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