The Earth's crust comprises about 95% igneous and metamorphic rocks, 4% shale, 0.75% sandstone, and 0.25% limestone. Oxygen, silicon, aluminum, and iron account for 88.1% of the mass of the Earth's crust, while another 90 elements make up the remaining 11.9%.
Answer: it's because they need to provide a lot of energy.
Explanation: fat cells have many mitochondria because they store a lot of energy. Muscle cells have many mitochondria, which allows them to respond quickly to the need for doing work.
The right option is a. flea is
more active in a dry environment
Kinesis is an activity or physical
movement of a living cell or an organism in response to a stimulus such as
light intensity or humidity. Under kinesis, the response to the stimulus activated
by an organism is non-directional.