Answer:
A Muscle Contraction Is Triggered When an Action Potential Travels Along the Nerves to the Muscles. Muscle contraction begins when the nervous system generates a signal. The signal, an impulse called an action potential, travels through a type of nerve cell called a motor neuron.
Answer: Elephants, humans, and bison are all k-selected species. On the other hand, r-selected species often inhabit unstable environments and are completely density independent. These species often have short life expectancies, produce as many offspring as they can, and invest very low amounts of parental care. You can see r- and K-selected strategies clearly by looking at different organisms within a phylogenetic group, such as the mammals. For example, elephants are highly K-selected, whereas mice are much more r-selected. Among the fishes, most, like the salmon, are r-selected. brainliest????
Explanation:
In the movement of sperm tail plays an important role due to which sperm is able to move.
Sperm move to the uterine tube through uterine contractions and the energy of their own flagella.
Motility of sperm is also depend upon various metabolic pathways and the mechanism of regulation.
<h3>What is causes sperm to move?</h3>
The structure of sperm contains tail which have large numbers of protons channels which are known as Hv1 channels that respond to changes in pH and concentration of zinc outside the cell.
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Sexual reproduction because sexual reproduction leads to genetic variation.
Answer: Active transport
Explanation: Active transport is a process of transferring materials with the expenditure of energy