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