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What are the characteristics of plants?

Another characteristic of plants is that they do not voluntarily move, though they may grow branches in a particular direction. Animals have to move in order to search for food, but plants remain stationary because they make their own food. While some marine plants float on water, they do not move of their own volition.\nMost plants branch. Because sunlight, water and air are necessary for photosynthesis, the branching allows the plant to absorb as much of these necessities as possible. Unlike different species of animals that have a specific shape, plants of the same species do not have a pre..

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What was the name of the first spacecraft that visited the planet Mars?

Prior to Mariner 9's orbit around Mars, Mariner 6 and 7 took atmospheric measurements during a flyby in 1969. In 1997, the Mars Global Surveyor began orbiting Mars, while Mars Pathfinder landed on the surface. The Mars Exploration Rovers Spirit and Opportunity arrived on Mars in 2002. In 2012, NASA's rover Curiosity landed on Mars to explore its Gale Crater.

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How long do stars last?

All stars follow the same pattern of formation from a gas cloud, to burning fuel in the main sequence, and then expansion to a red giant. After the red giant phase, smaller stars cool and become white or black dwarf stars. Stars of larger masses may collapse during a one-million-year period, ending with a supernova explosion that lasts fractions of a second. The result is a neutron star or a black hole.

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How many moons does Eris have?

As a dwarf planet, Eris orbits the sun but is not the dominant gravitational force in its orbit. However, a dwarf planet can have one or more moons, as seen with both Eris and Pluto. The existence of moons on far off planets such as Eris is important for measuring the size of the orbited planet. Dysnomia derives its name from the same Greek myths as Eris. In Greek mythology, Dysnomia is the daughter of Eris.

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How do CD4 cells protect you from infections?

CD4 cells are a type of white blood cell made in the spleen, thymus gland and lymph nodes. CD4 is a molecular protein present on the surface of immune cells such as T-cells, monocytes, macrophages and dendritic cells. CD4 cells fight off bacteria and viruses before they weaken the body and cause illness. CD4 cells reduce viral and bacterial load, says About.com.\nCD4 count is a measure of the number of CD4 cells per cubic millimeter in a sample of human blood. CD4 count ascertains the strength of a person's immune system. HIV binds to CD4 cells, altering their genetic coding, which limits..

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What smaller hip muscle is commonly used as an injection site?

Intramuscular injections are shots of medicine given into the muscle. There are several types of injections that must be given this way, including those for medicines that need to take effect quickly and for medicines that cannot be taken orally, injected into a blood vessel or absorbed through the skin. The common sites for intramuscular injections include the thigh, top of the upper arm, hip and buttocks, notes Scott & White Healthcare.\nA needle used for an intramuscular injection needs to be long enough to penetrate into the deep end of the muscle. Needles are measured by their length and ..

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What is the difference between erosion and weathering?

There are two kinds of weathering, mechanical and chemical. Mechanical weathering breaks rocks into small pieces and fragments. Chemical weathering changes mineral structures inside of rocks. The pieces of rock fall off, but the rock itself stays put during both types of weathering processes. Erosion, which is also called mass wasting, happens when the weathered pieces of rock roll down-slope, along with another agent, such as in the case of a mud slide or moving ice floe.

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What is a list of all carnivores in the food chain?

Lions and tigers are great cats. Lions are found mostly in Africa, while the larger tigers are found in Asia. Lions form family groups called prides, where the females hunt cooperatively. Tigers are mostly solitary. Other great cats include the cheetah, the jaguar, the snow leopard and the mountain lion. The cheetah is one of the fastest animals on earth and is unusual for a great cat in that it hunts during the day. It also does not roar; instead, it purrs.\nSpotted hyenas are also found in Africa. Like lions, they hunt in female-dominated clans. The females not only lead the clans, but they ..

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What disease destroys the cells of the anterior gray horn?

The polio virus causes poliomyelitis. The virus is transmitted through direct contact with infected individuals or their feces, as stated by the Merck Manual. Many people have no symptoms; others experience a minor infection. In those cases where the virus invades the central nervous system, the affected person can experience muscle pain, muscle spasms, urinary retention, trouble breathing and paralysis. The best way to prevent polio is to vaccinate infants and young children.

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What are the similarities between the tundra and the taiga biomes?

Taiga is a belt of boreal forests in the northern hemisphere, spreading across Canada and Russia. Tundra lies to the north of taiga and to the south of the Arctic Circle. Tundra and taiga biomes are similar, mostly in that they lie close to the North Pole. However, average temperatures, biological diversity and soil fertility all drop as one moves from taiga to tundra.Both taiga and tundra have short, cool summers and a limited growing season. Both exhibit drastic season changes and are transformed in springtime, when the snow melts and new grasses and flowering plants sprout. In tundra the sh..

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