Zoology Test - 2

Heloderma is the genus containing the Gila monster and Mexican beaded lizard, the only venomous lizards in the world. They produce neurotoxic venom in glands in their lower jaws and deliver it through grooved teeth.

Wharton's duct is the main excretory duct of the submandibular salivary gland, located on the floor of the mouth beneath the tongue. It drains saliva from the submandibular gland into the oral cavity.

Colleterial glands in female cockroaches secrete proteins that form the ootheca - the protective egg case. The ootheca hardens to protect the developing eggs and is deposited in sheltered locations.

Arteriosclerosis is the thickening and hardening of arterial walls due to loss of elasticity. An aneurysm is a weakened bulging area, not thickening, and arthritis is joint inflammation unrelated to arteries.

Neuromasts are the specialized sensory cells found in the pits and canals of the lateral line system in fishes. They detect water movement and vibrations, helping fish navigate, avoid obstacles, and detect prey.

The intestinal lining has a brush border composed of microvilli that massively increase surface area for nutrient absorption. It is neither ciliated nor keratinized - those features would impair absorptive function.

Glycosidic bonds are the covalent bonds linking sugar molecules in carbohydrates like starch. During carbohydrate digestion, enzymes break these glycosidic bonds to release simple sugars. Proteins and lipids have different bond types.

Blood type O individuals have both anti-A and anti-B antibodies in their plasma because they lack A and B antigens on their red blood cells. Type AB has neither antibody, type A has anti-B, and type B has anti-A.

Gout is caused by elevated levels of uric acid in the blood, which can crystallize in joints causing intense pain. Urea is a normal waste product, and cholesterol is unrelated to gout pathology.

Preganglionic sympathetic fibers release acetylcholine at their synapses with postganglionic neurons, making them cholinergic. This is true for all autonomic preganglionic fibers regardless of whether they are sympathetic or parasympathetic.

In insects, the alary muscles are wing-like muscles associated with the heart that help expand the heart chamber during diastole. These muscles are crucial for facilitating hemolymph flow through the dorsal vessel and are unique to the insect circulatory system.

Pancreatic juice contains high concentrations of bicarbonate ions (HCO3-) which neutralize the acidic chyme entering from the stomach. This creates the optimal alkaline pH needed for pancreatic enzymes to function properly in digestion.

Chaga's disease (Chagas disease) is caused by the protozoan parasite Trypanosoma cruzi, transmitted by triatomine bugs (kissing bugs). Trypanosoma gambiense causes African sleeping sickness, while the spelling 'trypanosoma bruci' appears to be a misspelling of Trypanosoma brucei.

Goblet cells are merocrine glands because they secrete mucus through exocytosis without losing any cellular material. Merocrine secretion is the most common type, where secretory vesicles fuse with the plasma membrane and release their contents. Holocrine glands lose entire cells, apocrine glands lose portions of the cytoplasm.

Hydrolysis is the universal chemical process in digestion, where water molecules are used to break down complex molecules (proteins, carbohydrates, fats) into simpler units. Condensation is the opposite process (building up), phosphorylation adds phosphate groups, and emulsification is specific to fat breakdown.

All three muscles - semitendinosus, semimembranosus, and biceps femoris - are hamstrings located on the posterior thigh. They all flex the leg at the knee joint, extend the thigh at the hip joint, and contribute to adduction (especially semitendinosus and semimembranosus).

Septicemia is the presence of bacteria or their toxins in the bloodstream, commonly referred to as blood poisoning. It is a serious systemic infection that can lead to sepsis and septic shock. It is not food poisoning (which is gastrointestinal) or a mental disorder.

The P wave in an ECG represents the depolarization of atrial muscle tissue, which is the electrical event that precedes atrial contraction. Option A incorrectly states it represents contraction itself - the ECG records electrical activity, not mechanical contraction. The QRS complex represents ventricular depolarization.

Acetylcholinesterase is the enzyme that rapidly breaks down acetylcholine at synaptic clefts and neuromuscular junctions, terminating its action. This is crucial for proper nerve signaling and muscle function. Acetylcoenzyme-A is involved in metabolism, Acetylcysteine is a mucolytic drug, and Acetyltransferase transfers acetyl groups.

The pulmonary circulation is powered by the right atrium (which receives deoxygenated blood from the body) and the right ventricle (which pumps this blood to the lungs). The left atrium and ventricle handle systemic circulation. Both chambers work together to power pulmonary flow.

The dartos tunic is a layer of smooth muscle in the scrotal wall that contracts in cold conditions to regulate testicular temperature, helping maintain optimal conditions for sperm production. It is not found in the uterine, urethral, or abdominal walls.

The detrusor muscle is the smooth muscle layer of the urinary bladder wall. During micturition (urination), it contracts to increase intra-bladder pressure and expel urine forcefully through the urethra. Latissimus dorsi and hamstrings are skeletal muscles unrelated to bladder function.

The morula stage of embryonic development is enclosed by the zona pellucida, a glycoprotein layer surrounding the oocyte and early embryo. The corona radiata is an outer layer of follicular cells that disperses during fertilization and is not present around the morula stage.