Assuming that the statements are related to avian anatomy and physiology, analyze the following statements and choose the correct ones: 1- The fea...

Assuming that the statements are related to avian anatomy and physiology, analyze the following statements and choose the correct ones:

1- The feathers are only used for animal movement and can be extracted from chicks. F
2- The functions of feathers include skin protection, thermoregulation, camouflage, defense, courtship, recognition, and most importantly, they are essential structures for the flight of these animals. V
3- The contour feathers of the wings are called retrices and have primary and secondary feathers. The tail feathers, called remiges, are attached to the pygostyle and are used for direction and braking during flight. F
4- Many characteristics contribute to the lightness of the skeletal structure, such as a reduction in the number of bones, fusion of bones forming plates, modification of the thoracic limb into a wing, reduction in bone density, absence of internal bone matrix (pneumatic bones), and air sacs extending to the medullary cavity in larger bones. V
5- The gizzard or ventricle has the functions of assisting in protein digestion, as proteases were secreted in the proventriculus, and food grinding. V
6- The ceca in birds are paired structures that function in bacterial fermentation of cellulose through the action of bacteria and protozoa and enzymatic digestion by protease secretion. F
7- In the large intestine, the main function is the reabsorption of water and electrolytes by antiperistaltic movements. V
8- The cloaca is a common structure to the reproductive, urinary, and digestive systems. It is divided into coprodaeum, urodaeum, and proctodaeum by two partially complete annular folds. V
9- The bursa of Fabricius is located on the dorsal wall of the proctodaeum and is the site of production and differentiation of B lymphocytes. V
10- The renal portal system present in birds directs some blood coming from the pelvis and pelvic limbs directly to the kidneys before reaching the caudal vena cava. V
11- Unlike mammals, the respiratory system in birds does not have a diaphragm and is used for vocalization, thermoregulation, and effectively gas exchange. V
12- The syrinx, which is the sound-producing organ and responsible for hematosis in birds, can be classified as tracheal, tracheobronchial, or bronchial, depending on its location. F
13- The functional unit of the respiratory system is the alveoli, and in birds, they are responsible for hematosis, i.e., gas exchange (O2 and CO2). F
14- Gas exchange does not occur in the air sacs, as they are poorly vascularized. V
15- Birds need two breathing cycles to move a volume of air through their respiratory system. V
16- There is no urinary bladder or urethra in birds, and the nitrogenous compound eliminated, unlike mammals that excrete urea, is ammonia. F
17- The female reproductive system organs include the ovary and oviduct, and usually, only the left organs are functional, as the set in the right antimer regresses shortly after hatching. V
18- The isthmus is the cranial end of the oviduct, where fertilization occurs. The second part of the oviduct called the magnum is the longest segment and is responsible for producing albumin. The infundibulum is thinner, shorter, and takes an hour for the egg to pass through, where the shell membrane is formed. F
19- Biosafety is the adoption of a set of operational measures and procedures that aim to prevent, control, and limit the exposure of birds contained in a production system to disease-causing agents. V
20- Brazil has technical standards for registration, inspection, and control of commercial laying establishments, within the scope of the National Avian Health Program (PNSA) of the Ministry of Agriculture, Livestock, and Supply (Mapa). V
21- The aviary screening is mandatory and consists of placing screens on the doors and sides of the shed, and its main objective is to prevent the entry of insects and other animals that can transmit diseases. V
a) 1, 3, 6, 9, 12, 13, 19, 20
b) 2, 4, 5, 7, 8, 10, 11, 14, 15, 16, 17, 18, 21
c) 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21