The P wave of the electrocardiogram is considered as a signal from the DEPOLARIZATION of the atria in the heart. This depolarization drives the contraction of the atrial musculature.
An electrocardiogram (ECG) is a device that records the electrical activity of the heart. This record can then be used to diagnose different heart conditions.
The P waves occur when the sinoatrial node generates an action potential which is capable of depolarizing the atria.
This depolarization is then followed by atrial contraction and an increase of the pressure in the atria.
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A vascular plant is a plant that is characterized by the presence of conducting tissue.
Answer:
Primary producers use energy from the sun to produce
Explanation:
Primary producers use energy from the sun to produce their own food in the form of glucose, and then primary producers are eaten by primary consumers who are in turn eaten by secondary consumers, and so on, so that energy flows from one trophic level, or level of the food chain, to the next.
Answer: The correct answer for the first question is- B) Mechanical.
Adaptation can be described as a process of change in an organism over time that facilitates its survival in the changing environmental conditions. It results due to mutation or genetic change in the individual that gives a benefit to the organism. It exhibits change in structure ( like succulent plants in desert), function, or behavior.
Mechanical is not a type of adaptation as it deals with movement of objects.
The correct answer for second question is- C) Variations.
Variation among organisms in a population results from change in the genetic material or their genetic sequences. Change at the genetic level is thus reflected in the phenotypes ( like different color of feathers in birds).
Thus, difference is in the feather color reflects variations.
He is incorrect because a catalyst is a substance that speeds up a chemical reaction so if there is no reaction to begin with a catalyst will not due anything.
