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Showing posts from September, 2022

Fungi and Lichens

 Fungi were once thought of as plants but are now classified as a separate kingdom. This kingdom includes not only the familiar mushrooms, puffballs, stinkhorns and moulds, but also yeasts, smuts, rusts and lichens. Most fungi are multicellular, consisting of a mass of thread like hyphae that together form a mycelium. However, the simpler fungi are microscopic, single-called organisms. Typically, fungi reproduce by means of spores.  Most fungi feed on dead of decaying matter, or on living organisms. A few fungi feed on dead or decaying matter, or on living organisms. A few fungi obtain their food plants or algae, with which they have a symbiotic partnership between algae and fungi. Of the six types of lichens the three most common are crustose, foliose and fruticose. Some lichens are a combination of types. Lichens reproduce by means of spores or soredia ( powdery vegetative fragments)

Global Positioning System

 The Global Positioning System(GPS) is a network of 24 navigating satellites orbiting the Earth that people can use to  pinpoint their position. The satellites orbit at a height of 20,000 kilometers. A GPS receivers picks up signals from any of these satellites that are above the horizon. It uses information in each signal to work out how far away it is from the satellite. It can calculate it's position on the Earth's surface when it has information from at least three satellites.  A basic GPS receivers shows the latitude and longitude of its position on its screen. More advanced receivers, especially those designed for use in vehicles, show their position on a digital map. These receivers often show extra information, such as the vehicle's speed and the length of the journey. Some receivers warm drivers if they exceed the speed limit for a road and even tell drivers which traffic lane to use at the next junction. Directions are shown on the screen and also spoken by a sy...

LAKES AND GROUNDWATER FACTS

 Natural lake occur where a large quantity of water collects in a hollow in impermeable rock, or is prevented from draining away by a harrier, such as moraine or solidified lava. lakes are often relatively short-lived landscape features, as they tend to become silted up by sediment from the streams and rivers that feed them. Some of the more long-lasting lakes are found in deep rift valleys formed by vertical movements of the Earth's crust - for example, Lake Baikal in Russia, the world's largest freshwater lake and the Dead Sea in the Middle East, one of the world's saltiest lakes. Where waters is able to drain away, in sinks into the ground until it reaches a layer of impermeable rock, then accumulates in the permeable rock, then accumulates in the permeable rock above it, this water - saturated permeable rock is called an aquifer. The saturated zone varies in depth according to seasonal and climatic changes. In wet conditions, the water stored underground builds up, whil...

OCEANS AND SEAS FACTS

 Oceans and seas cover the about 70 percent of the earth's surface and account for about 97 percent of its total water. These Oceans and seas play a crucial role in regulating temperature variation and determining climate. Their waters absorbs heat from the Sun, especially in tropical regions, and the surface currents distribute it around the Earth, warming overlying air masses and neighboring land in winter and cooling them in summer. The Oceans are never still. Differences in temperature and salinity drive deep current systems , while surface currents are generated by winds blowing over the oceans. All currents and deflected- to the right in the Northern Hemisphere, to the left in the Southern hemisphere- as a result of the Earths rotation. This deflective factor is known as the Coriolis force. A current that begins on the surface is immediately deflected. This current in turn generates a current in the layer of water beneath, which is also deflected. As the movement is transmitt...