Rainwater harvesting is the accumulating and storing, of rainwater. It has been used to provide drinking water, water for livestock, water for irrigation or to refill aquifers in a process called groundwater recharge. Rainwater collected from the roofs of houses, tents and local institutions, can make an important contribution to the availability of drinking water. Water collected from the ground, sometimes from areas which are especially prepared for this purpose, is called Stormwater harvesting. In some cases, rainwater may be the only available, or economical, water source. Rainwater harvesting systems can be simple to construct from inexpensive local materials, and are potentially successful in most habitable locations.
Wednesday, February 16, 2011
BIODIVERSITY
Biodiversity is the degree of variation of life forms within a given ecosystem, biome, or an entire planet. Biodiversity is a measure of the health of ecosystems. Greater biodiversity implies greater health. Biodiversity is in part a function of climate. In terrestrial habitats, tropical regions are typically rich whereas polar regions support fewer species.
Rapid environmental changes typically cause extinctions. One estimate is that less than 1% of the species that have existed on Earth are extint.
Since life began on Earth, five major mass extinctions and several minor events have led to large and sudden drops in biodiversity. The Phanerozoic eon (the last 540 million years) marked a rapid growth in biodiversity via the Cambrian explosion—a period during which nearly every phylum of multicellular organisms first appeared. The next 400 million years included repeated, massive biodiversity losses classified as mass extinction events. In the Carboniferous, rainforest collapse led to a great loss of plant and animal life. The Permian–Triassic extinction event, 251 million years ago, was the worst; vertebrate recovery took 30 million years. The most recent, the Cretaceous–Tertiary extinction event, occurred 65 million years ago, and has attracted more attention than all others because it killed the nonavian dinosaurs.
The period since the emergence of humans has displayed an ongoing biodiversity reduction and an accompanying loss of genetic diversity. Named the Holocene extinction, the reduction is caused primarily by human impacts, particularly habitat destruction. Biodiversity's impact on human health is a major international issue.
The United Nations designated 2010 as the International Year of Biodiversity.
Rapid environmental changes typically cause extinctions. One estimate is that less than 1% of the species that have existed on Earth are extint.
Since life began on Earth, five major mass extinctions and several minor events have led to large and sudden drops in biodiversity. The Phanerozoic eon (the last 540 million years) marked a rapid growth in biodiversity via the Cambrian explosion—a period during which nearly every phylum of multicellular organisms first appeared. The next 400 million years included repeated, massive biodiversity losses classified as mass extinction events. In the Carboniferous, rainforest collapse led to a great loss of plant and animal life. The Permian–Triassic extinction event, 251 million years ago, was the worst; vertebrate recovery took 30 million years. The most recent, the Cretaceous–Tertiary extinction event, occurred 65 million years ago, and has attracted more attention than all others because it killed the nonavian dinosaurs.
The period since the emergence of humans has displayed an ongoing biodiversity reduction and an accompanying loss of genetic diversity. Named the Holocene extinction, the reduction is caused primarily by human impacts, particularly habitat destruction. Biodiversity's impact on human health is a major international issue.
The United Nations designated 2010 as the International Year of Biodiversity.
Tuesday, February 15, 2011
BIOLOGY
1. Which famous scientist introduced the idea of natural selection?
2. A person who studies biology is known as a?
3. Botany is the study of?
4. Can frogs live in salt water?
5. True or false? The common cold is caused by a virus.
6. Animals which eat both plants and other animals are known as what?
7. Bacterial infections in humans can be treated with what?
8. A single piece of coiled DNA is known as a?
9. A group of dog offspring is known as a?
10. The area of biology devoted to the study of fungi is known as?
11. What is the name of the process used by plants to convert sunlight into food?
12. The death of every member of a particular species is known as what?
13. The process of pasteurization is named after which famous French microbiologist?
14. True or false? A salamander is a warm blooded animal?
15. A change of the DNA in an organism that results in a new trait is known as a?
ANSWERS
1. Charles Darwin 2. Biologist 3. Plants
4. No 5. True 6. Omnivores
7. Antibiotics 8. Chromosome 9. Litter
10. Mycology 11. Photosynthesis 12. Extinction
13. Louis Pasteur 14. False 15. Mutation
1. Charles Darwin 2. Biologist 3. Plants
4. No 5. True 6. Omnivores
7. Antibiotics 8. Chromosome 9. Litter
10. Mycology 11. Photosynthesis 12. Extinction
13. Louis Pasteur 14. False 15. Mutation
THE INTERNATIONAL YEAR OF FORESTS
The year 2011 was declared the International Year of Forests by the United Nations to raise awareness and strengthen the sustainable forest management, conservation and sustainable development of all types of forests for the benefit of current and future generations.
THE INTERNATIONAL YEAR OF CHEMISTRY
The International Year of Chemistry 2011 (IYC 2011) will commemorate the achievements of chemistry, and its contributions to humankind. This recognition for chemistry was made official by the United Nations in December 2008. Events for the year are being coordinated by IUPAC, the International Union of Pure and Applied Chemistry, and by UNESCO, the United Nations Educational, Scientific, and Cultural Organization.
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