31. Morphology of Chromosomes can be best studied at ___:
[A] Interphase
[B] Prophase
[C] Metaphase
[D] Zygotene
Show Answer
Correct Answer: C [Metaphase]
Notes:
The morphology of the chromosomes can be distinctly studied at metaphase stage of cell division because at this stage chromosomes are in highly condensed state (25 times of orginal size) and become thicker and well arranged.
32. Which of the following are warm-blooded animals?
[A] Whales
[B] Draco
[C] Alytes
[D] Whale Sharks
Show Answer
Correct Answer: A [Whales]
Notes:
Animals, such as mammals and birds, that maintain a constant body temperature regardless of the temperature of the surroundings are called warm blooded. These include birds and mammals. Whales are aquatic mammals hence, being mammal, they are warm blooded. The have a thick layer of fats called blubber underneath their skin to maintain temperature even in cold water of oceans.
33. How the rate of absorption of water through roots can be increased?
[A] Keeping the plants under the fan
[B] Keeping the plants in the dim light
[C] Keeping the plants in the shade
[D] Covering the plants with a polythene bag
Show Answer
Correct Answer: A [Keeping the plants under the fan]
Notes:
When a plant is placed under the fan, the speed of air is increased which leads to high rate of transpiration through the stomata. The increase in the rate of transpiration increases the water absorption also. As by keeping the plants under the fan, the transpiration process is boosted. Therefore, more amount of water and other minerals are absorbed by the plant roots from the soil.
34. If a healthy freshwater fish is placed in salt water, what will be the expected consequence?
[A] The fish becomes dehydrated and dies
[B] The fish becomes bloated and dies
[C] The fish suffers from fungal or bacterial disease and dies
[D] There is no observable effect on the fish provided there is sufficient food
Show Answer
Correct Answer: A [The fish becomes dehydrated and dies]
Notes:
When freshwater fish is placed in salt water, the water molecules contained in the fish’s body would pass through the cell membranes of the fish, causing the fish to lose water by osmosis. This sudden change in the molecular makeup of the fish would cause the fish to undergo severe dehydration followed by death.
35. Columba livia is the scientific name of _____:
[A] Pigeon
[B] Shark
[C] Snake
[D] Rabbit
Show Answer
Correct Answer: A [Pigeon]
Notes:
The Rock Dove (Columba livia) or Rock Pigeon, is a member of the bird family Columbidae (doves and pigeons). In common usage, this bird is often simply referred to as the “pigeon”. The species includes the domestic pigeon (including the fancy white pigeon).
36. Red rot is a disease caused to which of the following plant?
[A] Sugarcane
[B] Wheat
[C] Paddy
[D] Mustard
Show Answer
Correct Answer: A [Sugarcane]
Notes:
Red rot is one of the oldest known diseases of sugarcane that is caused by the fungus Colletotrichum falcatum (Glomerella tucumanensis). It is characterized by interrupted red and white patches within the cane along with a sour alcoholic odour when the cane is split open.
37. Lungs of a plant are
____:
[A] Roots
[B] Flowers
[C] Stems
[D] Leaves
Show Answer
Correct Answer: D [Leaves]
Notes:
Leaves are the lungs of plants. Much like the lungs of animals, leaves are the place of a plant’s respiration. It is from leaves that oxygen is emitted during the light hours of the day and carbonic acid gas diffuse in during day and released out at night through stomata.
38. Bryophytes are often called as amphibian plant because they ____:
[A] Can eat insects
[B] Do not have habitat preference
[C] Appear like frog
[D] Are found both in water and on land
Show Answer
Correct Answer: D [Are found both in water and on land]
Notes:
Bryophytes are simple low growing plants, anchored to the ground or to tree bark by tiny filamentous rhizoids. They need presence of water for fertilization. They are characteristically limited in size and prefer moist habitats although they can survive in drier environments. The bryophytes consist of about 20,000 plant species.
39. Syrinx is the voice box in ____:
[A] Birds
[B] Reptiles
[C] Mammals
[D] Amphibians
Show Answer
Correct Answer: A [Birds]
Notes:
Syrinx is the name for the vocal organ of birds. Located at the base of a bird’s trachea, it produces sounds without the vocal cords of mammals. The sound is produced by vibrations of some or all of the membrana tympaniformis (the walls of the syrinx) and the pessulus caused by air flowing through the syrinx.
40. The tusk of elephant is an enormously enlarged ____:
[A] Upper incisor
[B] Upper canine
[C] Lower canine
[D] Lower incisor
Show Answer
Correct Answer: A [Upper incisor]
Notes:
Tusks are elongated, continuously growing front teeth, usually but not always in pairs, that protrude well beyond the mouth of certain mammal species. They are most commonly canines, as with warthogs, pig, and walruses, or, in the case of elephants, elongated incisors. The tusks are actually upper incisors, not canines. They are the only incisors the elephant has. Elephants, mastodons, and mammoths all have upper incisor teeth that emerge from the skull as tusks.
