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When magnesium ribbon is burnt, heat and light are produced. It is an example of

(A) Chemical change

(B) Physical and irreversible change

(C) Chemical and exothermic change

A coil is connected to a 1.5 V battery. Now, the battery is replaced by 3 V. The magnetic field around the coil

A increases
B decreases
C does not change
D may increase or decrease

Which question on the given apparatus is most likely framed?


AA. Does atmospheric pressure affect transpiration?
BDoes gravity affect the direction of plant growth?
CDoes turgor pressure affect the absorption of water?
DDoes absorbed light increase the environmental temperature?

Select the correct differences between National Park and Sanctuary.


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

The given figure shows a typical animal cell with its components labelled as 'a – j'.

Identify the labelled components and select the incorrect statement regarding them.

AThe organelles 'e', 'h', 'g' and 'i' are membranebound structures which function in close coordination with one another.
B'f' organelle is responsible for the synthesis of fats inside the cells and it stores Ca²⁺ for release during muscle contraction.
C'a' and 'b' are selectively permeable membranes.
D'j' is the site for protein synthesis. It allows hereditary message from 'd' to get translated into proteins.

A student examined a particular plant cell through its various stages of growth. After making various measurements, he realised that the increase in cell size was largely due to enlargement of the central vacuole rather than an increase in the amount of cytoplasm. Why might this be an advantageous strategy for the cell?

AEnlarging the cytoplasm would make the cell less turgid.
BEnlarging the vacuole would make it unnecessary for the cell wall to stretch.
CEnlarging the vacuole would minimise any lowering of the surface area - volume ratio of the cytoplasm.
DAll of these

Select the option that correctly fills the blanks in any two of the given statements.
(i) ______ refers to the plants found in a particular area.
(ii) ______ species are those which are going to be extinct in near term future.
(iii) The lion tailed macaque is included in ______ species in red data book.
(iv) A place rich in ______ species is called hotspot.

A(i) Fauna, (ii) Endangered
B(iii) Endangered, (iv) Endemic
C(i) Flora, (iii) Vulnerable
D(ii) Rare, (iv) Endangered

Which graph shows changes that occur in a river after being polluted by sewage?

A

B

C

D

Identify I, II and III in the given flow chart and select the correct option.


A

B

C

D

The diagram shows a bubble at the bottom of a pool. Assuming that the temperature of the pool is constant throughout the water, which of the following describes the change of the pressure and the density of air in the bubble as it rises to the surface?


--------Pressure------Density
AIncrease--------Increase
BIncrease--------Decrease
CDecrease-------Increase
DDecrease-------Decrease