Comprehensive Biology Test 14

651. Saliva Digest Which Substance:


Ans: Starch
Explanation:
Saliva contains amylase, which breaks down starch into maltose in the oral cavity.


652. Optimal Dissolved Oxygen for Aquatic Life:


Ans: 4–6 mg/L
Explanation:
Aquatic organisms require 4–6 mg/L dissolved oxygen for respiration and survival; lower levels stress or kill aquatic life.


653. Thickest Skin in Human Body:


Ans: Soles of Feet
Explanation:
The skin on the soles is thickest to withstand pressure, friction, and protect underlying tissues.


654. 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.


655. 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.


656. 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.


657. 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).


658. 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.


659. 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.


560. 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.


561. Source of Oxygen Released in Photosynthesis:


Ans: Water
Explanation:
During photosynthesis, water molecules split in light reactions, releasing oxygen as a by-product.


562. 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.


563. Chemical Name of Vitamin A:


Ans: Retinol
Explanation:
Vitamin A (Retinol) is essential for vision, growth, reproduction, and maintaining epithelial tissues.


564. Primary Product of Photosynthesis:


Ans: Glucose
Explanation:
Photosynthesis converts light energy, CO₂, and water into glucose (energy-rich sugar) and oxygen.


565. Normal Human Body Temperature:


Ans: 98.6°F / 37°C / 310K
Explanation:
The normal body temperature maintains metabolic homeostasis and enzymatic activity in humans.


565. Yellow Color of Urine Due To:


Ans: Urochrome
Explanation:
Urochrome, a pigment resulting from hemoglobin breakdown, gives urine its characteristic yellow color.


566. Where Immunity Against Pathogens Is Developed:


Ans: Lymph Nodes & Thymus
Explanation:
Lymph nodes and thymus produce lymphocytes and antibodies for adaptive immunity against infections.


567. Number of Permanent Teeth in Humans:


Ans: 32
Explanation:
Humans develop 32 permanent teeth after replacing the 20 primary teeth.


568. 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.


569. Best Dairy Breed:


Ans: Holstein-Friesian
Explanation:
Holstein-Friesians are known for high milk yield, making them the most productive dairy breed worldwide.


570. Cause of Jaundice:


Ans: Liver Infection
Explanation:
Jaundice occurs due to excess bilirubin from liver dysfunction, often caused by hepatitis or bile duct blockage.


571. Protein That Prevents Blood Clotting:


Ans: Heparin
Explanation:
Heparin inhibits clotting factors, preventing coagulation and maintaining smooth blood flow in the circulatory system.


572. Quinine Obtained From Which Part of Plant:


Ans: Bark
Explanation:
Quinine, used to treat malaria, is extracted from the bark of the Cinchona tree.


573. Incubation Done By:


Ans: Birds
Explanation:
Birds incubate eggs using body warmth, allowing embryo development until hatching.


574. Immediate Energy Supplied to Athletes Comes From:


Ans: Carbohydrates
Explanation:
Carbohydrates are rapidly metabolized to glucose, providing instant energy for high-intensity activities.