Answer:
The correct answer will be option A.
Explanation:
The electrical impulses are generated in the sino-atrial node or SA node, a mass of cells which generates impulse in the upper atrium.
This electrical impulse transmits from the sino-atrial node to the atrio-ventricular node in the lower portion of the upper atrium through the internodal pathway- the pathway composed of atrial cells.
Once the impulse reaches the AV node, it is transferred to the ventricular portion of the heart through Bundle of His presence in the ventricular septum. This bundle of his divides into left and right ventricles through bundle branches and stimulates both the ventricles.
Thus, option-A is the correct answer.
Answer:
D) A Survey of fellow classmates
Explanation:
This is the correct answer because an informal survey involves various answers that may or may not be accurate. Informal surveys cannot be held as scientific fact and are, therefore, not reliable. A scientific journal is reliable because it most likely includes data from an experiment and/or research of a trusted scientist or group. The results of past experiments are very reliable because these are the results of hard work and thorough planning and research. A scientific discussion with colleagues is not very credible because it involves the sharing of opinionated information, but it is certainly more reliable that the varying answers of school-aged peers.
Lunar maria (plural form of the Latin word mare, which means sea) are dark surfaces that can be found all over the moon (17% of the Moon is covered in them) that have been created as a result of volcanic eruptions. These areas are made up of basalt, and given that they seemed almost waterlike, the astronomers in the distant past mistook them for seas, whence their name comes.
When it comes to craters, their origin is quite similar - volcanic eruptions created them. When lava starts erupting from a volcano, it has to get out from somewhere - and thus craters are created. If you are referring to lunar craters, however, there are many speculations as to how they were created: due to volcanic eruptions, meteoric impact, or glacier activity.
Answer: Wavelength, wave period, and wave frequency.
