This type of natural selection is referred to as directional selection. In this type of natural selection, either one phenotype is preferred or the other; therefore, there is no equilibrium between the populations of the phenotypes that are present.
Examples of organisms that have undergone directional selection are black bears during the ice ages, African chichlid and sockey salmon.
Alveoli are found in lungs and exchamge O2 and Co2 !!
so answer is last one !!
In meiosis I, homologous chromosomes separate, while in meiosis II, sister chromatids separate. Meiosis II produces 4 haploid daughter cells, whereas meiosis I produces 2 diploid daughter cells. Genetic recombination (crossing over) only occurs in meiosis I. D
The affinity of hemoglobin for oxygen is less than its structural analog myoglobin. However, this does not affect hemoglobin's usefulness for the body; on the contrary, it allows hemoglobin to be a more efficient carrier than myoglobin. This is because hemoglobin can release oxygen more easily than can myoglobin. It is both important for oxygen to be carried to different areas and also to be released when needed. The higher affinity of a given protein for oxygen, the harder it will be for that protein to release oxygen when needed. Therefore, hemoglobin's lower affinity for oxygen serves it well because it allows hemoglobin to release oxygen more easily in the body.
