Does Natural selection or evolution involve with this? it sounds like spiders and other Insects or bugs that have evolved to be able to have limbs in order to survive in a environments that would require extra limbs. probably from genes being passed on and also being mutated positively in order for the newer species to better adapt. the pair of legs could have been increased because of the environment that requires it and also as the mating changes it's basically survival of the fittest.
Answer:
The correct answer is - Test cross.
Explanation:
A test cross is a cross that is made between an organism with an unknown dominant genotype and an organism that purebred recessive genotype for the particular trait. It determines if the unknown genotype of the individual being tested is purebred allele dominant or heterozygous for the trait.
If all offspring in F1 generation has phenotypically dominant trait then the tested organism is pure breed dominant and if half of the offsprings have the phenotypically dominant trait and half show recessive trait then the organism to be tested is heterozygous or hybrid.
The bacteria and algae get out of control and takes up all the oxygen