The mitochondria is the powerhouse of the cell because it produces ATP, which is energy.
If I remember correctly, there are two main types of transport—passive and active. Passive transport does not require energy or ATP, whereas active transport does.
Types of passive transport include diffusion and osmosis, both of which involve moving down a concentration gradient and thus not requiring energy.
Active transport moves up the concentration gradient and does require energy.
Perhaps someone who has taken bio within the last several years can correct anything I might have misstated here.
The correct answer is d. spinal cord.
Spinal cord is a bundle of neurons which starts from the brain and runs down the entire length of the back of the body. The spinal cord acts as a main means to transmit the messages between the brain and the body.
Sensory or efferent neurons carry the information from the perimeter of the body and pass to the central nervous system whereas the motor or efferent neurons act as a communication channel and carry the information from the nervous system to various glands and muscles.
The earth has layers and is composed of four layers. The
four layers of the earth are namely, crust, mantle, the outer core and the
inner core. The core in the layers of the earth serves as the central region.
The mantle is the earth’s solid bulk in terms of its interior. The inner and
outer core are composed minerals and are the third and fourth layer in the
earth.
Cinder cones derive their name from their steep sides, which give them a cone-like appearance. The angle of their slopes may be as steep as 35 degrees, although older, eroded cones have softer slopes. Cinder cones are small compared to other types of volcanoes. They average 100 to 400 meters in height (325 to 1,300 feet), while composite volcanoes may reach 3,500 meters (11,500 feet) and shield volcanoes can range as high as 8,500 meters (28,000 feet) -- the height of Hawaii's Mauna Loa, the world's largest, as measured from the ocean floor to its top. Most cinder cones are monogenetic, which means they erupt only once. Their eruptions tend to be relatively weak compared to those of larger volcanoes. Cinder cones often form as parasite cones along the flanks of larger volcanoes. They are formed by Strombolian eruptions, when gas forces steaming lava upwards into the air. The lava cools and falls to the earth as pebbles, which build up around the vent that ejected them, forming a cone. These parasite types of cone volcanoes usually occur in groups. Shifts in the position of the vent result in twin cinder cones. Variations in the power of eruption create nested cones. Not all cinder cones are found in groups; some are separate entities formed on basaltic lava fields.
