If the sperm cell fertilises the ovum, and implantation does not occur, then the corpus luteum degenerates and it turns into corpus albicans, stopping progesterone secretion. If fertilisation occurs and implantation also, the syncytiotrophoblast, the "root part" of the blastocyst (one of the early structures originated from the zygote), produces a hormone that is called <span>human chorionic gonadotropin (hCG). The hCG is what makes the corpus luteum keep secreting progesterone and maintain itself. The progesterone will then help keep the endometrium and, therefore, allow the development of the embryo to happen.</span>
Answer;
-Papule
Explanation;
A papule is an area of abnormal skin tissue that is less than 1 centimeter around. A papule has distinct borders, and it can appear in a variety of shapes. Papules are often called skin lesions, which are essentially changes in the color or texture of your skin.
-Papules and pustules are the result of an increase in oil and bacteria trapped inside the pore by dead skin cells. Papules occur when the clogging causes a hair follicle to become inflamed. When this happens, the body's immune system sends white blood cells to fight the infection.
size hence streams are little and rivers are bigger than streams because a stream connects between two or more rivers
mark brainliest please :)
The main difference between the organisms are the uses of the appendage and the size and number of certain bones. The human arm is used for a variety of functions while the lizard's and the cat's are used for walking an climbing, the whale's for swimming, the frog's for support and the bird's and the bat's for flying.
