According to the given information, an individual carries one allele for blood group A antigen and one allele for the blood group B. Let's assume that the allele I^A imparts blood type "A" while the allele I^B is responsible for blood type B. Now, the genotype of the individual is I^AI^B and its phenotype is blood type "AB".
When both the alleles of a gene are expressed in a heterozygote and the phenotype of the heterozygote is distinct from both the pure breeding parents, the pattern of inheritance is called codominance. The I^A and I^B alleles codominant as both are equally expressed in the heterozygote.
The theory of evolution that states that groups of organisms change over time. In essence, a current population of kangaroos is a product of several changes that have occurred over millions of years, resulting in the kangaroos we currently see.He's perhaps the most famous evolutionary scientist. He published his theory of evolution by natural selection in 1859
Darwin knew a mechanism was behind the change, or evolution, that had occurred, creating different beaks. He called this mechanism natural selection. Darwin proposed that over time, a population of finches could develop different beak shapes in order to best eat whatever food was most available to them, thus allowing them to survive better
He used the term 'survival of the fittest' as a short hand for organisms so well-suited to their environment that they will live long enough to reproduce, passing their traits, like beak shape or eye color, to the next generation
Hence, the right answer is "Organisms within a population vary, and all populations produce more offspring than can be supported by the environment, resulting in competition for survival within the population"