NCERT Class 12 Biology very short Questions & Answers
31 Transplantation of tissues/organs to save certain patients often fails due to rejection of such tissues/organs by the patient. Which type of immune response is responsible for such rejections?
Answer: cell-mediated immune response
32 Many diseases can be diagnosed by observing the symptoms in the patient. Which group of symptoms are indicative of pneumonia?
Answer: Difficulty in respiration, fever, chills, cough, headache
33 The substance produced by a cell on viral infection that can protect other cells from further infection is
34 Offspring formed by sexual reproduction exhibit more variation than those formed by Asexual reproduction because
Answer: gametes of parents have qualitatively different genetic composition
39 A multicellular, filamentous alga exhibits a type of sexual life cycle in which the meiotic division occurs after the formation of zygote. The adult filament of this alga has
Answer: haploid vegetative cells and haploid gametangia