Answer:
The answer is A.
Explanation:
The permeability of the pacemaker cell's membrane is the factor that controls the density of the materials inside the cell which also includes sodium and that controls the neurons and muscles. So if we were able to artificially alter the pacemaker cell's membrane parmeability, for the heart it would result in a quicker satisfaction of the threshold value and therefore would increase the heart rate.
I hope this answer helps.
Macronutrients can be defined as the compounds which can be found in large quantities in the human diet. Majority of the energy for the functioning of the body is derived from these macronutrients. These includes the fats, carbohydrates, and the proteins.
Micronutrients can be defined as the compounds which are required by the body in small quantities, but they are essential for the proper growth of the body. These includes the vitamins and minerals.
Hence, the given food and the nutrient groups can be matched as follows:
Macronutrients - Carbohydrates, proteins, fats.
Micronutrients - Zinc, calcium.
B. animals
Plants have cell walls, bacteria are unicellular and fungi have cell walls too
The correct answer is B. The Kuiper Belt is home to a dwarf planet similar to Pluto
Explanation
The Kuiper Belt is the most remote area of the solar system, it is an elliptical region, which is more or less 149.5 million kilometers from the sun. Its name refers to the fact that it is a belt, so it could be associated with the appearance of the asteroid belt that is located between Mars and Jupiter. However, in the Kuiper Belt most objects are icy rather than rocky. In this region of the solar system you can find several dwarf planets such as Pluto, these planets are classified as such because their size is enough to be considered as or asteroids, but they cannot be considered planets either because they do not meet any requirement. According to the above, the correct answer is B. The Kuiper Belt is home to a dwarf planet similar to Pluto
