NEET Practice Questions (MCQs) with Answers & Solutions

The NCERT text explicitly states that genetic modification has '(ii) reduced reliance on chemical pesticides (pest-resistant crops).'

The NCERT material explains, 'These two RNA’s being complementary to each other formed a double stranded (dsRNA) that initiated RNAi...'

The NCERT states, 'Agrobacterium tumifaciens, a pathogen of several dicot plants is able to deliver a piece of DNA known as ‘T-DNA’ to transform normal plant cells into a tumor...'

The explanation indicates that the 'silencing of the specific mRNA of the nematode' leads to its inability to survive. The transgenic plant therefore got itself protected from the parasite.

According to the NCERT text, 'The specific heat capacity is the property of the substance which determines the change in the temperature of the substance (undergoing no phase change) when a given quantity of heat is absorbed (or given off) by it. It is defined as the amount of heat per unit mass absorbed or given off by the substance to change its temperature by one unit.' Mathematically, it is expressed as $s = \frac{1}{m} \frac{\Delta Q}{\Delta T}$.

The NCERT text states, 'The SI unit of molar specific heat capacity is J mol$^{-1}$ K$^{-1}$'. J kg$^{-1}$ K$^{-1}$ is the unit for specific heat capacity (per unit mass).

From the NCERT text: 'For a mole of a solid, the total energy is $U = 3 k_B T \times N_A = 3 RT$. Now, at constant pressure, $\Delta Q = \Delta U + P \Delta V \cong \Delta U$, since for a solid $\Delta V$ is negligible. Therefore, $C = \frac{\Delta Q}{\Delta T} = \frac{\Delta U}{\Delta T} = 3R$'. This value generally agrees with experimental values at ordinary temperatures.

The NCERT text states, 'The specific heat capacity is the property of the substance... It depends on the nature of the substance and its temperature.' It does not depend on the amount of substance.

The NCERT text explains: 'However, in connection with specific heat capacity of gases, additional conditions may be needed to define C. In this case, heat transfer can be achieved by keeping either pressure or volume constant. If the gas is held under constant pressure during the heat transfer, then it is called the molar specific heat capacity at constant pressure and is denoted by $C_p$. On the other hand, if the volume of the gas is held constant, it is denoted by $C_v$.'

Specific heat capacity is defined as the amount of heat per unit mass required to change its temperature by one unit. Therefore, 4186 J kg$^{-1}$ K$^{-1}$ means that 4186 Joules of heat energy are needed to raise the temperature of 1 kg of water by 1 Kelvin (or 1 degree Celsius).