Restriction enzymes /Endonucleases or Exonucleases) SECTION-B 9. 1+1=2 (I) Only one pollen tube enters an ovule so 10 pollen tubes will be required for 10 ovules. (ii) Out of two male gametes per pollen tube, one is used 10. in syngamy and other gamete in triple fusion. 1+1=2 (a) Rr (b) None of the parental allele for colour is dominant or recessive showing incomplete dominance. 11. Single Polynucleotide chain a- transmitted through house flies from faeces of infected persons to water,food and food products and thereby by contaminating them b- Ringworm c- Rhinovirus 1+1 d- Internal bleeding/anaemia/muscular pain (any one) (a) Intestine of mosquito 12. (b) RBCs of human (c) Salivary gland of mosquito (d)Liver cell/ RBCs of human ½x4 (a) Inject antitoxin/tetanus injection 13. (b) Passive immunity (a) Bees are pollinators of crop plant (b) Provide better yield of honey for bees. ½x4 14. (a) More tolerant to abiotic stress (b) Provide better yields of crop 1+1 (c) Reduced post harvest losses 15. (d) Increased nutritional value of food. 1+1 (a)kills fish (b) disappearance of clean 16. water(c)reappearance of clean water (d) reappearance of clean water ½x4 (i) (a) N2O (b) CFCs 17. (ii) Green house gases cause global warming which in turn causes melting of ice caps. 1+1
9. 10. 11. 12. 13. 14. 15. 16. 17. Restriction enzymes /Endonucleases or Exonucleases) SECTION-B (I) Only one pollen tube enters an ovule so 10 pollen tubes will be required for 10 ovules. (ii) Out of two male gametes per pollen tube, one is used in syngamy and other gamete in triple fusion. (a) Rr (b) None of the parental allele for colour is dominant or recessive showing incomplete dominance. Single Polynucleotide chain a- transmitted through house flies from faeces of infected persons to water,food and food products and thereby by contaminating them b- Ringworm c- Rhinovirus d- Internal bleeding/anaemia/muscular pain (any one) (a) Intestine of mosquito (b) RBCs of human (c) Salivary gland of mosquito (d)Liver cell/ RBCs of human (a) Inject antitoxin/tetanus injection (b) Passive immunity (a) Bees are pollinators of crop plant (b) Provide better yield of honey for bees. (a) More tolerant to abiotic stress (b) Provide better yields of crop (c) Reduced post harvest losses (d) Increased nutritional value of food. (a)kills fish (b) disappearance of clean water(c)reappearance of clean water (d) reappearance of clean water (i) (a) N2O (b) CFCs (ii) Green house gases cause global warming which in turn causes melting of ice caps. 1+1=2 1+1=2 1+1 ½x4 ½x4 1+1 1+1 ½x4 1+1
1250565124study_material_of_class_xii_-biology,.docx