<span>They do not possess any skeleton at al</span>
A clade is a group of species that includes an ancestral species and all of its descendents
The answer is; A
When an impulse from the motor neuron reached the neuromuscular junction, the voltage-dependent calcium channels are activated and the neurotransmitter released from the presynaptic cleft. When the neurotransmitter binds to their receptors on the sarcolemma, the muscle fibers become depolarised; the calcium is released from their vesicles. The Ca2+ ions are important in the power stroke because they bind to troponin. Upon binding calcium, troponin moves tropomyosin away from the myosin-binding sites on actin. Powered by the energy from ATP molecule, the myosin is able to bind on the actin and slides over the actin filament.
Cell phones emit radiofrequency radiation (radio waves), a form of non-ionizing radiation, from their antennas. Parts of the body nearest to the antenna can absorb this energy. ... Over time, the number of cell phone calls per day, the length of each call, and the amount of time people use cell phones have increased.
The answer is; Carbon dioxide levels in the Earth’s atmosphere have been steadily increasing.
Data has shown a direct relationship between the increase in the levels of carbon dioxide in the atmosphere and rising global temperatures. The rise in the global temperatures can be observed through the melting of Arctic and Antarctic glaciers, the rise in ocean levels, and extreme weather events.
