Zoology Test - 1

T8 cells refer to T lymphocytes that express the CD8 co-receptor, which are known as cytotoxic T cells. These cells are responsible for killing virus-infected cells, tumor cells, and damaged cells. T4 cells (CD4+) are helper T cells.

All three diseases are related to the lymphatic system. Hodgkin's disease is a cancer of the lymphatic system (lymphoma). Multiple myeloma is a cancer of plasma cells (which are derived from B lymphocytes in the lymphatic system). Chronic lymphocytic leukemia is a cancer of B lymphocytes.

Hodgkin's disease (Hodgkin lymphoma) is a cancer of the lymphatic system that specifically affects lymphocytes, which are a type of white blood cell. It does not primarily involve erythrocytes (red blood cells) or all leucocytes.

Alpha waves (8-13 Hz) are present during relaxed wakefulness and disappear entirely during sleep. Beta waves (alert wakefulness) decrease but don't completely disappear. Theta and delta waves actually appear or increase during various stages of sleep.

Honey has a very high sugar concentration (about 80% sugars like fructose and glucose). This creates a solution with extremely high osmotic pressure. When bacteria are exposed to this, water is drawn out of the bacterial cells by osmosis, causing them to become dehydrated and die, preventing decay.

The right cerebral hemisphere is primarily responsible for face recognition and processing visual patterns. The left hemisphere is more involved in language and analytical processing. Face recognition is part of the right hemisphere's specialization for visuospatial processing.

In arachnids like scorpions, the prosoma (also called cephalothorax) is the anterior body tagma that results from the fusion of the head and thorax segments. The abdomen remains a separate posterior tagma (opisthosoma).

Ferritin is the primary iron-storing protein in animals, plants, and bacteria. It stores iron in a soluble, non-toxic form. Alpha globulins and gamma globulins are blood proteins involved in other functions (like transport and immunity). Albumins are transport proteins.

Pituitary nanism (dwarfism) is caused by hyposecretion (underproduction) of somatotrophic hormone (growth hormone, GH) from the anterior pituitary gland. ACTH affects adrenal cortex function, not growth.

Red tide is caused by dinoflagellates (like Karenia brevis), which are microscopic algae that can reproduce rapidly and produce harmful toxins that color the water red. They are neither protozoans, corals, nor all of the above.

When body cells are infected with viruses, they produce interferon - a group of signaling proteins that interfere with viral replication. Interferons trigger immune responses and help protect neighboring cells from infection. Properdin is part of complement system, gamma globulins are antibodies, and hybridoma is a laboratory-produced cell hybrid.

Vertebrate bones are primarily composed of calcium phosphate in the form of hydroxyapatite crystals, which provides hardness and rigidity. Calcium carbonate is the main component of invertebrate shells like those of mollusks. Sodium chloride and potassium hydroxide are not structural components of bone tissue.

Taste buds are exteroreceptors because they detect external stimuli from the environment (food). Interoreceptors detect internal body conditions like blood pressure or pH. Teloreceptors detect distant stimuli like vision and hearing, while phonoreceptors specifically detect sound.

Ringworm is the odd one out because it is a fungal infection (dermatophytosis), not a worm. Guineaworm, Hookworm, and Tapeworm are all actual parasitic worms (helminths) that infect humans. The name 'ringworm' is misleading - it's caused by fungi, not parasitic worms.

Capacitation is the final maturation step sperm undergo in the female reproductive tract, which includes the acrosome reaction. The acrosome releases enzymes to penetrate the egg's zona pellucida. It does not involve sperm size change, nuclear chromatin alteration, or mitochondrial alignment.

Marfan syndrome is an autosomal dominant connective tissue disorder affecting multiple systems including eyes (lens dislocation), cardiovascular system (aortic aneurysm, valve problems), and skeletal system (tall stature, scoliosis, hyperflexible joints). Since it affects all these systems, 'All of the above' is the correct answer.

Influenza has caused several pandemics throughout history, including the 1918 Spanish flu pandemic, 1957 Asian flu, 1968 Hong Kong flu, and 2009 H1N1 pandemic. Amoebic dysentery, Hepatitis, and Filariasis are important diseases but are classified as endemic or epidemic, not pandemic.

Sarcoplasm is the cytoplasm of striated muscle fibers, containing organelles, glycogen granules, and myoglobin. Sarcomere is the functional unit of muscle contraction, not the cytoplasmic segment. Metamere refers to a body segment, and neuromere is a segment of the nervous system.

Poliovirus is transmitted through the fecal-oral route, primarily via contaminated food and water. It is not transmitted through mosquito or tick bites (those are vectors for other diseases), nor through saliva and nasal secretions. Proper sanitation and vaccination have been crucial in polio eradication efforts.

The corpus striatum (basal ganglia) is located deep within the cerebral hemispheres of the forebrain. Paracoel (lateral ventricle), diocoel (third ventricle), and metacoel (fourth ventricle) are all ventricles (fluid-filled cavities), not locations where the corpus striatum is found.

Adenine and guanine are purines. In humans, purine metabolism end products are excreted as uric acid. Ammonia is excreted by aquatic animals. Urea is the excretory product of amino acid metabolism (urea cycle). Allantoin is further breakdown of uric acid in some mammals but not in humans.

The autonomic nervous system (ANS) controls involuntary functions including heart rate and force (cardiac regulation) and digestive gland secretions (gastrointestinal regulation). The CNS processes information but the ANS executes these specific involuntary controls. Spinal and cranial nerves are pathways but don't regulate these functions autonomously.

Cuttlefish belongs to phylum Mollusca (class Cephalopoda). Globe fish belongs to phylum Chordata (class Actinopterygii - bony fish). Starfish belongs to phylum Echinodermata. Silverfish belongs to phylum Arthropoda (class Insecta). Only cuttlefish is a mollusk.

The trophoblast layer of the blastocyst gives rise to extra-embryonic membranes including the chorion, while the inner cell mass forms the embryo proper. The inner cell mass is restricted to embryonic structures, formative cells is not standard terminology, and follicle cells are ovarian structures unrelated to embryonic membranes.

At high altitudes, lower oxygen pressure stimulates increased erythropoietin production, causing polycythemia - elevated RBC and hemoglobin concentration. This gives skin a rosy appearance. Option A is incorrect because hemoglobin affinity actually decreases (right shift of oxygen dissociation curve) to facilitate oxygen release to tissues. Option C is not the primary physiological adaptation.