The answer is oil.
The United States' fossil shortage of oil makes the country dependent on outside sources. Mineral oil such as crude oil or commonly known as petroleum came from the ancient fossilized organic materials. This resource is limited. The US is now facing a shortage in oil and becoming dependent to some countries such as middle-east countries.
In general, the function of the excretory system is, removal of nitrogen waste products from the bloodstream and transport out of the body through urine. It maintains the balance of fluids and electrolytes, control of red blood cells, regulation of blood pressure and also the formation of red bone marrow.
In humans, the excretory system is responsible for removing waste from the body. Metabolic waste is being removed from the blood and an appropriate amount of water nutrients and water and salt are being retained.
In frogs, the excretory system consists of a pair of ureters, kidney pairs, cloaca, and urinary bladder. Frogs take in liquid waste from kidney which removes wastes and then the extra water becomes urine which then it is collected in the urinary bladder through ureters.
The urinary bladder is present in ventral to return then both open into the cloaca.
Answer and Explanation:
The steps of the sliding filament theory are:
Muscle activation: breakdown of energy (ATP) by myosin.
Before contraction begins, myosin is only associated with a molecule of energy (ATP), which myosin breaks down into its component molecules (ADP + P) causing myosin to change shape.
Muscle contraction: cross-bridge formation
The shape change allows myosin to bind an adjacent actin, creating a cross-bridge.
Recharging: power (pulling) stroke
The cross-bridge formation causes myosin to release ADP+P, change shape, and to pull (slide) actin closer to the center of the myosin molecule.
Relaxaction: cross-bridge detachment
The completion of the pulling stroke further changes the shape of myosin. This allows myosin and ATP to bind, which causes myosin to release actin, destroying the cross-bridge. The cycle is now ready to begin again.
The repeated cycling through these steps generates force (i.e., step 2: cross-bridge formation) and changes in muscle length (i.e., step 3: power stroke), which are necessary to muscle contraction.
Answer:
A) Hummingbirds drinking nectar from a plant.
Step-by-step explanation:
Here are some examples of natural selection: In a habitat there are red bugs and green bugs. The birds prefer the taste of the red bugs, so soon there are many green bugs and few red bugs. The green bugs reproduce and make more green bugs and eventually there are no more red bugs.
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