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What are the predators of the black-tailed prairie dogs?

Because of the abundance of predators, prairie dogs have listening posts near the exits of their elaborate underground warrens. They have a special chirp-like call that signals danger is near. One prairie dog makes the initial warning and others take it up. When the danger is past and it is safe to come out, an individual sounds the all-clear, others echo it, and soon the entire town is yipping and dancing.\nBlack-tailed prairie dogs live in communities called towns that typically cover a square mile and contain a few hundred individuals. However, the largest known town was spread over 25,000 ..

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What is the function of nonsense codon?

The genetic machinery uses short sequences of nucleotides to indicate the start and stop locations for transcription. Between these start and stop signals lie the active genes that code for building functional proteins. Occasionally, a single-point mutation alters a sequence in these instructions and transforms a short stretch of nucleotides into a stop signal, such as TAG or TAA, that prematurely instructs the messenger RNA to halt production of a peptide chain and release it in its unfinished state.\nAn analogy for what nonsense codons do would be the words "the end" appearing in the middle ..

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How is the endocrine system involved in reproduction?

In humans and other mammals, testosterone, estrogen and progesterone are major sex hormones that control the release of gametes and, in females, also the preparation of the uterus for supporting young. After birth in mammals, hormones also control the release of milk for feeding young.\nThe endocrine system, as a whole, shares a role with the nervous system, handling long-term tasks for which the fast, energetic action of nerves is not needed. Hormones have no dedicated signal pathways like nerves do; instead, they travel from the glands that produce them through the blood to the sites where t..

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How does a nerve impulse travel along a neuron?

When a neuron is at rest, it is in a state of polarization. There is an excess of sodium (Na+) ions outside of the cell membrane that create a positive charge. Similarly, there is an excess of potassium (K+) ions inside the cell along with negatively charged molecules that produce a negative charge inside the cell membrane.\nWhen a neuron is stimulated, either from direct sensory input or another neuron, ion channels in the cell membrane open, and sodium ions rush in. The inside of the cell becomes positively charged, the cell depolarizes and an action potential is created that transmits the s..

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Can I use a plastic water bottle over and over?

There has been a lot of research about the possible risks of BPA a chemical compound found in plastic water bottles leeching into the water. The American Cancer Society and Cancer Research U.K. have denounced the leeching of chemicals such as BPA as myths. Canada and some countries in the European Union have banned the use of BPA in baby bottles, as children have a decreased ability to clear the chemical from their systems.

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How do tsunamis form?

Tsunamis also form as a result of undersea landslides. The formation process is similar. Displaced water seeks a stable position, and in doing so, creates a tsunami. In rare cases, tsunamis occur when meteors strike the ocean and displace a large amount of water.\nNot all earthquakes or landslides result in tsunami waves. Only those that occur with enough violence to displace a large amount of water very quickly have this devastating effect. Tsunamis are not single waves. Instead, they are a series of large waves in quick succession. These waves may not appear large on the open ocean, but as t..

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What is countercurrent heat exchange?

Without a system of countercurrent heat exchange, the blue whale would not be able to take in the amount of cold water needed to feed itself sufficiently. Also, the heat transported by the arteries to the tip of the tongue would not be employed as effectively. As it is, veins with blood cooled by the water run parallel to the arteries in the whale's tongue, and the blood is efficiently warmed before it returns to the body. The flippers of the dolphin and the blue whale employ the same countercurrent heat exchange system.\nParallel pipes running in the same direction, such as two veins or ..

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What is red salvia?

The variation of red salvia grown in gardens is usually a dwarf variation of the natural plant, altered through selective breeding. The natural plant is several times larger than the cultivated variety. In its natural environment, it grows on mountains with consistently high temperatures and humidity at elevations of between 6,600 and 9,800 feet.

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What is equilibrium?

The equilibrium equation for a chemical reaction is expressed in terms of the concentration of the reactants and products. Dynamic equilibrium occurs when the chemical reaction proceeds, but the amount of products and reactants remain constant. Chemical reactions behave similarly. They occur in both forward and backward directions, and when the both reaction rates become equal, products and reactants remain constant. This state is referred to as equilibrium.

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What is an enolate ion?

An enolate is an intermediate form of enol. The process of creation of enol in base catalyst has an intermediate stage where enolate is formed. In order to fully understand the formation of enol, the formation of enolate, or vice versa, must be taken into consideration. In aqueous solutions, ketone loses its hydrogen atom in water. The resulting carbonyl compound is known as enolate. Enolates are prepared with the help of using a base. The majority of the charge in an enolate anion is on O; however, the charge can be either on carbon atom (C) or on oxygen atom (O). In both the cases, the charg..

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