Comprehensive Biology Test 11
501. Cholesterol is absent in - Groundnut oil.
Explanation: Cholesterol is found only in animal fats, not in plant-based oils like groundnut oil.
502. Insufficient blood supply to body tissues - Ischemia.
Explanation: Ischemia reduces oxygen delivery, leading to tissue damage or heart attack.
503. International Commission on Zoological Nomenclature established - 1895.
Explanation: It standardizes rules for naming animal species globally to avoid confusion.
504. Basic characteristic of living organisms - Respiration.
Explanation: Respiration allows living beings to release energy from food for cellular activities.
505. Father of Medicine - Hippocrates.
Explanation: Hippocrates, a Greek physician, introduced scientific methods in medicine and ethical medical practice.
506. Cells with shortest life span - Intestinal cells.
Explanation: Intestinal epithelial cells renew every few days due to constant wear and digestion.
507. Bees are used for - Apiculture.
Explanation: Apiculture (beekeeping) produces honey, wax, and aids in pollination.
508. Protein digestion occurs in - Small intestine.
Explanation: Enzymes like trypsin and peptidase break proteins into amino acids for absorption
509. Pathogenic bacteria secrete - Antigens.
Explanation: Antigens trigger immune response; body forms antibodies to neutralize them.
510. Insulin is secreted by - Pancreas.
Explanation: Pancreatic β-cells produce insulin, maintaining blood glucose balance.
511. Language used for scientific naming of organisms - Latin.
Explanation: Latin ensures universal recognition and consistency in biological classification.
512. Master gland of human body - Pituitary gland.
Explanation: The pituitary controls other endocrine glands by secreting hormones like GH, TSH, and FSH.
513. Air pollution particles damaging vital organs are - PM 2.5.
Explanation: PM2.5 are fine particles that penetrate lungs and bloodstream, causing respiratory and heart diseases.
514. Dialysis works on - Diffusion principle.
Explanation: Dialysis removes waste from blood by allowing small molecules to pass through a semi-permeable membrane.
515. Anaemia is caused by deficiency of - Iron.
Explanation: Lack of iron reduces hemoglobin, leading to fatigue and pale skin.
516. Reflex actions are controlled by - Spinal cord.
Explanation: The spinal cord quickly processes reflexes without involving the brain.
517. Vitamin B6 deficiency in men causes - Anaemia.
Explanation: Vitamin B6 is vital for hemoglobin synthesis; its deficiency reduces red blood cell production.
518. Instrument used to measure stem growth rate - Auxanometer
Explanation: It measures the growth of plant stems by recording changes in length over time due to cell elongation and turgor pressure.
519. Harmful substance in tobacco smoke - Nicotine
Explanation: Nicotine is an addictive alkaloid that affects the nervous system, increasing heart rate and blood pressure, and leading to dependency.
520. Pancreas secretes which hormone? - Insulin
Explanation: Insulin regulates blood sugar by converting excess glucose into glycogen for storage in the liver and muscles, maintaining normal glucose levels.
521. Yellowish color of cow’s milk is due to - Carotene
Explanation: Carotene is a natural yellow pigment and a precursor of Vitamin A that gives cow’s milk its characteristic light-yellow color.
522. Transplant between genetically identical individuals - Isograft
Explanation: Isograft occurs between identical twins or clones; since genetic makeup is identical, there is no immune rejection.
523. Lactose is found in - Milk
Explanation: Lactose is a natural sugar (disaccharide) in milk; it provides energy and helps in calcium absorption during digestion.
524. Meiosis occurs in - Reproductive cells
Explanation: Meiosis occurs in gamete-producing cells, reducing chromosome number by half and ensuring genetic variation in offspring.
525. Study of cells is called - Cytology
Explanation: Cytology deals with the structure, function, and composition of cells — the smallest and most basic unit of life.
526. Proteins are digested by - Protease
Explanation: Protease enzymes break down complex protein molecules into simpler amino acids, aiding in nutrient absorption in the small intestine.
527. Xerophthalmia is caused by deficiency of -Vitamin A
Explanation: Vitamin A deficiency leads to dryness of the eyes, damage to the cornea, and can cause night blindness.
528. Stomatal opening is based on - Endosmosis
Explanation: Endosmosis causes water to enter guard cells, making them turgid and opening stomata for gas exchange and transpiration.
529. Emulsification means - Breaking fats into small globules
Explanation: Bile salts from the liver break large fat molecules into tiny droplets, increasing enzyme action for efficient fat digestion.
530. Double helix model of DNA was proposed by - Watson and Crick
Explanation: They described DNA as two intertwined helical strands with complementary base pairing, carrying genetic instructions for life.
531. Mendel is famous for - Genetic laws
Explanation: Gregor Mendel discovered fundamental laws of inheritance using pea plants, forming the basis of modern genetics.
532. Exhaled air contains about - 4% Carbon dioxide
Explanation: During respiration, cells release CO₂ as a waste product, which is exhaled while oxygen is inhaled for metabolism.
533. Percentage of fat in ghee - 99%
Explanation: Ghee is nearly pure fat, providing high energy but lacking proteins and carbohydrates; overconsumption may cause obesity.
534. Sex chromosomes are called - Allosomes
Explanation: Allosomes determine sex: XX for females and XY for males; they carry genes for sexual traits.
535. Digestive bag of the cell is - Lysosome
Explanation: Lysosomes contain digestive enzymes that break down cell debris, bacteria, and worn-out organelles — acting as the cell’s waste disposal unit.
536. Master copy of genetic information - DNA
Explanation: DNA stores hereditary information, controls protein synthesis, and ensures genetic continuity between generations.
537. Term "Rhizosphere" was given by - Hiltner
Explanation: Rhizosphere is the soil zone around roots influenced by root secretions and microbial activity, promoting plant growth.
538. Another name for kneecap - Patella
Explanation: The patella is a small bone in front of the knee joint that protects it and aids leg movement.
539. Main components of food - Fats, Proteins, Carbohydrates
Explanation: These macronutrients provide energy, build body tissues, and maintain essential body functions.
540. Green pigment responsible for photosynthesis - Chlorophyll
Explanation: Chlorophyll absorbs sunlight (mainly red and blue wavelengths) and converts it into chemical energy during photosynthesis.
541. Which is the most sensitive indicator of the health of a community ?
Ans: Infant Mortality Rate
Explanation: Infant mortality rate shows how many infants die before one year. It reflects health care, nutrition, and hygiene standards of a community - hence the best indicator.
542. Which part of the elephant turns into tusks ?
Ans: Second incisor teeth
Explanation: The elephant’s tusks are elongated second incisors made of ivory, used for digging, defense, and lifting objects.
543. Which source is especially productive in nature ?
Ans: Marine source
Explanation: Oceans and seas are rich in minerals, planktons, and aquatic organisms, making marine sources highly productive biologically and economically.
544. Lichen is a symbiotic association between ?
Ans: Algae and Fungi
Explanation: Algae prepare food through photosynthesis, while fungi provide shelter and absorb moisture. Both live together mutually benefiting each other.
545. Many grass leaves can roll and unroll due to ?
Ans: Presence of special motor cells
Explanation: Grasses have bulliform (motor) cells that help roll leaves during water stress to reduce transpiration and unroll when hydrated.
546. What is used in the treatment of cancer ?
Ans: Chemotherapy
Explanation: Chemotherapy uses powerful chemicals to kill fast-growing cancer cells, slowing or stopping the spread of tumors in the body.
547. What is meant by the greenhouse effect ?
Ans: Trapping of solar energy by carbon dioxide and other gases
Explanation: Greenhouse gases like CO₂ trap heat in the atmosphere, increasing Earth's temperature and causing global warming.
548. Waste from toilets and urinals is called ?
Ans: Sanitary waste
Explanation: Human excreta and urine collected from toilets are termed sanitary waste, needing safe disposal to prevent pollution and diseases.
549. Red color of tomato is due to ?
Ans: Lycopene
Explanation: Lycopene is a red pigment and antioxidant in tomatoes that gives color and helps protect cells from damage.
550. Which organelle differentiates plant and animal cells ?
Ans: Chloroplast
Explanation: Chloroplasts are found only in plant cells for photosynthesis; animal cells lack them, making this a key difference.