31. Syphilis is a bacterial infection usually spread by __
[A] Sexual contact
[B] Wound infection
[C] Air-borne droplets
[D] None of these
Show Answer
Correct Answer: A [Sexual contact]
Notes:
Syphilis is a bacterial infection mostly spread by sexual contact. It is caused by Treponema pallidum bacteria.
32. Sugar crops to produce __
[A] biomethane
[B] bioethanol
[C] biobutanol
[D] None of these
Show Answer
Correct Answer: B [bioethanol]
Notes:
Bioethanol is produced by fermentation of residues from corn, potatoes, cereals, sugar beets, sugarcane and vegetables.
33. Which one of the following is commonly known as Pond Silk?
[A] Yeast
[B] Rhizopus
[C] Ulothrix
[D] Spirogyra
Show Answer
Correct Answer: D [Spirogyra]
Notes:
Pond silk is the common name of Spirogyra (algae) because it is very slimy in shape. It is also known as pond silk, water silk, pond scum or mermaid’s trees because of its bright green silky appearance. Its filaments shine like silk due to the presence of mucilage and spiral shaped chloroplast.
34. What are female gametes called as?
[A] Zygote
[B] Sperms
[C] Embryo
[D] Ova
Show Answer
Correct Answer: D [Ova]
Notes:
Female gametes are also called eggs or ova. They are created during the cellular reproduction process known as meiosis. The resulting gamete cell is a haploid cell. When the two haploid cells, the egg and sperm, fuse together during fertilization, the result is a diploid cell called a zygote.
35. The narrowest and most numerous tubes of lungs are termed as ____:
[A] Bronchus
[B] Hilum
[C] Bronchioles
[D] Alveoli
Show Answer
Correct Answer: C [Bronchioles]
Notes:
The respiratory bronchioles are the narrowest airways of the lungs, one fiftieth of an inch across. The bronchi divide many times before evolving into the bronchioles. The bronchioles deliver air to the exchange surfaces of the lungs.
36. Muscle fatigue occurs due to accumulation of ____:
[A] Carbonic Acid
[B] Lactic Acid
[C] ATP
[D] ADP
Show Answer
Correct Answer: B [Lactic Acid]
Notes:
Muscle fatigue refers to the decline in muscle force generated over time. Several factors contribute to muscle fatigue, the most important being lactic acid accumulation. Lactic acid is formed and accumulated in the muscle under conditions of high energy demand, rapid fluctuations of the energy requirement and insufficient supply of O2.
37. Brain receives and sends signals in the form of ____:
[A] Electrical impulses
[B] Magnetic impulses
[C] Mechanical impulses
[D] Chemical impulses
Show Answer
Correct Answer: A [Electrical impulses]
Notes:
The human brain sends messages to other parts of the body through a network of connecting wires (neurons) called the nervous system. Neurons carry messages in the form of electrical signals called nerve impulses. The human brain contains about 100 billion neurons.
38. Which of the following is a communicable disease?
I. Malaria
II. Tuberculosis
III. Measles
[A] Only II
[B] Only III
[C] Both I and III
[D] Both II and III
Show Answer
Correct Answer: D [Both II and III]
Notes:
Malaria is a life-threatening mosquito-borne blood disease caused by a Plasmodium parasite. It is transmitted to humans through the bite of the Anopheles mosquito. Tuberculosis (TB) is an infectious disease usually caused by the bacterium Mycobacterium tuberculosis. Measles is a highly contagious infection caused by the measles virus.
39. At which stage in its life cycle does the silkworm yield the fibre of commercial use?
[A] Imago
[B] Larva
[C] Egg
[D] Pupa
Show Answer
Correct Answer: D [Pupa]
Notes:
It is during the pupa or cocoon stage that the silkworm yields the fibre of commercial use. As the silkworm prepares to pupate, it spins a protective cocoon. About the size and color of a cotton ball, the cocoon is constructed from one continuous strand of silk, perhaps 1.5 km long (nearly a mile). The silk cocoon serves as protection for the pupa.
40. 2, 4-D is used as ____:
[A] Weedicide
[B] Vitamin
[C] Fertilizer
[D] Insecticide
Show Answer
Correct Answer: A [Weedicide]
Notes:
2, 4-Dichlorophenoxyacetic acid is a s a wide range selective weedicide which controls broad leaf type (DICOT) weeds in paddy fields, tea plantations, sugarcane fields, fruit orchards etc. It is one of the most widely used herbicides in the world.