Comprehensive Biology Test 3
151. Tallest and Thickest Grass:
Ans: Bamboo
Explanation:
Bamboo is the tallest and thickest grass. It grows rapidly, is woody, and is used for construction, paper, and various industrial and cultural purposes.
152. Where Wild Asses Are Found in India:
Ans: Rann of Kutch
Explanation:
The Indian wild ass (Equus hemionus khur) is found in the saline desert of the Rann of Kutch, Gujarat, and is adapted to arid environments.
153. Tissue Forming Camel’s Hump:
Ans: Adipose Tissue
Explanation:
Camel humps store fat (adipose tissue) that provides energy and water during scarcity. It helps camels survive harsh desert conditions.
154. Rich Source of Vitamin A:
Ans: Carrot
Explanation:
Carrots are rich in beta-carotene, a precursor of vitamin A, essential for vision, skin health, and immunity.
155. Diseases Transmitted by Blood:
Ans: Hepatitis, HIV, Malaria
Explanation:
Blood-borne diseases like hepatitis, HIV, and malaria spread through contaminated blood, transfusion, or vectors, affecting the liver, immune system, and red blood cells.
156. Disease Caused by Insufficient Iodine Intake:
Ans: Goiter
Explanation:
Iodine deficiency leads to thyroid enlargement (goiter), affecting metabolism and growth, commonly observed in areas with iodine-poor soil.
157. Hormone Secreted in Response to Stimuli:
Ans: Adrenaline
Explanation:
Adrenaline is released during stress or excitement, increasing heart rate, blood pressure, and energy availability for “fight-or-flight” response.
158. Largest Organ in Human Body:
Ans: Liver
Explanation:
The liver is the largest internal organ, performing detoxification, metabolism, bile production, storage of nutrients, and synthesis of plasma proteins.
159. Typhoid Measured By:
Ans: Widal Test
Explanation:
Typhoid fever, caused by Salmonella typhi, is diagnosed using the Widal test, which detects specific antibodies in blood against the pathogen.
160. Hemophilia Is:
Ans: Genetic Disorder
Explanation:
Hemophilia is an inherited blood-clotting disorder caused by deficiency of clotting factors, leading to prolonged bleeding after injuries.
161. Use of Potato Eyes:
Ans: Vegetative Propagation
Explanation:
Potato eyes are buds that sprout into new plants. They are used for asexual reproduction, producing genetically identical offspring.
162. Pollutant Concentration Expressed in Environment:
Ans: PPM (Parts Per Million)
Explanation:
Pollutant concentration in air, water, or soil is commonly expressed in PPM to indicate the number of pollutant units per million units of environment.
163. Disease Rabies Caused By:
Ans: Dog Bite
Explanation:
Rabies is a viral disease transmitted through the saliva of infected animals, primarily dogs, causing neurological symptoms and often death if untreated.
164. Old and Damaged Red Blood Cells Destroyed In:
Ans: Spleen
Explanation:
The spleen filters and removes aged or defective red blood cells from circulation, recycling iron and maintaining healthy blood composition.
165. First Description of Color Blindness in Humans:
Ans: By Herner (1876)
Explanation:
Herner first documented color blindness in humans, describing the inability to distinguish certain colors due to defective photoreceptors in the retina.
166. Cause of Blood Clotting:
Ans: Fibrinogen/Fibrin Formation
Explanation:
Blood clots form when fibrinogen converts to fibrin during injury, preventing excessive blood loss and facilitating wound healing.
167. Sea Sickness (Motion Sickness) Due to:
Ans: Movement Absorption in Inner Ear
Explanation:
Motion sickness occurs due to mismatch between sensory signals from inner ear, eyes, and muscles, causing nausea and dizziness during boat or vehicle movement.
168. Element in Chlorophyll:
Ans: Magnesium
Explanation:
Magnesium forms the central atom in chlorophyll molecules, essential for capturing light energy in photosynthesis.
169. Average Lifespan of Red Blood Cells:
Ans: 100–120 Days
Explanation:
Human red blood cells live approximately 100–120 days, after which they are removed by spleen or liver and replaced by newly produced cells.
170. Flat Bones Found In:
Ans: Skull
Explanation:
Flat bones like the cranial bones protect the brain, provide broad surfaces for muscle attachment, and contribute to structural support in the body.
171. Metal Present in Hemoglobin:
Ans: Iron
Explanation:
Hemoglobin contains iron, which binds oxygen in red blood cells and facilitates transport from lungs to tissues, giving blood its red color.
171. Biological Death Means:
Ans: Brain Tissue Death
Explanation:
Biological death occurs when brain cells die, leading to irreversible loss of vital functions like breathing and heartbeat, even if other organs temporarily function.
172. Most Important Stimulant in Tea Leaves:
Ans: Caffeine
Explanation:
Caffeine in tea leaves acts as a central nervous system stimulant, increasing alertness and reducing fatigue when consumed in moderate amounts.
173. Tachycardia:
Ans: Increased Heart Rate
Explanation:
Tachycardia is a condition where heart beats faster than normal (>100 beats per minute at rest), which can result from stress, fever, or heart disorders.
174. Site of Hematopoiesis:
Ans: Bone Marrow
Explanation:
Blood formation (hematopoiesis) occurs in red bone marrow, producing RBCs, WBCs, and platelets throughout life.
175. Freshwater Fish in Saltwater:
Ans: Will Die from Dehydration
Explanation:
Freshwater fish placed in saltwater lose water through osmosis, leading to dehydration, osmotic imbalance, and eventual death.
176. Natural Colloid:
Ans: Blood
Explanation:
Blood is a natural colloid containing cells (dispersed phase) in plasma (dispersion medium), maintaining flow and transport of nutrients and wastes.
177. Increased RBC Leads To:
Ans: Polycythemia
Explanation:
Polycythemia is a condition with elevated red blood cell count, increasing blood viscosity, which may strain the heart and circulation.
178. Discovery of Vitamins:
Ans: Funk
Explanation:
Casimir Funk discovered vitamins and proposed that deficiencies of essential organic compounds in the diet cause specific diseases.
179. Organ Affected by Diphtheria:
Ans: Throat
Explanation:
Diphtheria infects the throat, causing membrane formation, difficulty in breathing and swallowing, and potential systemic complications if untreated.
180. Requirements for Photosynthesis:
Ans: Sunlight, Water, Green Chlorophyll
Explanation:
Photosynthesis requires sunlight for energy, water as a hydrogen source, and chlorophyll to capture light, producing glucose and oxygen in plants.
181. Universal Blood Group:
Ans: AB
Explanation:
AB blood group individuals have both A and B antigens and no antibodies, making them universal recipients in transfusions.
182. Smallest Gland in the Body:
Ans: Pituitary
Explanation:
The pituitary gland is a small endocrine gland controlling hormones for growth, reproduction, and metabolism.
183. Wisdom Tooth:
Ans: Third Molar
Explanation:
The third molars, also called wisdom teeth, usually appear in late teens or early twenties and often require removal if misaligned.
184. Type of Kidneys in Frog:
Ans: Mesonephros
Explanation:
Frogs have mesonephric kidneys functioning in excretion and osmoregulation, typical of amphibians.
185. Blood Vessel Carrying Oxygenated Blood to Liver:
Ans: Hepatic Artery
Explanation:
The hepatic artery supplies oxygen-rich blood to the liver for metabolic activity, supporting detoxification and nutrient processing.
186. Human Eye Functions Like:
Ans: Convex Lens
Explanation:
The human eye lens is convex, focusing light on the retina to form clear images, adjustable for near and far vision.
187. Danger of Air Bubbles in Blood Flow:
Ans: Can Block Circulation
Explanation:
Air bubbles in blood (embolism) can obstruct vessels, preventing oxygen supply to organs, potentially causing organ failure or death.
188. Main Metal in Chlorophyll (Non-Vascular Plants):
Ans: Magnesium
Explanation:
Magnesium is the central atom in chlorophyll molecules, essential for photosynthesis, capturing light energy in green algae and other chlorophyll-containing organisms.
189. Platelets Help In:
Ans: Blood Clotting
Explanation:
Platelets (thrombocytes) are cell fragments that help form clots, preventing excessive blood loss after injuries. They release clotting factors and aggregate at wound sites.
190. Most Abundant Organic Compound in Nature:
Ans: Cellulose
Explanation:
Cellulose is the most abundant organic polymer, forming plant cell walls, providing structural support, and serving as a source of dietary fiber in animals.
191. Nitrogen in Urea Fertilizer:
Ans: Present as Amide
Explanation:
Urea (CO(NH₂)₂) is a nitrogen-rich fertilizer. Nitrogen exists in amide form, which plants absorb for amino acid and protein synthesis.
192. Special Feature of Fish Heart:
Ans: Two-Chambered Heart
Explanation:
Fish have a two-chambered heart (one atrium, one ventricle), allowing single circulation where blood passes through heart once per cycle.
193. Male Mosquito Feeds On:
Ans: Plant Sap
Explanation:
Male mosquitoes do not suck blood; they feed on nectar or plant juices for energy, while females require blood for egg development.
195. Absence of Antibodies in Blood Group:
Ans: AB
Explanation:
AB blood group has both A and B antigens and lacks anti-A and anti-B antibodies, making it a universal recipient.
196. Eustachian Tube Located In:
Ans: Ear
Explanation:
The eustachian tube connects middle ear to throat, equalizing air pressure across the eardrum for proper hearing and preventing fluid buildup.
197. Prothallus Called In:
Ans: Pteridophyta
Explanation:
The prothallus is the gametophyte stage in ferns and other pteridophytes, producing gametes for sexual reproduction.
198. Sugarcane Propagated By Vegetative Means Because:
Ans: Seeds Rarely Produced
Explanation:
Sugarcane is propagated vegetatively via stem cuttings, as it rarely produces viable seeds. Vegetative propagation ensures uniformity and faster cultivation.
199. Beekeeping Called:
Ans: Apiculture
Explanation:
Apiculture is the practice of maintaining bee colonies for honey, wax, and other products, supporting agriculture through pollination.
200. Acid-Secreting Cell Produces:
Ans: Hydrochloric Acid
Explanation:
Gastric acid-secreting cells in the stomach produce hydrochloric acid (HCl), aiding protein digestion and providing acidic environment to kill microbes.