Answer:
The correct answer will be option-C
Explanation:
The rhythm of the heartbeat is controlled by the pacemaker of the heart called the sino-atrial node.
The SA node generates action potentials which trigger the contraction and relaxation of the atrium and ventricles. The membrane potential generation initiates by the depolarization of the cell membrane when the L type of Ca⁺² ions opens up and calcium ions enter the cell.
This depolarizes the cell until the potential threshold is reached which lies between the -40 and -30 mV.
Thus, Option-C is the correct answer.
Answer:
Due to presence of these structures in ancient as well as modern organisms.
Explanation:
Homologous and vestigial structures are the evidences that show evolutionary relationships between organisms because these structure were also present in the ancient ancestor of that organism. These homologous and vestigial structures shows the relationship between the ancient and the modern organisms. Some structure has a purpose and function in the body of ancient organisms but with the passage of time those structure are useless and have no function in the body but these structure shows connection between modern and ancient organisms.
Answer:A.) True
Explanation:
E.Coli would be a good model organism to study how the cell membrane controls movement of substances in and out of cells because it a eubacteria .Eubacteria characteristics include the ability to allow the movement of molecules across its membrane once a proton gradient is established , The membrane also has permeability enhancing properties that allow for the easy movement of substances.
Answer:
influenza struck (sick) patient
new patient comes into contact with sick patient.
sick patient sneezes
new patient inhales through nose
new patient is infected
Explanation:
