11. Which among the following option would normally have the highest Biological Oxygen Demand (BOD)?
[A] A running river
[B] A running polluted river
[C] Untreated Municipal waste water
[D] Ocean water
Show Answer
Correct Answer: C [ Untreated Municipal waste water]
Notes:
BOD is amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down organic material present in a given water sample at certain temperature over a specific time period, for running rivers, it would be minimum and for Untreated Municipal waste water it would be maximum.
12. Which of the following is the correct taxonomical arrangement?
[A] Species<Genus<Order<Class
[B] Genus<Species<Order<Class
[C] Species<Genus<Class<Order
[D] Species<Order<Class<Genus
Show Answer
Correct Answer: A [ Species<Genus<Order<Class ]
Notes:
First option is the correct answer.
13. Which organelle is associated with formation of basal granules & flagella?
[A] Centrosome
[B] Golgi apparatus
[C] Mitochondria
[D] Lysosome
Show Answer
Correct Answer: A [ Centrosome]
Notes:
Centrosome is an organelle that serves as the main microtubule organizing centre (MTOC). Basal granules are cellular organelles that are similar to the centriole in structure and are found at the base of a cilium or flagellum.
14. Why does the peepal tree continuously produce oxygen?
[A] C3 Photosynthesis
[B] C4 Photosynthesis
[C] Crassulacean Acid Metabolism
[D] Carbon Cycle Rebalancing
Show Answer
Correct Answer: C [Crassulacean Acid Metabolism]
Notes:
Peepal tree has the capability to absorb CO² at night due to Crassulacean Acid Metabolism (CAM). It’s a photosynthesis pathway primarily found in desert plants and epiphytes (those that live on larger trees). During the day, CAM plants break down the malate created at night and use the released CO² to create sugars, similar to C3 plants. But, CAM, being energy inefficient, is used only under certain conditions. It seems that peepal trees use CAM when they are epiphytic and switch to C3 photosynthesis when they settle in the soil.
15. Root hair in plants are produced from which of the following?
[A] cortex
[B] pericycle
[C] epidermis
[D] endodermis
Show Answer
Correct Answer: C [epidermis]
Notes:
Cells of the epidermis produce root hairs near the root apex. These cells are generally thin-walled, in contrast to the cells of the cortex, lying below the surface, which ultimately may become very thick-walled. The root hairs have fundamental importance in absorption of water and nutrients.
16. In the names Mangifera indica (mango), Solanum tuberosum(potato) and Panthera leo(lion), what does the three names, indica, tuberosum and leo represent?
[A] Taxonomic Hierarchy
[B] Specific Epithet
[C] Binomial Nomenclature
[D] Identification
Show Answer
Correct Answer: B [Specific Epithet]
Notes:
A specific epithet is the second part of a species name in binomial nomenclature in any branch of biology. In botany, the second part of a botanical name. Specific epithet (zoology), also called the specific name, meaning the second part of the species name or binomen.
17. Bile is secreted by which of the following organs? (UPSC Prelims 1985)
[A] Liver
[B] Gall bladder
[C] Kidney
[D] Pancreas
Show Answer
Correct Answer: A [Liver]
Notes:
Bile or gall is a dark green to yellowish brown fluid, produced by the liver of most vertebrates that aids the digestion of lipids in the small intestine. In humans, bile is produced continuously by the liver and stored and concentrated in the gallbladder.
18. For developing in bred lines in farm animals, following factors are taken into consideration:
- The crossbreds should be of outstanding type.
- They should not carry any detrimental genes.
- Progeney tested animals.
- Herd size should be large.
Of the statements given above, which one of the following combinations of factors is most essential?
[A] 1 and 3
[B] 2 and 3
[C] 1 and 4
[D] 2 and 4
Show Answer
Correct Answer: D [2 and 4]
Notes:
Inbreeding results in homozygosity, which can increase the chances of offspring being affected by deleterious or recessive traits. This usually leads to at least temporarily decreased biological fitness of a population which is its ability to survive and reproduce. So for inbreeding they should not carry any detrimental genes and it is effective only if the herd is large.
19. Which one of the following diseases is least infectious?
[A] Leprosy
[B] Tuberculosis
[C] Conjunctivitis
[D] Hepatitis
Show Answer
Correct Answer: D [Hepatitis]
Notes:
Most noninfectious causes of hepatitis are not contagious. Hepatitis caused by alcohol poisoning, medications, or toxins or poisons are not transmitted from person to person.
20. Which of the following groups consists entirely of essential trace mineral nutrients for humans? (UPSC Prelims 1992)
[A] Copper, zinc and iodine
[B] Zinc, copper and potassium
[C] Nitrogen, molybdenum and iodine
[D] Sulphur, copper and iron
Show Answer
Correct Answer: A [Copper, zinc and iodine]
Notes:
Copper, zinc and iodine are essential trace minerals. Potassium and sulphur are required in larger quantities and are not grouped with trace minerals. Human nitrogen requirements are met chiefly through dietary protein and other nitrogenous compounds.
