Answer:
b. The yellow arrows are all completely natural processes.
Answer:
Yes, two hydrogen bonds could form between thymine and cytosine.
Explanation:
Cytosine is a pyrimidine base found in both DNA and RNA, and Thymine is a pyrimidine base found in only DNA. Electronegative Oxygen and Nitrogen atoms with free lone pairs are potential hydrogen bond acceptors. Hydrogen atoms attached to very electronegative atoms like Oxygen and Nitrogen have strong partial positive charge and are potential hydrogen bond donors.
One hydrogen bond could form between the C4 carbonyl group on thymine which is a hydrogen bond acceptor and the C4 amino group on cytosine which is a hydrogen bond donor. Also, another hydrogen bond could be formed between N3 of thymine which is a hydrogen bond donor and the N3 of cytosine that is a hydrogen bond acceptor.
It is important to note that hydrogen bond cannot be formed between them because the C2 carbonyl groups found on both bases are both hydrogen bond acceptors.
What type of answer are you looking for? DNA? Or inheritance? Genes?
Answer:
The correct answer is option B ( ligand gated channels opened by neurotransmitter molecules).
Explanation:
Input region or postsynaptic region or dendrite is the site of neuron cell which receives the impulse from the pre-synaptic neuron at the synaptic junction.
The cell membrane of the dendrite is embedded with ligand-gated channels which opens up in response to the ligand (neurotransmitters) produced by the neurotransmitter vesicle of axon or output region of neuron.
The neuromuscular junction is such a case where acetylcholine receptors present in the dendrite opens in the presence of acetylcholine.
Thus, option B ( ligand-gated channels opened by neurotransmitter molecules) is the correct option.
