has undergone "b. convergent evolution" since the multiple "divergent" species are seen to "converge" into a single species if you go back far enough in time.
Spread of disease is density dependent because it is more severe the greater the population density as the disease would spread more easily. If there is low population density it would spread slower.
Answer:
chloroplasts
Explanation:
photosynthesis takes place inside plant cells in small things called chloroplasts ( mostly found in the mesophyll layer) contain a green substance called chlorophyll
Because the earth is moving around the sun but the sun isn’t revolving around anything
