Q1. Chromosomes consist of
(a) DNA and lipids
(b) RNA and amino acids
(c) DNA and proteins
(d) RNA and sugar
Ans: (c) A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.
Q2. The yellow colour of urine is due to presence of
Ans: (d) The color of normal urine is usually light yellow to amber. Generally, the greater the solute volume the deeper the color. The yellow color of urine is due to the presence of a yellow pigment, urochrome. Deviations from normal color can be caused by certain drugs and various vegetables such as carrots, beets, and rhubarb.
Q3. Which of the following is known as ‘grave yard’ of RBCs?
(b) Bone marrow
(c) Spleen (d) Appendix
Ans: (c) The old, worn out and dead RBC are destroyed mainly in an organ called spleen. Hence, it is commonly called the ‘graveyard of RBC’.
Q4. The main use of salt in the diet is to
(a) increase the solubility of the food particles in water
(b) produce in small amounts the hydrochloric acid required for the digestion of food
(c) ease the process of cooking
(d) make the taste of the food better
Ans: (b) Salt plays a primary role in the processes of digestion and absorption. Salt activates an enzyme in the mouth called salivary amylase. Salt also creates hydrochloric acid. Hydrochloric acid is a very important digestive secretion, which lines the stomach walls.
Q5. Which of the following is biodegradable?
(a) Paper (b) D. D. T
(c) Aluminium (d) Plastic
Ans: (a) Paper is organic in nature as it is made from wood and pulp. So it is bio-degradable and useful in recycling.
Q6. Which of the following weeds has been found effective in checking water pollution caused by industrial affluents?
(a) Water hyacinth
(b) Elephant Grass
(d) Both (b) and (c)
Ans: (d) Plants that are resistant to crude oil toxicity such as black poplar and willows, as well as miscanthus grass (elephant grass) have been found to be effective in the remediation of oil polluted soil. Bioadsorbents like Moringo oliefera seeds and Parthenium hysterophorus plants. are effective for the removal of industrial pollutants in water.
Q7. Itai-itai disease is due to poisoning caused by
(a) Mercury (b) Arsenic
(c) Cadmium (d) Asbestos
Ans: (c) Itai-itai disease was the documented case of mass cadmium poisoning in Toyama Prefecture, Japan, starting around 1912. The cadmium poisoning caused softening of the bones and kidney failure.
Q8. Blue-green algae are included in the group
(a) Eubacteria (b) Cyanobacteria
(c) Protozoa (d) Fungi
Ans: (b) Cyanobacteria, also known as blue algae, are singlecelled and belong to the family of Prokaryotes. That means, they do not have a cell nucleus. The ability of cyanobacteria to perform oxygenic photosynthesis is thought to have converted the early reducing atmosphere into an oxidizing one, which dramatically changed the composition of life forms on Earth by stimulating biodiversity and leading to the nearextinction of oxygen-intolerant organisms.
Q9. Haemoglobin contains the metal
(a) Copper (b) Molybdenum
(c) Iron (d) Magnesium
Ans: (c) Haemoglobin is an iron-containing protein in red blood cells. It contains a haem prosthetic group that has an iron atom at its centre. When the iron is bound to oxygen, the haem group is red in colour (oxyhameoglobin), and when it lacks oxygen (deoxygenated form) it is blue-red.
Q10. ‘Comose’ seeds are seeds with
(a) Long hairs (b) Wings
(c) Bristles (d) Hooks
Ans: (a) The word ‘comose’ means ‘hairy’ in Latin. It refers to certain seeds (such as cotton) having a tuft or tufts of hair. The seeds of plants like Calotropis, Gossypium, etc, possess a large number of hairs which enable them to float in air. Such seeds are described as comose.
Q11. The sugar present in DNA is
(a) Pentose (b) Xylulose
(c) Hexose (d) Heptulose
Ans: (a) The sugar present in DNA is 2-deoxyribose, which is a pentose.
Q12. A seed can germinate in the absence of
(a) adequate light
(b) supply of oxygen
(c) suitable moisture
(d) suitable temperature
Ans: (a) A seed can germinate in the absence of adequate light.
Q13. Normally animals can change the place, but which one of the following animals cannot change the place ?
(a) Starfish (b) Sponge
(c) Hydra (d) Leech
Ans: (c) Hydras are generally sedentary and sessile.
Q14. Production of alcohol from organic compounds by microorganisms is known as
(c) Anaerobic respiration
(d) Aerobic respiration
Ans: (b) The process of breaking down large molecules into simpler one in the presence of enzyme is called fermentation.
Q15. Odontology is the branch of science which deals with the study of
(a) Teeth (b) Ontogeny
(c) Bone (d) Ageing
Ans: (a) Scientific study of teeth is called Odontology.
Q16. An invertebrate does not have
(a) Notochord (b) Body cavity
(c) Haemocoel (d) Gills
Ans: (a) An invertebrate does not have back bone and cell wall.
Q17. Which of the following agricultural practices have been primarily responsible for pollution of our water resources ?
A. Use of live-stock manure
B. Use of chemical fertilisers
C. Excessive use of chemical pesticides
(a) B and C (b) A, C and D
(c) A and B (d) A, B and D
Ans: (a) Use of chemical fertilisers and excessive use of chemical pesticides are primarly responsible for pollution of our water resources.
Q18. Which of the following weeds has been found useful to check water pollution caused by industrial effluents ?
(b) Elephant grass
(c) Water hyacinth
(d) Both (a) and (b)
Ans: (d) Parthenium and Elephant grass are useful to check water pollution caused by industrial effluents.
Q19. Which of the following does not cause pollution ?
(a) Burning of petrol
(b) Use of solar energy
(c) Burning of rubber
(d) All of the above
Ans: (b) Use of solar energy does not cause pollution.
Q20. Excess amount of absorbed water by plants is liberated out by :
Ans: (d) Water vapour transpires constantly through pores (stomata) in the surface of plant’s leaves.
Q21. What is a sponge ?
(a) a fossil (b) a plant
(c) an animal (d) a fungus
Ans: (c) A sponge is any sessile aquatic animal of the phylum Porifera, with a porous bag-like body structure and a rigid or elastic internal skeleton.
Q22. Types of vertebrate animals which creep and crawl are called :
(c) mollusks (d) reptilians
Ans: (d) The types of vertebrate animals which creep and crawl are called reptilians.
Q23. Which of the following enzymes aids in coagulation of blood?
(a) Tryptase (b) Pepsin
(c) Rennin (d) Amylase
Ans: (c) Amylase converts starch and glycogen into simple sugars. Pepsin is a digestive enzyme. Rennin, the active part of prorennin helps in coagulation of blood.
Q24. Bio – diesel is mostly produced by :
(a) Myrtaceae (b) Malvaceae
Ans: (d) Bio-diesel is mostly produced by Jatropha which is a genus of flowering plants in the spurge family, Euphorbiaceae.
Q25. Flowerless plants are termed as:
Ans: (d) Flowerless plants are termed as Cryptogamous.
Q1. Chromosomes consist of