31. The point mutation results in a change in the codon, which then codes for another amino acid is called __
[A] Silent mutation
[B] Nonsense mutation
[C] Missense mutation
[D] None of these
Show Answer
Correct Answer: C [Missense mutation]
Notes:
The point mutation results in a change in the codon, which then codes for another amino acid is called Missense mutation.
32. What is required for nitrogen fixation by Rhizobium?
[A] Potassium
[B] Phosphorus
[C] Nitrate
[D] Sodium
Show Answer
Correct Answer: B [Phosphorus]
Notes:
Phosphorus is required for nitrogen fixation by Rhizobium. This is a genus of Gram-negative soil bacteria.
33. Which of the following is an enzyme that cleaves proteins?
[A] protease
[B] RNase
[C] lipase
[D] Dnase
Show Answer
Correct Answer: A [protease]
Notes:
Protease is an enzyme that cleaves proteins. These enzymes are made by animals, plants, fungi, and bacteria.
34. 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.
35. What is Blood?
[A] Muscular tissue
[B] Epithelial tissue
[C] Reproductive tissue
[D] Connective tissue
Show Answer
Correct Answer: D [Connective tissue]
Notes:
Blood is considered a connective tissue for two basic reasons:
(i) embryologically, it has the same origin (mesodermal) as do the other connective tissue types and
(ii) blood connects the body systems together bringing the needed oxygen, nutrients, hormones and other signaling molecules, and removing the wastes.
36. In male sharks, Claspers are found attached to
____:
[A] Anal fin
[B] Ventral fin
[C] Pectoral fin
[D] Pelvic fin
Show Answer
Correct Answer: D [Pelvic fin]
Notes:
Claspers are organs found in male elasmobranchs. Each male has two claspers. They are located along the inner side of the shark or ray’s pelvic fin and are used in reproduction. During mating, the male deposits his sperm into the female’s cloaca (the opening that serves as the entrance to the uterus, intestine and urinary tract) via grooves that lie in the upper side of the claspers.
37. Which one of the following is an insectivorous plant?
[A] Nostoc
[B] Utricularia
[C] Bryophyta
[D] Sequoia Gigantia
Show Answer
Correct Answer: B [Utricularia]
Notes:
Utricularia (also called bladderworts) is a genus of insectivorous plants. They occur in fresh water and wet soil as terrestrial or aquatic species. All Utri cularia are carnivorous and capture small organisms by means of bladder-like traps. Aquatic species feed on protozoa and rotifers swimming in water-saturated soil’ while terrestrial species feed on water fleas (Daphnia), nematodes and even fish fry, mosquito larvae and young tadpoles.
38. Bio-magnification implies ____:
[A] Food is magnified
[B] Living beings are magnified
[C] Light is magnified
[D] Toxic matters are magnified
Show Answer
Correct Answer: D [Toxic matters are magnified]
Notes:
Biomagnification is the sequence of processes in an ecosystem by which higher concentrations of a particular chemical such as the pesticide DDT, are reached in organisms higher up the food chain. It’s principal cause is eutrophication of stagnant water leading to the increase in BOD level. The some biomagnifcation has led to the ban on the use of DDT as a pesticide.
39. The number of heart beats on an average in an adult human is in the range of ___:
[A] 60-65
[B] 66-70
[C] 71-80
[D] 85-90
Show Answer
Correct Answer: C [71-80]
Notes:
The average heart rate for adult humans is about 70 to 75 beats per minute in a normal relaxed mode. While we tend to think of the “normal” heart beat rate as being “72 beats per minute”, in actuality the heart beat rate is not and could never be constant.
40. Which blood group individuals are universally known as recipients because they can receive blood from any group?
[A] Group O
[B] Group A
[C] Group B
[D] Group AB
Show Answer
Correct Answer: D [Group AB]
Notes:
Blood group AB individuals are universally known as recipients because they can receive blood from any group, this is due to the presence of both A and B antigens on the surface of their RBC’s and an absence of antibodies against either A or B antigen in the plasma. However, they can only donate blood to individuals of the same AB blood group.
