NU Singapore Entrance Exam Biology Solved Paper

University Entrance Examination Biology Solved Paper

National University of Singapore

Nanyang Technological University

1. Which of the following statements is incorrect?

(a) DNA provides the genetic code for the synthesis of proteins in all organisms.
(b) In 1983, James Crick and Francis Watson identified and described the double helix structure of DNA.
(c) In the DNA helix, purines pair with pyrimidines via hydrogen bonding.
(d) The two chains of polynucleotides in a DNA molecule are anti-parallel and complement each other.

(b) In 1983, James Crick and Francis Watson identified and described the double helix structure of DNA.

2. Adenine comprised 40 % of the nitrogenous bases in the DNA of cells from a bacterial clone. What was the percentage of guanine in the DNA?

(a) 10 %
(b) 20 %
(c) 40 %
(d) 80 %

(a) 10 %

3. All cells of an earthworm have the following components except

(a) mitochondria.
(b) nuclei.
(c) plasma membranes.
(d) cell walls.

(d) cell walls.

4. Which of the following statements is correct?

(a) Proteins are simple molecules.
(b) Carbohydrates are the major molecules from which muscle cells of animals are constructed.
(c) Amino acids contain carbon, hydrogen, oxygen, nitrogen and, also, sulphur and phosphorous.
(d) Lipids are not a source of energy.

5. All the following can be found in prokaryotic cells except

(a) cell membranes.
(b) cytoplasma.
(c) pili.
(d) nuclei.

(d) nuclei.

6. Chlorophylls are plant pigments that absorb light optimally in the

(a) green and yellow wavelengths.
(b) green and blue wavelengths.
(c) blue and red wavelengths.
(d) blue and infrared wavelengths.

7. Which of the following plants take up carbon dioxide for photosynthetic reactions during the night?

(a) Hibiscus and lily plants.
(b) Spinach and cucumber plants.
(c) Corn and sugar cane plants.
(d) Cactus and pineapple plants.

(d) Cactus and pineapple plants.

8. Which of the following is a polysaccharide found in human muscle cells?

(a) Myoglobin.
(b) Collagen.
(c) Glycogen.
(d) Amylose.

9. Which of the following statements is true of all enzymes?

(a) All enzymes are denatured at 60 oC and higher.
(b) The active sites of all enzymes can only bind to only one type of substrate.
(c) All enzymes lower the activation energy of the reaction.
(d) All enzymes catalyze the degradation of large molecules into smaller moieties.

10. Monocotyledons are distinguished by all the following traits except that

(a) they have a single seed leave.
(b) their flowers have a three-part symmetry.
(c) the veins on their leaves are not arranged in a net pattern.
(d) they include plants like orchids.

(a) they have a single seed leave.

11. The muscular system of all vertebrates does not include

(a) smooth muscle cells.
(b) cardiac muscle cells.
(c) skeletal muscle cells.
(d) epithelial muscle cells.

(d) epithelial muscle cells.

12. Which of the following statements is incorrect?

(a) Most of the energy in an animal comes from the aerobic breakdown of carbohydrates.
(b) In all respiratory systems of animals, the exchange of gases needs a lot of energy.
(c) In the respiratory systems of animals, gases cannot be transported in the gaseous form.
(d) Seals have more heamoglobin than humans.

(b) In all respiratory systems of animals, the exchange of gases needs a lot of energy.

13. A woman, who is a carrier of haemophilia, had phenotypically normal parents and is married to a man without the recessive haemophilia gene. Which of the following statements is correct?

(a) All of her sons are haemophiliacs.
(b) All of her daughters are haemophiliacs.
(c) Her father was a carrier of haemophilia.
(d) Her mother was a carrier of haemophilia.

(d) Her mother was a carrier of haemophilia.

14. What is a codon?

(a) A specific group of three sequential bases of mRNA that recognizes and attracts specific amino acids using tRNA as an intermediary.
(b) A specific group of three sequential bases of DNA that recognizes and attracts specific amino acids using mRNA as an intermediary.
(c) A fragment of the DNA molecule which codes for a protein.
(d) A fragment of the DNA molecule which can undergo mutation.

(a) A specific group of three sequential bases of mRNA that recognizes and attracts specific amino acids using tRNA as an intermediary.

15. Which of the following is an autotroph?

(a) Shitake mushrooms.
(b) A fish.
(c) A virus.
(d) An apple tree.

(d) An apple tree.

16. The C4-pathway of primary photosynthetic fixation is an adaptation of plants to grow in

(a) the desert.
(b) hot and dry conditions.
(c) hot and high light conditions.
(d) All of the above conditions.

(d) All of the above conditions.

17. Most of our important crop plants come from the ----- family of plants.

(a) grass
(b) orchid
(c) rose
(d) bromeliad

(a) grass.

18. The ----- is considered the most intelligent invertebrate.

(a) grasshopper
(b) mosquito
(c) squid
(d) crab

19. Impulses can travel very rapidly along the nerves in our leg muscles because

(a) there is a high concentration of sodium ions inside these nerve cells.
(b) there is a high concentration of chloride ions inside these nerve cells.
(c) the nerve cells contain a high concentration of calcium ions.
(d) the nerves are insulated by thick myelin sheaths.

(d) the nerves are insulated by thick myelin sheaths.

20. You have to weigh out 155 mg of sodium bicarbonate salt for an experiment on photosynthesis. Your weighing machine shows weight in terms of g (grams) only. How many g of sodium bicarbonate powder do you need to weigh out?

(a) 155 g
(b) 15.5 g
(c) 1.55 g
(d) 0.155 g

(d) 0.155 g

21. In peas, tall stem length is dominant over short stem length. What genotypic ratio would you expect in the offsprings of a cross between a heterozygous tall plant and a homozygous short plant?

(a) 3 homozygous tall : 1 homozygous short.
(b) 1 homozygous tall : 3 homozygous short.
(c) 1 heterozygous tall : 1 homozygous short: 2 heterozygous short.
(d) 1 heterozygous tall : 2 homozygous short: 1 heterozygous short.

22. Adjacent plant cell walls are cemented by the

(a) cutin layer.
(b) primary wall
(c) secondary wall.
(d) middle lamella.

(d) middle lamella.

23. Which of the following class of compounds are generally hydrophobic?

(a) Carbohydrates.
(b) Lipids.
(c) Nucleic acids
(d) Proteins.

(b) Lipids.

24. Which of the following transport processes in cells requires ATP?

(a) Simple diffusion.
(b) Facilitated diffusion.
(c) Osmosis.
(d) Active Transport.

(d) Active Transport.

25. Mary wants to determine the effect of temperature on the activity of an enzyme she isolated from a plant growing in her garden. She can expect that the activity of the enzyme would

(a) increase constantly as temperature increases.
(b) decrease constantly as temperature increases.
(c) increase to a certain level, then decrease, as temperature increases.
(d) increase, then decrease, and increase again as temperature increases.

26. Which of the following is produced during both the cyclic and non-cyclic transport of electrons of photosynthesis?

(a) water
(b) ATP
(c) oxygen
(d) NADPH

(b) ATP.

27. During photosynthesis, carbon dioxide is fixed by bonding to

(a) glucose.
(b) glyceraldehyde-3-phosphate.
(c) ribulose-1,5-bisphosphate.
(d) ribulose-1,5-bisphosphate carboxylase.

28. Which of the following conditions favours photorespiration in plants?

(a) Darkness.
(b) Plants growing near to each other.
(c) Hot and dry conditions.
(d) Cool days.

29. Which of the following statements is incorrect?

(a) Stomata are found on both leaves and green stems.
(b) Stomata allow CO2 and not O2 to pass through.
(c) Stomata are specialized pores on plants.
(d) Stomata close when a plant is subjected to drought.

(b) Stomata allow CO2 and not O2 to pass through.

30. Bacteriophages are

(a) bacteria that infect viruses.
(b) bacteria that are parasitic.
(c) viruses that infect bacteria.
(d) viruses that are parasitic.

31. A restriction enzyme, used in recombinant DNA technology, is most likely to

(a) join DNA fragments together.
(b) cut DNA into fragments with sticky ends.
(c) transfer a plasmid into a bacterial cell.
(d) stimulate cell division in transformed cells.

(b) cut DNA into fragments with sticky ends.

32. Another term for neurons is

(a) neutron.
(b) neutral sex cells.
(c) blood cells.
(d) nerve cells.

(d) nerve cells.

33. Which of the following statements is correct?

(a) Sexual reproduction is biologically an inexpensive process.
(b) The reproductive systems of most terrestrial animals depend on external fertilization.
(c) Many animal species do not use seasonal changes to coordinate the timing of their reproductive systems.
(d) Sexual reproduction is the dominant form of reproduction among animals.

(d) Sexual reproduction is the dominant form of reproduction among animals.

34. The definition of a hermaphrodite is that of

(a) any organism that produces both eggs and sperm.
(b) a human male who has undergone a sex operation to be changed into a female.
(c) any organism that releases a lot of eggs into its own mouth.
(d) any organism that shows a high rate of haemoglobin production.

(a) any organism that produces both eggs and sperm.

35. Which of the following statements is true of fungi?

(a) Fungi are autotrophs.
(b) The food-absorbing part of a fungus is the mycelium.
(c) A mushroom is not classified as a fungus.
(d) Fungi are always harmful to the human race.

(b) The food-absorbing part of a fungus is the mycelium.

36. Each of the following is a function of epithelial tissue except

(a) movement.
(b) protection.
(c) secretion.
(d) sensory ability.

(a) movement.

37. Calcium in the muscle cells attaches to

(a) the neurotransmitter.
(b) actin.
(c) myosin.
(d) troponin.

(d) troponin.

38. Mammals are unique among all vertebrates because they

(a) do not lay eggs.
(b) have hair.
(c) are warm-blooded.
(d) have a cartilaginous skeleton.

(b) have hair.

39. PCR is a technique used to

(a) amplify a region of DNA.
(b) chop up a source of DNA.
(c) transfer genes.
(d) create clone libraries.

(a) amplify a region of DNA.

40. Each of the following is a function of the Golgi complex except

(a) collection of molecules.
(b) distribution of molecules.
(c) synthesis of molecules.
(d) packaging of molecules.

41. Which of the following refers specifically to the transport of water?

(a) Energy transfer.
(b) Osmosis.
(c) Active transport.
(d) Diffusion.

(b) Osmosis.

42. Photosynthetic carbon fixation requires the expenditure of ATP molecules. This ATP is generated by

(a) formation of glucose during the light-independent reactions.
(b) replenishment of the photosynthetic pigment.
(c) chemiosmotic synthesis during the light-dependent reactions.
(d) all of the above.

43. Which of the genetic diseases stated below is sex-linked?

(a) Cystic fibrosis.
(b) Haemophilia.
(c) Hypercholesterolemia.
(d) Tay-Sachs disease.

(b) Haemophilia.

44. According to the Watson-Crick model of DNA, if you know that the base-sequence of one strand is AATTCG, the sequence of the complementary strand must be

(a) AATTCG.
(b) TTGGAC.
(c) TTAAGG.
(d) TTAAGC.

(d) TTAAGC.

45. DNA makes RNA by

(a) repair.
(b) replication.
(c) transcription.
(d) translation.

46. In creating recombinant DNA, the sticky ends of source DNA fragments are joined to the sticky ends of ----- produced by the cutting up of a circular bacterial chromosome.

(a) antibiotics
(b) clones
(c) plasmids
(d) restriction enzymes

47. A version of DNA that is made from processed RNA is called

(a) a plasmid.
(b) a probe.
(c) cDNA.
(d) mDNA.

48. The transfer of working copies of genes from normal, healthy individuals to afflicted individuals is known as

(a) a piggyback vaccine.
(b) the Human Genome Project.
(c) human gene therapy.
(d) DNA fingerprinting.

49. Prokaryotes, including bacteria, lack

(a) an organized nucleus.
(b) cells.
(c) cytoplasm.
(d) DNA.

(a) an organized nucleus.

50. Which of the following is not an arthropod?

(a) Butterfly.
(b) Crayfish.
(c) Earthworm.
(d) Spider.

51. Unlike the sponges and flatworms, vertebrates have a

(a) backbone.
(b) coelom.
(c) exoskeleton.
(d) nervous system.

(a) backbone.

52. Each of the following is a final product of human digestion except

(a) amino acids.
(b) fatty acids.
(c) free sugars.
(d) starch.

(d) starch.

53. Schwann cells, which envelop the axon at intervals along the length, act as

(a) dendrites.
(b) electrical insulators.
(c) nerves.
(d) tracts.

(b) electrical insulators.

54. Which of the following does not promote biodiversity?

(a) Introduction of exotic species.
(b) Larger size of an ecosystem.
(c) Longer growing season.
(d) Climatic stability.

(a) Introduction of exotic species.

55. The path of energy in complex ecosystems with animals often feeding at various trophic levels is called a

(a) community.
(b) food chain.
(c) food web.
(d) mineral cycle.

56. Cristae are found in which of the following?

(a) Chloroplasts.
(b) Mitochondria.
(c) Nuclei.
(d) Lysosomes.

(b) Mitochondria.

57. Darwin believed that the major driving force in evolution was

(a) molecular biology.
(b) natural selection.
(c) divine creation.
(d) scientific creation.

(b) natural selection.

58. The key advantage of multicellularity is that

(a) it allows the organism to be motile.
(b) it allows the organism to reproduce sexually.
(c) it allows the organism to photosynthesize.
(d) it allows special tissues to be formed within the organism.

(d) it allows special tissues to be formed within the organism.

59. A mass of fungal filaments is called a

(a) colony.
(b) hyphae.
(c) mycelium.
(d) mycorrhizae.

60. About 90 % of the water taken up by roots is lost to the atmosphere. Which of the following structure accounts for the greatest loss of water in plants?

(a) Stomata.
(b) Epidermes.
(c) Cuticles.
(d) Lenticels.

(a) Stomata.