MCQs Biology-20 Posted on November 27, 2025December 3, 2025Author agropublishers 0 MCQs Biology-20 1. Rhizobium is an example of ———–bacteria Chemosynthetic Saprophytic Parasitic Symbiotic nitrogen-fixing 2. Toxicology studies ———– DNA replication Harmful effects of chemicals on organisms Beneficial chemicals Protein synthesis 3. Which example cannot describe a sample? 25 students chosen randomly 12 leaves measured from one tree 105 plants chosen from a field All plants in the field 4. The discovery of mustard gas as a mutagen was significant because it showed that __________. Mutations could not be induced artificially Radiation was the only mutagenic agent Mutations were always lethal Chemicals could also induce heritable genetic changes 5. Microscopic gaps between the endings of one neuron and another cell are called__________ Pores Nodes Synapses Transmitters 6. The number of crossovers per bivalent depends on ——– Centriole number Chromosome size Cytoplasmic volume Cell size 7. Recombinant DNA technology is primarily used in ———– Molecular cloning Anatomy studies Ecosystem monitoring Fossil analysis 8. A protoplast is best defined as _____________ The living part of a cell, including the cytoplasm and nucleus The plasma membrane and all cellular contents it surrounds A plant cell with its cell wall removed A plant cell, after removing its cell wall, containing the plasma membrane and all cellular contents it surrounds Loading … Question 1 of 8
