A certain species of butterfly varies in color from white to dark blue. The birds found in the same area feed on the white or li
ghtly colored butterflies, leaving butterflies that are darkly colored. This may result in what type of selection? (a) disruptive selection
(b) stabilizing selection
(c) directional selection
Directional selection is a type of natural selection that occurs when members of a population of a species with a particular extreme phenotype is selected or favored against the other phenotypes when natural forces act on the population of a species. Individuals having the particular traits that are favored survive and become more common that others with traits that are less favored.
Directional selection may likely result in the species of butterflies in which darkly collared butterflies are not preyed upon, ensuring their survival, while the other butterflies with other colors will be phased out with time. Darkly colored butterfly will be selected for while the others will be selected against.
When oestrogen rises to a high enough level it causes a surge in LH from the pituitary which causes ovulation where an egg is released from the follicle (Day 14 of the cycle). The follicle becomes the corpus luteum and this produces oestrogen and progesterone which inhibit FSH and LH production by the pituitary.
