Comprehensive Biology Test 4
201. Vector of Malaria:
Ans: Female Anopheles Mosquito
Explanation:
Female Anopheles mosquitoes transmit malaria by injecting Plasmodium parasites during blood meals. Only females feed on blood.
202. Nitrogen-Rich Food:
Ans: Protein
Explanation:
Proteins are rich in nitrogen, essential for growth, tissue repair, enzymes, and hormones in humans and animals.
203. Gases Contributing to Greenhouse Effect:
Ans: Carbon Dioxide and Methane
Explanation:
CO₂ and CH₄ trap heat in the atmosphere, leading to global warming and climate change, impacting ecosystems and human life.
204. Disease Caused by Vitamin C Deficiency:
Ans: Scurvy
Explanation:
Scurvy results from vitamin C deficiency, causing gum bleeding, weakness, and poor wound healing, as vitamin C is essential for collagen synthesis.
205. To Prevent Tooth Decay, Toothpaste Contains:
Ans: Fluoride
Explanation:
Fluoride strengthens enamel, reduces acid production by bacteria, and prevents dental cavities. It is commonly added to toothpaste and drinking water.
206. Silk Produced in Which Stage of Silkworm Life Cycle:
Ans: Pupa
Explanation:
Silkworms spin cocoons during the pupal stage, producing silk threads used commercially for textile manufacturing.
207. Conversion of Starch to Sugar Occurs Where:
Ans: Small Intestine
Explanation:
Starch digestion into glucose occurs primarily in the small intestine by amylase enzymes for absorption into the bloodstream.
208. BT Seed Associated With:
Ans: Cotton
Explanation:
BT cotton contains Bacillus thuringiensis gene, producing toxins against bollworm pests, reducing pesticide use and improving yield.
209. Protein Factory Called:
Ans: Ribosome
Explanation:
Ribosomes are cellular organelles where mRNA is translated into proteins. They exist freely or attached to rough ER in eukaryotes.
210. Blood Cancer Called:
Ans: Leukemia
Explanation:
Leukemia is a cancer of white blood cells, leading to uncontrolled proliferation and impaired immunity.
211. Nocturnal Animal:
Ans: Bat
Explanation:
Bats are nocturnal mammals, active at night, using echolocation for navigation and hunting insects in darkness.
212. 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 dietary fiber.
213. Nitrogen in Urea Fertilizer Exists As:
Answer: Amide
Explanation:
Urea (CO(NH₂)₂) contains nitrogen in amide form, which plants absorb for amino acid and protein synthesis.
214. Special Feature of Fish Heart:
Ans: Two-Chambered Heart
Explanation:
Fish have a single circulation system with a two-chambered heart (one atrium, one ventricle), circulating blood once per cycle.
215. Male Mosquito Feeds On:
Ans: Plant Sap
Explanation:
Male mosquitoes feed on nectar or plant juices for energy; only females feed on blood for egg development.
216. Blood Group Lacking Antibodies:
Ans: AB
Explanation:
AB blood group has both A and B antigens and no antibodies, making them universal recipients in transfusions.
217. Eustachian Tube Located In:
Ans: Ear
Explanation:
The eustachian tube connects the middle ear to the throat, equalizing pressure across the eardrum for hearing.
218. Prothallus Found In:
Answ: Pteridophyta
Explanation:
Prothallus is the gametophyte stage in ferns and other pteridophytes, producing gametes for sexual reproduction.
219. Sugarcane Propagated Vegetatively Because:
Ans: Rare Seed Production
Explanation:
Sugarcane is propagated by stem cuttings since seeds are rarely produced, ensuring faster and uniform cultivation.
220. Beekeeping Called:
Ans: Apiculture
Explanation:
Apiculture is the practice of maintaining bee colonies for honey, wax, and pollination benefits.
221. Acid-Secreting Cell Produces:
Ans: Hydrochloric Acid
Explanation:
Stomach acid-secreting cells release HCl for protein digestion and killing microbes in food.
222. Vector of Malaria:
Ans: Female Anopheles Mosquito
Explanation:
Only female Anopheles mosquitoes transmit malaria by injecting Plasmodium parasites during blood meals.
223. Nitrogen-Rich Food:
Ans: Protein
Explanation:
Proteins are rich in nitrogen, crucial for growth, tissue repair, enzymes, and hormones.
224. Gases Contributing to Greenhouse Effect:
Ans: Carbon Dioxide and Methane
Explanation:
CO₂ and CH₄ trap heat in the atmosphere, causing global warming and affecting climate patterns.
225. Disease Caused by Vitamin C Deficiency:
Ans: Scurvy
Explanation:
Vitamin C deficiency leads to scurvy, causing gum bleeding, weakness, and poor wound healing.
226. To Prevent Tooth Decay, Toothpaste Contains:
Ans: Fluoride
Explanation:
Fluoride strengthens enamel, reduces acid formation by bacteria, and prevents dental cavities.
227. Silk Produced in Which Silkworm Stage:
Ans: Pupa
Explanation:
Silkworm pupae spin cocoons, producing silk threads for commercial use.
228. Starch Converted to Sugar In:
Ans: Small Intestine
Explanation:
Starch is broken down into glucose in the small intestine by amylase for absorption.
229. BT Seed Related To:
Ans: Cotton
Explanation:
BT cotton contains a gene from Bacillus thuringiensis, producing toxin to protect against bollworm pests.
230. Protein Factory Called:
Ans: Ribosome
Explanation:
Ribosomes are the site of protein synthesis, translating mRNA into functional proteins.
231. Blood Cancer Called:
Ans: Leukemia
Explanation:
Leukemia is cancer of white blood cells, leading to abnormal proliferation and impaired immunity.
232. Nocturnal Animal:
Ans: Bat
Explanation:
Bats are nocturnal mammals, active at night, using echolocation for navigation and hunting insects.
233. Death of Cells or Tissue in a Living Body Called:
Ans: Neutrophilia (Note: Cell/tissue death is usually Necrosis, Neutrophilia is high neutrophil count)
Explanation:
Necrosis is the uncontrolled death of cells or tissue due to injury, infection, or toxins, leading to loss of function in that area.
234. Blood Pressure Exists On:
Ans: Walls of Arteries
Explanation:
Blood pressure is the force exerted by circulating blood on the arterial walls, measured to assess heart and vessel health.
235. Food That Can Feed More People:
Ans: Plant Products
Explanation:
Plant-based foods are more efficient in calorie production per hectare compared to animal products, helping support larger populations.
236. Heart Murmur Indicates:
Ans: Defective Valve
Explanation:
A heart murmur is an abnormal sound due to turbulent blood flow, often caused by faulty heart valves (stenosis or regurgitation).
237. One Gene Controlling Multiple Traits Is:
Ans: Pleiotropic
Explanation:
Pleiotropy occurs when a single gene affects multiple phenotypic traits, such as sickle cell gene affecting blood and other tissues.
238. Heavy Alcohol Consumption Leads To:
Ans: Cirrhosis
Explanation:
Excessive alcohol damages liver cells, causing cirrhosis, where healthy tissue is replaced by fibrous tissue, impairing liver function.
239. Organ Where Urine Is Formed:
Ans: Kidney
Explanation:
Kidneys filter blood, removing waste and excess water to form urine, maintaining body fluid and electrolyte balance.
240. Source of Oxygen Released in Photosynthesis:
Ans: Water
Explanation:
During photosynthesis, water molecules split in light reactions, releasing oxygen as a by-product.
241. One Gene One Enzyme Hypothesis Proposed By:
Ans: Beadle & Tatum
Explanation:
Beadle and Tatum demonstrated that each gene encodes a specific enzyme responsible for a single biochemical reaction.
242. Chemical Name of Vitamin A:
Ans: Retinol
Explanation:
Vitamin A (Retinol) is essential for vision, growth, reproduction, and maintaining epithelial tissues.
243. Primary Product of Photosynthesis:
Ans: Glucose
Explanation:
Photosynthesis converts light energy, CO₂, and water into glucose (energy-rich sugar) and oxygen.
245. Normal Human Body Temperature:
Ans: 98.6°F / 37°C / 310K
Explanation:
The normal body temperature maintains metabolic homeostasis and enzymatic activity in humans.
246. Yellow Color of Urine Due To:
Ans: Urochrome
Explanation:
Urochrome, a pigment resulting from hemoglobin breakdown, gives urine its characteristic yellow color.
247. Where Immunity Against Pathogens Is Developed:
Ans: Lymph Nodes & Thymus
Explanation:
Lymph nodes and thymus produce lymphocytes and antibodies for adaptive immunity against infections.
248. Number of Permanent Teeth in Humans:
Ans: 32
Explanation:
Humans develop 32 permanent teeth after replacing the 20 primary teeth.
249. Kyoto Protocol Related To:
Ans: Clean Environment & Climate Change
Explanation:
Kyoto Protocol is an international treaty committing countries to reduce greenhouse gas emissions to combat climate change.
250. Best Dairy Breed:
Answer: Holstein-Friesian
Explanation:
Holstein-Friesians are known for high milk yield, making them the most productive dairy breed worldwide.