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Aquarium keepers are typically advised to remove dead fish from an aquarium the moment they are discovered. Otherwise, the water may soon become cloudy due to a bacterial bloom. Which of the following best explains why a bacterial bloom should be avoided?

A The bacteria acting on the dead organism may 1 infect other fish and aquatic organisms, causing an aquarium plague.
B The cloudiness in the tank prevents the fish keepers from properly observing their pets.
C The bacteria may become airborne with the evaporation of water from the aquarium and cause diseases in the external environment.
D The sudden spike in bacterial population may result in insufficient dissolved oxygen for the other aquatic organisms, causing more aquatic life to die.

Which of the following crops are rabi crops?

AWheat, Barley, Gram
BRice, Maize, Wheat
CBeans, Jowar, Bajra
DCarrot, Maize, Barley

Match column I with column II and select the correct option from the given codes.


A(i)-(A, B), (ii)-(E), (iii)-(D), (iv)-(C), (v)-(A)
B(i)-(E), (ii)-(C), (iii)-(A, E), (iv)-(C), (v)-(D, E)
C(i)-(C, D), (ii)-(D), (iii)-(A, B), (iv)-(E), (v)-(A)
D(i)-(E), (ii)-(C), (iii)-(A, B, C), (iv)-(E), (v)-(D)

is placed on a plane mirror. A pen is adjusted vertically until its image is seen to be at the same position when viewed from the top as shown.
Given that f is the focal length of the lens, what is the distance between the pen and the optical centre of the lens?


A 0.5 f
B f
C 2 f
D 4 f

Which of the following CANNOT be found in the given crossword?


AA hard rock used for making kitchen counters
BA type of soil which has very fine particles and has very little space for air between its particles
CLightest rock used for polishing teeth by dentists
DA precious mineral used in jewellery

Refer to the given flow chart and select the option which correctly identifies P-S.

Which of the following statements is/are incorrect regarding lysosomes?
(i) Lysosomes are small vesicles which are bounded by a single membrane.
(ii) Lysosomes occur in all animal cells with the exception of red blood cells.
(iii) Lysosomes are called suicide bags because they contain hydrolytic enzymes.
(iv) The acidic conditions are maintained inside the lysosomes by pumping Na⁺ and K⁺ ions.

A(i) and (ii) only
B(ii), (iii) and (iv) only
C(iii) only
D(iv) only

Which of the following statements is incorrect regarding the plant meristems (P, Q and R) shown in the given figure?


ABoth P and Q are responsible for longitudinal growth of a plant.
BR is responsible for increase in the width of a plant.
CNucleus in cells of P and Q is small whereas that of R is large in size.
DCells of P, Q and R are compactly arranged without intercellular spaces.

The mass of a body X in air is 0.5 kg and mass of water container Y (with water in it) is 0.8 kg. When the body X is completely immersed in the water of the container Y the readings of the respective balances get changed as shown in the given figures. What is the value of P ?


A1.3
B0.85
C0.8
D0.55

The given figure shows changes in states of matter from one form to another. Identify the processes (1 - 5) involved in different steps.
Which of the following is evaporation, sublimation and condensation respectively?


A 3, 5, 2
B 2, 4, 3
C 2, 5, 1
D 3, 1, 4