<span>Microevolution refers to changes in the genetic pool
of a species population. The changes in the genes (probably gene and allele frequencies)
are observed over short time periods hence are small changes. This is in comparison
to macroevolution that observes huge changes over longer time periods in the population that warrant that the new populations
is considered to be a new species</span>
Igneous rocks are formed when the magma from an erupting volcano eventually cools this rock is extrusive- found on the earth's surface.
Answer:
DNA
Explanation:
Thymine is one of the four nucleobases that pairs with adenine to make up DNA, also called 5-methyluracil. It is replaced by uracil to make RNA molecules during transcription.
Theferore the unknown chemical analyzed was DNA because thymine is found in DNA and not in RNA molecules.
Answer:
The answer to the given question is C.
Explanation:
Natural selection:
The population contains both superior as well as inferior organisms where natural resources are limiting so it will cause competition between organisms. As a result of competition, it will select superiors, and inferiors are deleted and they are given reproductive advantages. Due to this reproductive advantage new population emerges. It is more suitable for the environment.
Natural selection divides into three parts that are directional, disruptive, and stabilizing selection.
This is an example of natural selection. Environmental conditions create pressure on the individuals and if they can survive and become fittest, their number increases in the population. This is according to Darwin's theory in the struggle for existence. These organisms survived as the fittest organisms to match climatic conditions.
Stabilizing selection: This operates when features coincide with the optimal environmental conditions and the organisms survive in a population. Stabilizing selection pressures do not promote evolutionary change but tend to maintain stability within the population from generation to generation.
In the beginning, directional selection - the organism develops characters to survive in response to gradual changes in the environmental conditions. It works on a range of phenotypes existing within a population and exerts selection pressure which moves the mean phenotype to one phenotypic extreme. When the mean phenotype overlaps with the new optimum environmental conditions, stabilizing selection will take over.
