It is said that the materials found in the giant cloud that formed our solar system are comparable to the ones we have in the solar system today, which are Hydrogen and Helium!
Neurotransmitters are the chemical molecules, which help in transfer of the signals from one neuron to another. Inside the neurons, the signals are transferred as electrical signals, but at junction of two neuron, which is known as synapse, the signals are transferred in chemical forms.
These neurotransmitters have a definite shape and are recognized by the receptors present in the receptor site of the succeeding neuron. The neurotransmitters from the synapse binds to the receptor site of the receiving neuron. binding of the neurotransmitter to the receptor causes excitation of the receiving neuron, which also known as postsynaptic neuron.
Hence, Like a key in a lock, the shape of the neurotransmitter must bind with the receptors of the receiving neuron.
The answer is a C. The offsprings from this generation are from a cross between parents who are heterozygous (one parent) and homozygous recessive. This means that all the offsprings of the filial 1 (one) generation will carry a recessive allele. However, those with an equivalent dominant allele will not exhibit the attached earlobe trait. This is shown by the Punnet square below;