Answer:
Natural selection causes change in allele frequencies within a population.
So option A is correct one.
Explanation:
Natural selection generally work on an organism’s phenotype, or observable features. Phenotype is often largely a product of genotype (the alleles, or gene versions, the organism carries). When a phenotype produced by certain alleles helps organisms survive and reproduce better than their peers, natural selection can increase the frequency of the helpful alleles from one generation to the next – that is, it can cause microevolution.
Answer;
-A motor protein called dynein
Cilia and flagella bend because of a motor protein called dynein.
Explanation;
-Both prokaryotic and eukaryotic cells contain structures known as cilia and flagella. These extensions from the cell surface aid in cell movement. They also help to move substances around cells and direct the flow of substances along tracts.
-Cilia and flagella are formed from specialized groupings of microtubules called basal bodies. If the protrusions are short and numerous they are termed cilia. If they are longer and less numerous they are termed flagella.
A food web does not represent all the links in an actual ecosystem.
Explanation:
A food web is also called food cycle. It is understood by the natural interconnection of chain and their graphical representation. The concept is given by Charles Elton. He mentioned about the concept of food cycles in Animal Ecology but later this food cycle is replaced by food web.
Food web are limited representation of eco system. Ecologists can keep together all life forms broadly into one of the two categories which is called tropic levels. These two categories are autotrophs and heterotrophs
