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