The correct answer is:
Option 4: All cis-configuration
Natural rubber is primarily made of polyisoprene, which is a polymer composed of repeating units of isoprene (C₅H₈). The structure of natural rubber has all cis-configuration at the double bonds in the polymer chain. This means that the substituents (methyl groups) are on the same side of the polymer backbone, giving the polymer a flexible, coiled structure.
All cis-configuration: This refers to all of the isoprene units in natural rubber having the same configuration, where the two methyl groups (CH₃) are on the same side of the polymer backbone.
Cis-trans isomerism: While there is also trans-configuration, which has the methyl groups on opposite sides, natural rubber specifically has all cis-configuration in its polymer chain, which contributes to its flexibility and elasticity.
A sphere of radius R is cut from a larger solid sphere of radius 2R as shown in the figure. The ratio of the moment of inertia of the smaller sphere to that of the rest part of the sphere about the Y-axis is : 
A constant voltage of 50 V is maintained between the points A and B of the circuit shown in the figure. The current through the branch CD of the circuit is :
The current passing through the battery in the given circuit, is: 
Given below are two statements:
Statement I: The primary source of energy in an ecosystem is solar energy.
Statement II: The rate of production of organic matter during photosynthesis in an ecosystem is called net primary productivity (NPP).
In light of the above statements, choose the most appropriate answer from the options given below:
Polymerization is a chemical reaction in which a large number of monomer molecules combine to produce a polymer. A polymerization can yield macromolecules with a linear or branching structure. They can also take the form of a three-dimensional complicated network.
Polymerization reactions are divided into two groups, namely, Addition polymerization (chain reaction) and condensation reaction (step reaction).