Answer:
The first theories of matter were put forward by Empedocles in 450 BC, he proposed that all matter was composed of four elements - Earth, air, fire and water. Later, Leucippus and Democritus suggested matter was made up of tiny indestructible particles continuously moving in empty space.
Explanation:
Got it from google hope this help :))
Calcium because it is responsible for making our bones strong, thus allowing us to perform many activities.
According to simple diffusion. Molecules travel from high concentration to low. So it would be traveling into the cornea
Answer:
Progesterone is one of the female sex hormones which performs important function during menstrual cycle, pregnancy and embryo development.
During follicular phase, it helps in the ovulation while during luteal phase it plays an important function of preparing the endometrium lining of the uterus. In addition, it also inhibits or decreases the production of FSH and LH during this phase with the help of negative feedback mechanism.
Progesterone gives negative feedback to hypothalamus and anterior pituitary which decreases or inhibits the secretion of FSH and LH. It is important as it prevents the ovulation of second egg prior to fertilization.