The correct answer is - A) arthropods evolved before vertebrates did.
The arthropods have evolved much earlier than the vertebrates. They were on the scene millions of years before the earliest marine forms of the vertebrates. Because the arthropods were on the scene much earlier, they managed to use the newly formed suitable environment on the land. They were initially marine, but with only slight adaptations they were able to adapt to the terrestrial life.
Once the arthropods got out of the marine environment and started to take up the niches in the terrestrial environment, they experienced a real explosion in their evolution and diversification. They were the dominant land dwellers, and because of the lack of competition, as well as the higher levels of oxygen, they managed to reach pretty big sizes for their standards. Unfortunately for them, their brain capacity is limited to a very low level, so once the competition came on the scene, they were quickly pushed from the throne as the dominant terrestrial creatures.
Explanation:
it is made up of more than one simple machine...think compound sentences are multiple simple sentences together so compound machines are multiple simple machines together
The smooth, but steady, increase in muscular tension produced by increasing the number of active motor units is called a recruitment.
Muscle tension is the force produced when a muscle contracts (or when sarcomeres shorten). The two primary forms of skeletal muscle contractions, isotonic contractions and isometric contractions, are produced when a muscle contracts against a load that is not moving.
- A load is transported as the length of the muscle varies during isotonic contractions, in which the tension in the muscle remains constant (shortens). Concentric and eccentric contractions are the two varieties of isotonic contractions.
- When a muscle contracts isometrically, the angle of a skeletal joint remains the same while tension is produced in the muscle. Sarcomeres shorten and muscles tense up during isometric contractions, but the load is not moved since the force generated is insufficient to overcome the resistance provided by the load.
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The correct answer is angioplasty.
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Angioplasty is one of the treatments after heart attack including special tubing with an attached deflated balloon. The tube is threaded up to the coronary arteries. Angioplasty is usually combined with the placement of a small tube called a stent which helps to restore the flow of blood through the artery and decreases its chance of narrowing again.</span>
