Tag: control and coordination in living organisms

When contraction of the uterus starts, oxytocin is released, which stimulates more contractions and more oxytocin is released. In this way, contractions increase in intensity and frequency. Oxytocin causes contractions during the second and third stages of labor.

Pheromones are chemicals released by an organism into its environment enabling it to communicate with other members of its own species. It changes the behaviour of another animal of the same species (animals include insects). 

Formic acid is the simplest carboxylic acid and occurs naturally, mostly in ant venom. 

The corpus luteum is a temporary endocrine structure in female mammals, that is involved in the production of progesterone and moderate levels of estradiol and inhibin. The corpus luteum develops from an ovarian follicle during the luteal phase of the menstrual cycle or oestrous cycle, following the release of a secondary oocyte from the follicle during ovulation. 

Luteinizing hormone (LH) stimulates the production of sex hormones by gonads. Since LH acts on gonads, it is known as gonadotropic hormones.  

Gynaecomastia refers to the presence of enlarged mammary glands in males like that of females and is caused by the presence of extra X chromosome in males. Gonochorism is the unisexual condition. Feminization refers to the development of female secondary sexual characters caused by hormonal changes at puberty in females. So, the correct answer is option D.

ADH secretion is regulated by plasma osmolality. If osmolality increases it stimulates secretion of ADH which act at the collecting duct of nephron where it causes the reabsorption of only water and produces the concentrated urine.

Progesterone is produced from the corpus luteum, which is the small gland, that forms in the ovary after ovulation has occurred. This hormone is essential for the maintenance of pregnancy and also for the development of many symptoms during early pregnancy.

Vasopressin, also known as antidiuretic hormone (ADH), is a neurohypophysial hormone which has two primary functions- to retain water in the body and to constrict the blood vessels. Vasopressin regulates the body's retention of water by increasing water reabsorption in the collecting ducts of the kidney nephron.

Prolactin (PRL), also known as luteotropic hormone or luteotropin, is a protein, that in humans is best known for its role in enabling female mammals to produce milk. Prolactin is a single-chain protein hormone. It is secreted by the lactotrophs in the anterior pituitary (adenohypophysis).