The nucleus, this is for Eukaryotic cells.
Answer:
a. a portion of the population becomes isolated from the remainder of the population and experiences different selective pressures
Explanation:
This is an example of allopatric speciation Allopatric speciation is a form of speciation (formation of new species) that occurs as a result of geographic isolation. This means that a part of population becomes physically separated from the initial main population. There is no gene flow between these two populations and as a result the two populations reach a high level of genetic divergence. They can no longer interbreed which means they become two different species (speciation).
New populations evolve as result of mutation, genetic drift and natural selection.
For example, Galapagos finches are isolated from others by the ocean (geographic isolation). Because of the isolation, the finches don’t breed with one another. So, they developed unique characteristics and became endemic.
Out of the following given choices;
A. theory that fish and mammals have a common ancestry
B. theory that the first organisms on Earth were heterotrophs
C. close relationship between fish and mammalian reproductive patterns
D. close relationship between humans and annelids
The answer is A. Many embryos of the kingdom Animalia share similarities in the early stages depicting that they share a common ancestor. The gill slits is one example. They diverge in later stages to become Pharyngeal in the human embryo, while they differentiate into gills in fish.
