Q7. One of the major components of cell wall of most fungi is :
Correct Answer: (a)
Fungal cell walls are made of chitin.
Q8. The coconut water from tender coconut represents :
Correct Answer: (d)
Tender coconut water is free-nuclear endosperm.
Q9. A typical fat molecule is made up of :
Correct Answer: (b)
A triglyceride consists of one glycerol backbone esterified to three fatty acids.
Q10. Mitochondria and chloroplast are : (a) semi-autonomous organelles. (b) formed by division of pre-existing organelles and they contain DNA but lack protein synthesizing machinery. Which one of the following options is correct ?
Correct Answer: (c)
Organelles have their own DNA and ribosomes (machinery).
Q11. Which of the following is not a feature of the plasmids ?
Correct Answer: (d)
Plasmids are double-stranded DNA molecules.
Q12. Which one of the following statements is not true ?
Correct Answer: (a)
Tapetum provides nourishment; the endothecium helps in dehiscence.
Q13. In which of the following, all three are macronutrients ?
Correct Answer: (d)
Nitrogen and phosphorus are macronutrients; official key marks this as a bonus/4.
Q14. Asthma may be attributed to :
Correct Answer: (b)
Asthma is an allergic response causing bronchospasm.
Q15. Which of the following features is not present in Periplaneta americana ?
Correct Answer: (b)
Insects have determinate and spiral cleavage.
Q16. Pick out the correct statements : (a) Haemophilia is a sex-linked recessive disease. (b) Down's syndrome is due to aneuploidy. (c) Phenylketonuria is an autosomal recessive gene disorder. (d) Sickle cell anaemia is an X - linked recessive gene disorder.
Correct Answer: (d)
Sickle cell is autosomal, not X-linked. a, b, c are correct.
Q17. A tall true breeding garden pea plant is crossed with a dwarf true breeding garden pea plant. When the F1 plants were selfed the resulting genotypes were in the ratio of :
Correct Answer: (a)
The genotypic ratio of a monohybrid cross is 1:2:1.
Q18. In mammals, which blood vessel would normally carry largest amount of urea ?
Correct Answer: (c)
Urea is produced in the liver and exits via the hepatic vein.
Q19. The taq polymerase enzyme is obtained from :
Correct Answer: (a)
Taq polymerase is isolated from the thermophilic bacterium Thermus aquaticus.
Q20. Proximal end of the filament of stamen is attached to the :
Correct Answer: (d)
Filaments attach to the thalamus or the petals in epipetalous flowers.
Q21. Which of the following most appropriately describes haemophilia ?
Correct Answer: (b)
Haemophilia is an X-linked recessive genetic disorder.
Q22. A complex of ribosomes attached to a single strand of RNA is known as :
Correct Answer: (a)
A string of ribosomes on mRNA is called a polysome or polyribosome.
Q23. Spindle fibres attach on to :
Correct Answer: (b)
Spindle fibres attach to the kinetochore protein discs.
Q24. Joint Forest Management Concept was introduced in India during :
Correct Answer: (c)
JFM was introduced by the Govt. of India in the 1980s.
Q25. Gause’s principle of competitive exclusion states that :
Correct Answer: (c)
Gause's principle states that two species competing for the same limiting resource cannot coexist.
Q26. Identify the correct statement on 'inhibin' :
Correct Answer: (b)
Inhibin is produced by granulose cells (females) or Sertoli cells (males) and inhibits FSH.
Q27. In a chloroplast the highest number of protons are found in :
Correct Answer: (b)
Protons accumulate in the lumen of thylakoids during light reaction.
Q28. Which of the following features is not present in the Phylum - Arthropoda ?
Correct Answer: (c)
Parapodia are found in Annelida, not Arthropoda.
Q29. Select the incorrect statement :
Correct Answer: (c)
Gonadotropins (LH/FSH) increase, not decrease, during the follicular phase.
Q30. Microtubules are the constituents of :
Correct Answer: (b)
Microtubules make up the cytoskeleton of spindle fibers, cilia, and centrioles.
Q31. Which part of the tobacco plant is infected by Meloidogyne incognita ?
Correct Answer: (d)
This nematode infects the roots of tobacco plants.
Q32. Which of the following approaches does not give the defined action of contraceptive ?
(1) Barrier methods
prevent fertilization
(2) Intra uterine devices
increase phagocytosis of sperms, suppress sperm motility
(3) Hormonal contraceptives
Prevent/ retard entry of sperms, prevent ovulation
(4) Vasectomy
prevents spermatogenesis
Correct Answer: (d)
Vasectomy prevents sperm transport, not the production of sperm (spermatogenesis).
Q33. Which of the following is wrongly matched in the given table ?
Microbe
Product
Application
(1) Trichoderma
Cyclosporin A
immunosuppressant
(2) Monascus
Statins
lowering cholesterol
(3) Streptococcus
Streptokinase
removal of clot
(4) Clostridium
Lipase
removal of oil stains
Correct Answer: (d)
Lipase is produced by Candida or Aspergillus; Clostridium is used for Butyric acid.
Q34. Analogous structures are a result of :
Correct Answer: (b)
Analogous organs arise from convergent evolution due to similar environments.
Q35. Which one of the following is a characteristic feature of cropland ecosystem ?
Correct Answer: (b)
Artificial ecosystems like croplands have low genetic diversity.
Q36. Which of the following pairs of hormones are not antagonistic (having opposite effects) to each other ?
Correct Answer: (d)
Relaxin and Inhibin do not have antagonistic functions.
Q37. Which of the following characteristic features always holds true for the corresponding group of animals ?
(1) Cartilaginous endoskeleton
Chondrichthyes
(2) Viviparous
Mammalia
(3) Mouth with upper/lower jaw
Chordata
(4) 3-chambered heart
Reptilia
Correct Answer: (a)
Chondrichthyes always have cartilaginous skeletons. Other groups have exceptions (e.g., Platypus is oviparous).
Q38. In higher vertebrates, the immune system can distinguish self-cells and non-self. If this property is lost due to genetic abnormality and it attacks self-cells, then it leads to :
Correct Answer: (c)
Loss of self-recognition leads to auto-immune diseases.
Q39. Name the chronic respiratory disorder caused mainly by cigarette smoking :
Correct Answer: (a)
Emphysema is a chronic disorder caused by cigarette smoking.
Q40. Changes in GnRH pulse frequency in females is controlled by circulating levels of :
Correct Answer: (a)
Ovarian steroids provide feedback to the hypothalamus.
Q41. Which of the following guards the opening of hepatopancreatic duct into the duodenum ?
Correct Answer: (d)
The Sphincter of Oddi regulates the flow of bile and pancreatic juice into the duodenum.
Q42. Fertilization in humans is practically feasible only if :
Correct Answer: (b)
Transport must be simultaneous to the ampullary-isthmic junction.
Q43. Match the terms in Column I with their description in Column II and choose the correct option :
(a) Dominance
(i) Many genes govern a single character
(b) Codominance
(ii) In a heterozygous organism only one allele expresses itself
(c) Pleiotropy
(iii) In a heterozygous organism both alleles express themselves fully
(d) Polygenic inheritance
(iv) A single gene influences many characters
Correct Answer: (b)
Correct biological definitions of inheritance patterns.
Q44. Which is the National Aquatic Animal of India ?
Correct Answer: (b)
The Gangetic River Dolphin is the national aquatic animal.
Q45. Which of the following is required as inducer(s) for the expression of Lac operon ?
Correct Answer: (c)
Lactose acts as the inducer for Lac operon.
Q46. The standard petal of a papilionaceous corolla is also called :
Correct Answer: (c)
The largest posterior petal is the Vexillum (Standard).
Q47. In meiosis crossing over is initiated at :
Correct Answer: (a)
Crossing over occurs during the Pachytene stage of Prophase I.
Q48. Which of the following statements is wrong for viroids ?
Correct Answer: (d)
Viroids have RNA of low molecular weight.
Q49. Which one of the following statements is wrong ?
Correct Answer: (c)
Eubacteria are 'true' bacteria, not false bacteria.
Q50. In context of Amniocentesis, which of the following statement is incorrect ?