Biology objective questions and answers

Biology objective questions and answers
Questions and Answers for Biology Exams
Multiple Choice Questions With Answers - Objective Biology
1. The heart usually pumps blood with greater force in the old people than the young because
(a) The oxygen content per unit volume of the blood decreases
(b) The elasticity of the arteries decreases
(c) The elasticity of the arteries increases
(d) The nutrient content per unit of blood decrease
Ans. (b)

2. Contraction of muscle results from
(a) A contraction of myosin molecules
(b) Sliding of the actin and myosin filaments into each other
(c) The formation of peptide bonds that link actin and myosin
(d) Contraction of actin molecules
Ans. (b)

3. Typical ‘lub-dub’ sounds heard in heartbeat are due to
(a) Closing of bicuspid and tricuspid valves
(b) Closing of semi lunar valves
(c) Closure of bicuspid-tricuspid valves followed by semi lunar valves
(d) Blood under pressure through aorta
Ans. (d)


4. During contraction and relaxation of striated muscle fibre the length of band usually
(a) Increases
(b) Remains same sand does not change
(c) Decreases
(d) Decreases too much
Ans. (b)

5. In a normal person at rest the cardiac output, or amount of blood pumped per minute by the left ventricle, is approximately
(a) ½ liter
(b) 1 liter
(c) 2 liters
(d) 5 Liters
Ans. (d)

6. Which of the following ions are necessary in the chemical events of the muscle contraction?
(a) Sodium and Potassium
(b) Sodium and Magnesium
(c) Calcium and Magnesium
(d) Sodium and Calcium
Ans. (c)

7. Pulse beat is measured from
(a) artery
(b) Nerve
(c) Capillary
(d) Vein
Ans. (a)

8. Which one of following is called pace maker of the heart?
(a) SA node
(b) A V node
(c) Chordae tendinae
(d) A V septum
Ans. (a)

9. Which of the following features is NOT characteristic of ‘red’ skeletal muscles?
(a) Contract and relax very quickly
(b) High cytochrome contents
(c) Regeneration of ATP by oxidative osphorylation
(d) Regeneration of ATP by glycolysis
Ans. (d)

10. The circulatory system of a rabbit differs from that of a frog in that there is no
(a) Renal portal system in rabbit
(b) Hepatic portal system in rabbit
(c) Posterior vena cava in rabbit
(d) Dorsal aorta in rabbit
Ans. (a)

11. Hen’s disc is the other name of
(a) H-zone
(b) A-band
(c) I-band
(d) Z-line
Ans. (a)

12. A heart murmur indicates a defective
(a) Senatorial node
(b) Atrioventricular node
(c) Heart valve
(d) Pulmonary artery or aorta
Ans. (b)

13. When muscles get fatigued there is
(a) More ATP, no glycogen and no lactic acid
(b) Much ATP, more glycogen but much lactic acid
(c) Little ATP, and glycogen but much lactic acid
(d) Little ATP, more glycogen and little lactic acid
Ans. (c)


14. Grass stem elongates by the activity of
(a) Secondary meristem
(b) Intercalary meristem
(c) Apical meristem
(d) Primary meristem
Ans. (b)

15. An oxygen debt develops during
(a) Tetanus
(b) Sarcoplasmic release
(c) Anaerobic work
(d) Aerobic work
Ans. (c)


16. What is blood pressure?
(a) The pressure of blood on the heart muscle
(a) The pressure of blood exerted on the walls of arteries and veins
(c) The pressure of blood on the walls of veins only
(d) The pressure of blood on the walls of arteries only
Ans. (b)


17. Companion cells are usually seen associated with
(a) Fibres
(b) Parenchyma
(c) Xylem vessels
(d) Sieve tubes
Ans. (d)

18. The xylem and phloem are present on one radius the bundle is known as
(a) Conjoint
(b) Concentric
(c) Open
(d) Collateral
Ans. (a)

19. A portal system is that in which
(a) A vein begins from an organ and ends in heart
(b) An artery breaks up in an organ and restarts by the union of its capillaries
(c) The blood from gut is brought into kidneys before it is poured into heart
(d) A vein breaks up in an organ into capillaries and restart by their union as a new vein in the same organ
Ans. (d)

20. The color of lymph is
(a) White
(b) Pale yellow
(c) Colorless
(d) Milky
Ans. (c)


21. In which of the following phloem occurs in two patches?
(a) Bicollateral
(b) Collateral
(c) Amphicribral
(d) Amphivasal
Ans. (a)


22. In which organ the blood is stored?
(a) Spleen
(b) Liver
(c) Kidney
(d) Heart
Ans. (a)

23. Vascular bundles in the stem of Cucurbita are
(a) radial
(b) Collateral
(c) Bicollateral
(d) Concentric
Ans. (c)

24. Rh factor is named after
(a) Drosophila
(b) Monkey
(c) Rat
(d) Man
Ans. (b)


25. A collateral vascular bundle is one in which xylem and phloem strands are joined with phloem
(a) Toward inside
(b) On both sides of xylem
(c) All round xylem
(d) toward outside
Ans. (d)

26. The blood groups in man were discovered by
(a) Mendel
(b) Francis Nelson
(c) S. Miller
(d) Landsteiner
Ans. (d)

27. In a bicollateral vascular bundle
(a) Phloem is sandwiched between xylem
(b) Xylem is sandwiched between phloem
(c) Transverse splitting of one bundle into two equal parts
(d) Bundles, which cannot be identified
Ans. (b)


28. In root, xylem is referred as
(a) Polyarch
(b) Mesarch
(c) Endarch
(d) Exarch
Ans. (d)

29. Rh factor was discovered by
(a) William Harvey
(b) Landsteiner
(c) Robert Hook
(d) C. De Duve
Ans. (b)


30. Present between the blood capillaries and the cell membrane is a fluid through which gases, nutrients and metabolic wastes are exchanged between the blood and cell. This fluid is
(a) Lymph
(b) Plasma
(c) Serum
(d) Normal saline
Ans. (a)

31. Polyarch condition is seen in
(a) Monocot root
(b) Dicot root
(c) Dicot stem
(d) Monocot stem
Ans. (a)

32. Rh factor may be responsible for
(a) Turner’s syndrome
(b) AIDS
(c) Sickle cell anemia
(d) Efythroblastosis foetalis
Ans. (d)


33. In which of the following, growth is sub apical?
(a) Root
(b) Shoot
(c) Pedicle
(d) Petiole
Ans. (a)


34. Which one of the following blood groups belongs to the category of univers4alrecipient?
(a) A
(b) AB
(c) B
(d) O
Ans. (b)

35. Which one of the following is a biologically incompatible marriage?
(a) Rh positive boy and Rh positive girl
(b) Rh negative boy and Rh positive girl
(c) Rh negative boy and Rh negative
(d)-Rh positive boy and Rh negative girl
Ans. (d)


36. Monocot root differs from dicot root in having
(a) Scattered vascular bundles
(b) Well developed pith
(c) Radically arranged vascular bundles
(d) Open vascular bundles
Ans. (b)

37. Mendel was born in
(a) Australia
(b) Germany
(c) Britain
(d) Czechoslovakia
Ans. (d)

38. In dicot root
(a) Vascular bundles are arranged in ring and have cambium
(b) Xylem and phloem are radially arranged
(c) Xylem is always endarch
(d) Vascular bundles are scattered
Ans. (b)

39. G. Mendel died in
(a) 1884
(b) 1890
(c) 1900
(d) 1926
Ans. (a)

40. Centripetal xylem is present in
(a) Dicot root
(b) Monocot stem
(c) Branches of stem
(d) Dicot stem
Ans. (a)

41. MENDEL studied seven contrasting characters for his breeding experiment with Pisum -sativum, which of the following character did he not use?
(a) Pod colour
(b) Pod shape
(c) Leaf shape
(d) Plant height
Ans. (c)

42. Collenchymatous hypodermis is present in
(a) Dicot stem
(b) Monocot as well as in dicot stems
(c) Monocot stem
(d) Monocot root
Ans. (a)


43. Genotype means;
(a) genetic composition of the individual
(b) genetic composition of the germ cell
(c) genetic composition of plastids
(d) genetic composition of an organ
Ans. (a)

44. Mendel’s laws apply only when
(a) F1 in monohybrid cross shows two types of individuals
(b) the characters are linked
(c) parents are pure breeding
(d) first pair of contrasting character is dependent upon other pairs
Ans. (c)

45. The lacunae in the vascular bundles of monocot stems is
(a) A mucilage canal
(b) Lysigenous water cavity
(c) A large sized vessel
(d) Metaxylem
Ans. (b)


46. Vascular bundle in dicot roots is
(a) Conjoint
(b) Radial
(c) Collateral
(d) Bicollateral
Ans. (b)

47. When an individual is having both the alleles of contrasting characters it is said to be
(a) Heterozygous
(b) Dioecious
(c) Monoecious
(d) Linked genes
Ans. (a)

48. Well-developed pith is found in
(a) Monocot stem and dicot root
(b) Monocot root and dicot stem
(c) Dicot root and dicot stem
(d) Monocot root and monocot stem
Ans. (b)


49. Phloem parenchyma is absent in
(a) Dicot leaf
(b) Monocot stem
(c) Dicot stem
(d) Dicot root
Ans. (b)

50. If a plant is heterozygous for tallness, the F2 generation has both tall and dwarf plants. This proves the principle of
(a) Dominance
(b) Segregation
(c) Independent assortment
(d) incomplète dominance
Ans. (b)