MCQs Botany-40 Posted on October 27, 2025December 3, 2025Author agropublishers 0 MCQs Botany-40 1. Non-coding RNAs, such as microRNAs (miRNAs), can be considered part of epigenetic regulation because they___________ Directly repair DNA damage Code for histone proteins Are the primary components of chromatin Regulate gene expression at the post-transcriptional level without altering the DNA sequence 2. In plants true roots first evolved among _________ Angiosperms Bryophytes Pteridophytes Gymnosperms 3. The regulation of the Calvin Cycle involves several key mechanisms. The light-activated enzyme Ferredoxin-Thioredoxin System (Fd-Trx system) reduces disulfide bridges on target enzymes. Which of the following enzymes is NOT activated by this reduction? Phosphoribulokinase (PRK) Sedoheptulose-1,7-bisphosphatase (SBPase) Fructose-1,6-bisphosphatase (FBPase) Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) 4. Which of the following nitrogenous bases is NOT found in DNA? Guanine Uracil Thymine Adenine 5. Oxygen generally composed of _______ of biomolecules in living organisms 35% 18% 40% 65% 6. What is the defining characteristic of imprinted genes? They have an exceptionally high rate of spontaneous mutation They are permanently inactivated in all cells of the body They code for the enzymatic machinery involved in epigenetic silencing Their expression is determined by their parental origin, leading to monoallelic expression 7. Roots are absent in _________ Pteridophytes Bryophytes Gymnosperms Angiosperms 8. What term describes a large, naturally occurring community of plants and animals that occupy a specific habitat, such as a forest, desert, or ocean? Niche Ecosystem Habitat Biome 9. The central dogma of molecular biology describes the flow of genetic information as________ RNA → DNA → Protein Protein → DNA → RNA DNA → Protein → RNA DNA → RNA → Protein 10. During photosynthesis, energy is converted from ___ energy into ___ energy, stored in the bonds of glucose Mechanical; Light Chemical; Chemical Kinetic; Chemical Light; Chemical Loading … Question 1 of 10
