31. Which one of the following is not a downy mildew fungus?
[A] Bremia Lectuca
[B] Uncinula Necator
[C] Sclerospora Graminocola
[D] Plasmopara Viticola
Show Answer
Correct Answer: B [Uncinula Necator]
Notes:
Uncinula necator is a fungus that causes powdery mildew of grape. The fungus is believed to have originated in North America.
32. Where was the first reported rusting of coffee in 1868?
[A] Brazil
[B] Ceylon
[C] India
[D] Indonesia
Show Answer
Correct Answer: B [Ceylon]
Notes:
Rusting of coffee was first reported in Sri Lanka (then Ceylon) in 1868. Coffee leaf rust is caused by the fungus Hemileia vastatrix.
33. Which one has a poison gland?
[A] Male platypus
[B] Scoliodon
[C] Rat snake
[D] Wall lizard
Show Answer
Correct Answer: A [Male platypus]
Notes:
The male platypus has a spur on the inner side of each ankle that is connected to a poison gland located on top of the thighbone.
34. Which of the following cells of the testis secrete testosterone?
[A] sertoli cells
[B] cells of germinal epithelium
[C] cells of Leydig or interstitial cells
[D] secondary spermatocytes
Show Answer
Correct Answer: C [cells of Leydig or interstitial cells]
Notes:
Leydig or interstitial cells of the testis secrete testosterone. It is present outside the seminiferous tubules in the interstitial spaces.
35. Which of the following female reproductive organs produces female gametes?
[A] Ovaries
[B] Uterus
[C] Fallopian tubes
[D] Vagina
Show Answer
Correct Answer: A [Ovaries]
Notes:
Ovaries are the female reproductive organs that produce female gametes. It is also responsible for producing various hormones.
36. Which organ is affected by Japanese encephalitis?
[A] brain and spinal cord
[B] lungs
[C] liver and pancreas
[D] heart
Show Answer
Correct Answer: A [brain and spinal cord]
Notes:
The Brain and spinal cord organs are affected by Japanese encephalitis. This is a viral infection caused by infected mosquitoes in Asia and the western Pacific.
37. Leptospirosis is a disease caused by ____:
[A] Fungus
[B] Protozoa
[C] Virus
[D] Bacteria
Show Answer
Correct Answer: D [Bacteria]
Notes:
Leptospirosis is a bacterial disease caused by corkscrew-shaped bacteria called Leptospira. Signs and symptoms can range from none to mild such as headaches, muscle pains, and fevers; to severe with bleeding from the lungs or meningitis. If the infection causes the person to turn yellow, have kidney failure and bleeding, it is then known as Weil’s disease.
38. Which of the following diseases are not caused by smog?
[A] Breathing problem
[B] Throat cancer
[C] Skin cancer
[D] Rickets
Show Answer
Correct Answer: D [Rickets]
Notes:
Rickets is the softening and weakening of bones in children, usually because of an extreme and prolonged vitamin D deficiency. Vitamin D promotes the absorption of calcium and phosphorus from the gastrointestinal tract.
39. What is thick vein present in the middle of the leaf called?
[A] Leaf venation
[B] Parallel venation
[C] Midrib
[D] Reticulate
Show Answer
Correct Answer: C [Midrib]
Notes:
A thick vein seen in the middle of the leaf is called the midrib. Pinnately veined leaves have one large central vein, called the midrib, which extends from the base of the blade to its tip. Other large veins branch off on each side of the midrib. The leaves of beech, birch, and elm trees have such a vein pattern.
40. Which of the following bacterium causes crown gall disease in plants?
[A] Agrobacterium tumefaciens
[B] Pseudomonas fluorescens
[C] Bacillus thurigiensis
[D] None of the above
Show Answer
Correct Answer: A [Agrobacterium tumefaciens]
Notes:
Crown gall is a disease caused by the bacterium Agrobacterium tumefaciens (synonym Rhizobium radiobacter), which enters the plant through wounds in roots or stems and stimulates the plant tissues to grow in a disorganized way, producing swollen galls. As the disease progresses, plants lose vigour and may eventually die. In science of Biotechnology, it is considered as natural engineer.
