<span>Fossil record, genetics, and examples of local adaptations all support the theory of evolution by natural selection.</span>
Answer:
Tetrahedron Structure The chemical structure of silica forms a tetrahedron. It consists of a central silicon atom surrounded by four oxygen atoms, with which the central atom bonds. The geometric figure drawn around this arrangement has four sides, each side being an equilateral triangle—a tetrahedron.
Explanation:
.....estrogen and progesterone are low
In women, menstrual flow occurs
as a result of the actions of some hormone between the pituitary gland in the
brain and the ovaries. Female sex hormones prepare the body for fertilization
every month and without fertilization there is menstrual flow. Menstruation is activated
by reduced levels of the hormones estrogen and progesterone at the end of the
previous menstrual flow.
For instance, the pansy butterflies and gold finches both are yellow and black in color. The butterfly and goldfinch also fly and have wings. However, the butterfly has no beak, no feathers, whereas, the gold finch has a beak and feathers, but no antennae.
