A Muscle Contraction Is Triggered When an Action Potential Travels Along the Nerves to the Muscles. Muscle contraction begins when the nervous system generates a signal. The signal, an impulse called an action potential, travels through a type of nerve cell called a motor neuron.
Answer:
B) a sequence of three nucleotides
Explanation:
A codon is the sequence of three nucleotides that decide that which particular amino acid would be incorporated in the polypeptide chain. Each codon code for a particular amino acid and responsible for the primary structure of proteins.
During translation the transfer RNA have the anticodon on its one side and amino acid bound to it on its other side. It adds the amino acids to growing polypeptide chain by binding to particular codon on messenger RNA.
Example; AUG is the starting codon for every protein and code for methionine in eukaryotes and anticodon for it is UAC.
Answer:
C. Allantois
Explanation:
The allantois is one of the four extraembryonic membranes that develop as an out-pocket of the yolk sac. The main function of allantois is to store the toxic waste, the nitrogenous waste and protects the embryo from the harmful effects of these waste products.
The allantois is a vascularized structure and its blood vessels become the blood vessels of the umbilical cord. Later, it becomes part of the urinary bladder.