Q- A DNA molecule in which both strands have radioactive thymidine is permitted to replicate in an environment that contains non-radioactive thymidine. What is the right number of DNA molecules which possess some radioactive thymidine post three duplications?
(a) one such molecule
(b) two such molecules
(c) four such molecules
(d) eight such molecules
Answer: (b)
Q- If the DNA strand has nitrogenous base sequence ATTGCC, the mRNA will have?
(a) ATTGCA
(b) UGGACC
(c) UAACGG
(d) ATCGCC
Answer: (c)
Q- The type of coiling in DNA is
(a) Zig-zag
(b) Left-handed
(c) Opposite
(d) Right-handed
Answer: (d)
Q- Tryptophan synthetase of E.coli, a typical bifunctional oligomeric enzyme consists of
(a) a protein A and one subunit A
(b) a protein designated A
(c) two proteins designated A and B
(d) a protein designated B
Answer: (c)
Q- This statement about enzymes is true
(a) enzymes accelerate reactions by lowering the activation energy
(b) enzymes are proteins whose three-dimensional form is key to their function
(c) enzymes do not alter the overall change in free energy for a reaction
(d) all of these
Answer: (d)
Q- The enzyme COX-1 is vital for human health in this way:
(a) it is a chemical derivative of aspirin
(b) catalyzes the hormone-production which maintains the stomach lining
(c) critical for the biosynthesis of DNA
(d) helps in the transportation of carbon dioxide in the blood
Answer: (b)
Q- The hot spots of biodiversity are characterized by:
(a) low endemicity and low threat of extinction
(b) low endemicity and high threat of extinction
(c) high endemicity and low threat of extinction
(d) high endemicity and high threat of extinction
Answer: (d)
Q- Presence of plants organised into well defined vertical layers based on their heights can be best observed in
(a) grassland
(b) tropical savannah
(c) tropical rain forest
(d) temperate forest
Answer: (c)
Q- Which of these is related to Ex-situ conservation of threatened plants and animals?
(a) Biodiversity hotspots
(b) Wildlife safari parks
(c) Amazon rainforest
(d) Himalayan region
Answer: (b)
Q- The region of biosphere reserve that is protected legally, where no human activity takes place is known as
(a) transition zone
(b) buffer zone
(c) core zone
(d) restoration zone
Answer: (c)
Q- Pick the correct match
(a) Stratification – Population
(b) Aerenchyma – Opuntia
(c) Age Pyramid – Biome
(d) Parthenium hysterophorus – a threat to biodiversity
Answer: (d)
Q- The National aquatic animal of India is
(a) Sea horse
(b) River Dolphin
(c) Blue whale
(d) Gangetic shark
Answer: (b)
Q- The nature of an enzyme is
(a) Lipid
(b) Vitamin
(c) Carbohydrate
(d) Protein
Answer: (d)
Q- In alcoholism, this enzyme is elevated
(a) acid phosphatase
(b) hepatitis
(c) serum glutamate pyruvate transaminase
(d) glutamyl transpeptidase
Answer: (d)
Q- With regards to enzyme action, this statement is incorrect
(a) Malonate is a competitive inhibitor of succinic dehydrogenase
(b) the substrate binds with the enzyme at its active site
(c) the non-competitve inhibitor binds the enzyme at a site distinct from that binding the substrate
(d) addition of a lot of succinates does not reverse the inhibition of succinic dehydrogenase by malonate
Answer: (d)
Q- What is the count of genes that determine the synthesis of one enzyme?
(a) One
(b) Four
(c) Eight
(d) Sixteen
Answer: (a)
Q- This enzyme was first isolated and purified in the form of crystals
(a) Urease
(b) pepsin
(c) Amylase
(d) Ribonuclease
Answer: (a)
Q- Macromolecule chitin is
(a) a simple polysaccharide
(b) sulphur containing polysaccharide
(c) phosphorous containing polysaccharide
(d) nitrogen containing polysaccharide
Answer: (d)
Q- Enzyme-driven metabolic pathways can be made more efficient by
(a) grouping enzymes into multienzyme free-floating complexes
(b) concentrating enzymes with specific cellular compartments
(c) fixing enzymes into membranes so they are adjacent to each other
(d) all of these
Answer: (d)
Q- DNA fingerprinting recognizes the differences in
(a) satellite DNA
(b) bulk DNA
(c) Repetitive DNA
(d) both (a) and (c)
Answer: (d)
Q- This force can stabilize a DNA double-helix
(a) Hydrophilic sugar-phosphate groups are found on the exterior of the helix where interaction with water occurs
(b) Hydrophobic bases are present in the interior of the helix, each base-pair is stabilized by the same number of hydrogen bonds
(c) covalent base stacking interactions may take place between neighbouring bases within the same strand in the helix
(d) non-covalent N-glycosidic bonds may form between nitrogenous bases in opposite strands in the helix
Answer: (a)
Q- In this type of DNA replication, of the two newly formed molecules, one is purely a new one and the other is an old one
(a) dispersive
(b) conservative
(c) semiconservative
(d) both (b) and (c)
Answer: (c)
Q- The process of DNA replication is affected by an enzyme known as
(a) Mutase
(b) Ligase
(c) Polymerase I
(d) Ribonuclease
Answer: (c)
Q- In DNA, the enzyme which breaks the H2 bonds is
(a) Ligase
(b) Helicase
(c) Topoisomerase
(d) Polymerase
Answer: (b)
Q- The total DNA comprises what amount of cytoplasmic DNA in cells?
(a) 95-99%
(b) 65-75%
(c) 45-50%
(d) 1-5%
Answer: (d)
Q- The bases are held together in a DNA double helix by hydrogen bonds. These bonds are
(a) Ionic bonds
(b) Covalent bonds
(c) Non-covalent bonds
(d) Van der Waals forces
Answer: (c)
Q- The most important reason for biodiversity loss in today’s age is
(a) over-exploitation
(b) co-extinctions
(c) alien species invasions
(d) fragmentation and habitat loss
Answer: (d)
Q- Biodiversity loss can lead to everything except this
(a) increased resistance to the environmental perturbance
(b) a decline in plant production
(c) increased variability in water use
(d) increased variability in pest and disease cycle
Answer: (a)
Q- Which of these is not a reason accounting for greater biodiversity of tropics?
(a) more niche specialization
(b) availability of more solar energy
(c) more time for species diversification
(d) large seasonal variations in environmental factors
Answer: (d)
Q- The main difference between the ‘Sixth extinction’ and the previous five extinctions is that, the sixth extinction
(a) mainly affects plants
(b) mainly occurs on islands
(c) occurs at a faster rate
(d) is exclusive of human activities
Answer: (c)
