Misplaced Pages

#328671

117-520: The Indian Road Congress was formed as the apex body for Engineering in Highway construction in India in the year 1934 with 73 members with the main objective for development of roads and helping to provides a stage for exchanging expertise and latest research developments relating to it are shared. The association is a group of experts from various fields of Civil Engineering laying down road safety norms in India. It

234-476: A domain and kingdom of single-celled microorganisms . These microbes are prokaryotes , meaning they have no cell nucleus or any other membrane-bound organelles in their cells. Archaea were initially classified as bacteria , but this classification is outdated. Archaeal cells have unique properties separating them from the other two domains of life, Bacteria and Eukaryota . The Archaea are further divided into multiple recognized phyla . Classification

351-496: A consequential change plastic pollution has made on the ocean and even the coasts. In January 2022 a group of scientists defined a planetary boundary for "novel entities" (pollution, including plastic pollution) and found it has already been exceeded. According to co-author Patricia Villarubia-Gómez from the Stockholm Resilience Centre, "There has been a 50-fold increase in the production of chemicals since 1950. This

468-476: A cooperative association called endosymbiosis . The engulfed bacteria and the host cell then underwent coevolution, with the bacteria evolving into either mitochondria or hydrogenosomes . Another engulfment of cyanobacterial -like organisms led to the formation of chloroplasts in algae and plants. The history of life was that of the unicellular eukaryotes, prokaryotes and archaea until about 610 million years ago when multicellular organisms began to appear in

585-439: A diameter smaller than human hair. If not ingested, this microdebris floats instead of being absorbed into the marine environment. Thompson predicts there may be 300,000 plastic items per square kilometre of sea surface and 100,000 plastic particles per square kilometre of seabed . International Pellet Watch collected samples of polythene pellets from 30 beaches in 17 countries which were analysed for organic micro-pollutants. It

702-510: A form of life or organic structures that interact with living organisms. They are considered by some to be a life form, because they carry genetic material, reproduce by creating multiple copies of themselves through self-assembly, and evolve through natural selection . However they lack key characteristics such as a cellular structure generally considered necessary to count as life. Because they possess some but not all such qualities, viruses have been described as replicators and as "organisms at

819-668: A fundamental level, marine life affects the nature of the planet, and in part, shape and protect shorelines, and some marine organisms (e.g. corals ) even help create new land via accumulated reef -building. Marine life can be roughly grouped into autotrophs and heterotrophs according to their roles within the food web : the former include photosynthetic and the much rarer chemosynthetic organisms ( chemoautotrophs ) that can convert inorganic molecules into organic compounds using energy from sunlight or exothermic oxidation , such as cyanobacteria, iron-oxidizing bacteria , algae ( seaweeds and various microalgae ) and seagrass ;

936-438: A hierarchy of nested groups—similar to a family tree. However, modern research has suggested that, due to horizontal gene transfer , this "tree of life" may be more complicated than a simple branching tree since some genes have spread independently between distantly related species. Past species have also left records of their evolutionary history. Fossils, along with the comparative anatomy of present-day organisms, constitute

1053-474: A mere 20%, most discarded plastics end up incinerated or in landfills, where they emit methane as they decompose . The international community is divided on how to address the plastic issue. Proposals range from national pledges to mandatory production controls, with the latter being supported by entities like the European Union . However, the recycling solution is under scrutiny due to low success rates. As

1170-438: A plastic beverage holder will take 400 years, a disposable nappy will take 450 years, and fishing line will take 600 years to degrade. It was estimated that global production of plastics is approximately 250 Mt per year. Their abundance has been found to transport persistent organic pollutants , also known as POPs. These pollutants have been linked to an increased distribution of algae associated with red tides . In 2019,

1287-473: A result, manufacturers choose to use plastic over other materials. However, the chemical structure of most plastics renders them resistant to many natural processes of degradation and as a result they are slow to degrade. Together, these two factors allow large volumes of plastic to enter the environment as mismanaged waste which persists in the ecosystem and travels throughout food webs . Plastic pollution can afflict land , waterways and oceans . It

SECTION 10

#1732852292329

1404-433: A result, there's a growing movement towards reducing plastic production and implementing bans on single-use plastics. States like Maine and Oregon are taking legislative action with extended producer responsibility laws to ensure that manufacturers are accountable for the lifecycle environmental impact of their products. Plastic pollution on land poses a threat to the plants and animals – including humans who are based on

1521-560: A set of studies summarized by Forbes (2019). The distribution of plastic debris is highly variable as a result of certain factors such as wind and ocean currents, coastline geography, urban areas, and trade routes. Human population in certain areas also plays a large role in this. Plastics are more likely to be found in enclosed regions such as the Caribbean. It serves as a means of distribution of organisms to remote coasts that are not their native environments. This could potentially increase

1638-627: A significant impact on ecosystems, an increase of this magnitude could have dramatic consequences. The trade in plastic waste has been identified as "a main culprit" of marine litter. Countries importing the waste plastics often lack the capacity to process all the material. As a result, the United Nations has imposed a ban on waste plastic trade unless it meets certain criteria. There are three major forms of plastic that contribute to plastic pollution: micro -, macro-, and mega-plastics. Mega- and micro plastics have accumulated in highest densities in

1755-596: Is a unique feature in the Solar System . Earth's hydrosphere consists chiefly of the oceans but technically includes all water surfaces in the world, including inland seas, lakes, rivers, and underground waters down to a depth of 2,000 metres (6,600 ft). The deepest underwater location is Challenger Deep of the Mariana Trench in the Pacific Ocean , having a depth of 10,900 metres (6.8 mi). Conventionally,

1872-551: Is categorized as either primary or secondary. Primary plastics are in their original form when collected. Examples of these would be bottle caps, cigarette butts, and microbeads. Secondary plastics, on the other hand, account for smaller plastics that have resulted from the degradation of primary plastics. Microdebris are plastic pieces between 2 mm and 5 mm in size. Plastic debris that starts off as meso- or macrodebris can become microdebris through degradation and collisions that break it down into smaller pieces. Microdebris

1989-529: Is difficult because the majority have not been isolated in the laboratory and have only been detected by analysis of their nucleic acids in samples from their environment. Archaea and bacteria are generally similar in size and shape, although a few archaea have very strange shapes, such as the flat and square-shaped cells of Haloquadratum walsbyi . Despite this morphological similarity to bacteria, archaea possess genes and several metabolic pathways that are more closely related to those of eukaryotes, notably

2106-447: Is diverse and still poorly understood, such as for the role of viruses in marine ecosystems. Most marine viruses are bacteriophages , which are harmless to plants and animals, but are essential to the regulation of saltwater and freshwater ecosystems. They infect and destroy bacteria in aquatic microbial communities, and are the most important mechanism of recycling carbon in the marine environment. The organic molecules released from

2223-452: Is estimated that 1.1 to 8.8   million tonnes of plastic waste enters the ocean from coastal communities each year. It is estimated that there is a stock of 86   million tons of plastic marine debris in the worldwide ocean as of the end of 2013, with an assumption that 1.4% of global plastics produced from 1950 to 2013 has entered the ocean and has accumulated there. Global plastic production has surged from 1.5   million tons in

2340-530: Is found elsewhere in the Solar System. Europa , one of the moons orbiting Jupiter , is slightly smaller than the Earth's Moon . There is a strong possibility a large saltwater ocean exists beneath its ice surface. It has been estimated the outer crust of solid ice is about 10–30 km (6–19 mi) thick and the liquid ocean underneath is about 100 km (60 mi) deep. This would make Europa's ocean over twice

2457-402: Is generated in sectors including agriculture (e.g. irrigation pipes, greenhouse covers, fencing, pellets, mulch; construction (e.g. pipes, paints, flooring and roofing, insulants and sealants); transport (e.g. abraded tyres, road surfaces and road markings); electronic and electric equipment (e-waste); and pharmaceuticals and healthcare. The total amounts of plastic waste generated by these sectors

SECTION 20

#1732852292329

2574-469: Is more commonly referred to as nurdles . Nurdles are recycled to make new plastic items, but they easily end up released into the environment during production because of their small size. They often end up in ocean waters through rivers and streams. Microdebris that come from cleaning and cosmetic products are also referred to as scrubbers. Because microdebris and scrubbers are so small in size, filter-feeding organisms often consume them. Nurdles enter

2691-439: Is no life without water. It has been described as the universal solvent for its ability to dissolve many substances, and as the solvent of life . Water is the only common substance to exist as a solid , liquid, and gas under conditions normal to life on Earth. The Nobel Prize winner Albert Szent-Györgyi referred to water as the mater und matrix : the mother and womb of life. The abundance of surface water on Earth

2808-456: Is produced each year; 51% in Asia, where China is the world's largest producer. From the 1950s up to 2018, an estimated 6.3   billion tonnes of plastic has been produced worldwide, of which an estimated 9% has been recycled and another 12% has been incinerated . This large amount of plastic waste enters the environment and causes problems throughout the ecosystem; for example, studies suggest that

2925-421: Is projected to triple again by 2050". There are at least 350,000 artificial chemicals in the world. They have mostly "negative effects on planetary health ". Plastic alone contain more than 10,000 chemicals and create large problems. The researchers are calling for limit on chemical production and shift to circular economy , meaning to products that can be reused and recycled. The problem of ocean plastic debris

3042-519: Is studied scientifically in both marine biology and in biological oceanography . By volume, oceans provide about 90% of the living space on Earth , and served as the cradle of life and vital biotic sanctuaries throughout Earth's geological history . The earliest known life forms evolved as anaerobic prokaryotes ( archaea and bacteria ) in the Archean oceans around the deep sea hydrothermal vents , before photoautotrophs appeared and allowed

3159-399: Is that the complex biochemistry that makes up life came from simpler chemical reactions. The beginning of life may have included self-replicating molecules such as RNA and the assembly of simple cells. In 2016 scientists reported a set of 355 genes from the last universal common ancestor (LUCA) of all life , including microorganisms, living on Earth . Current species are a stage in

3276-695: Is transported to the ocean each year. Marine life Marine life , sea life or ocean life is the collective ecological communities that encompass all aquatic animals , plants , algae , fungi , protists , single-celled microorganisms and associated viruses living in the saline water of marine habitats , either the sea water of marginal seas and oceans , or the brackish water of coastal wetlands , lagoons , estuaries and inland seas . As of 2023 , more than 242,000 marine species have been documented, and perhaps two million marine species are yet to be documented. An average of 2,332 new species per year are being described. Marine life

3393-537: Is ubiquitous. It is estimated that 1.5–4% of global plastics production ends up in the oceans every year, mainly as a result of poor waste management infrastructure and practices combined with irresponsible attitudes to the use and disposal of plastics. The weathering of plastic debris causes its fragmentation into particles that even small marine invertebrates may ingest hence contaminating the food chain. Their small size renders them untraceable to their source and extremely difficult to remove from open ocean environments. In

3510-484: Is uncertain. Several studies have attempted to quantify plastic leakage into the environment at both national and global levels which have highlight the difficulty of determining the sources and amounts of all plastic leakage. One global study has estimated that between 60 and 99   million tonnes of mismanaged plastic waste were produced in 2015. Borrelle et al. 2020 has estimated that 19–23   million tonnes of plastic waste entered aquatic ecosystems in 2016. while

3627-524: The COVID-19 pandemic due to increased demand for protective equipment and packaging materials. Higher amounts of plastic ended up in the ocean, especially plastic from medical waste and masks. Several news reports point to a plastic industry trying to take advantage of the health concerns and desire for disposable masks and packaging to increase production of single use plastic. There are differing estimates of how much plastic waste has been produced in

Indian Roads Congress - Misplaced Pages Continue

3744-714: The Eoarchean era after a geological crust started to solidify following the earlier molten Hadean Eon. Microbial mat fossils have been found in 3.48 billion-year-old sandstone in Western Australia . Other early physical evidence of a biogenic substance is graphite in 3.7 billion-year-old metasedimentary rocks discovered in Western Greenland as well as "remains of biotic life " found in 4.1 billion-year-old rocks in Western Australia. According to one of

3861-524: The Mariana Trench , the deepest spot in the Earth's oceans. Microorganisms live inside rocks 580 m (1,900 ft) below the sea floor under 2,590 m (8,500 ft) of ocean off the coast of the northwestern United States, as well as 2,400 m (7,900 ft; 1.5 mi) beneath the seabed off Japan. The greatest known temperature at which microbial life can exist is 122 °C (252 °F) ( Methanopyrus kandleri ). In 2014, scientists confirmed

3978-655: The Neoproterozoic , and which culminated in a large evolutionary radiation event of mostly sessile macrofaunae known as the Avalon Explosion . This was followed in the early Phanerozoic by a more prominent radiation event known as the Cambrian Explosion , where actively moving eumetazoan became prevalent. These marine life also expanded into fresh waters , where fungi and green algae that were washed ashore onto riparian areas started to take hold later during

4095-583: The Niger ) and eight in Asia (the Ganges , Indus , Yellow , Yangtze , Hai He , Pearl , Mekong and Amur ) "transport 88–95% of the global plastics load into the sea.". The Caribbean Islands are the biggest plastic polluters per capita in the world. Trinidad and Tobago produces 1.5 kilograms of waste per capita per day, is the biggest plastic polluter per capita in the world. At least 0.19 kg per person per day of Trinidad and Tobago's plastic debris end up in

4212-566: The Ordivician before rapidly expanding inland during the Silurian and Devonian , paving the way for terrestrial ecosystems to develop. Today, marine species range in size from the microscopic phytoplankton , which can be as small as 0.02– micrometres ; to huge cetaceans like the blue whale , which can reach 33 m (108 ft) in length. Marine microorganisms have been variously estimated as constituting about 70% or about 90% of

4329-795: The enzymes involved in transcription and translation . Other aspects of archaeal biochemistry are unique, such as their reliance on ether lipids in their cell membranes , such as archaeols . Archaea use more energy sources than eukaryotes: these range from organic compounds , such as sugars, to ammonia , metal ions or even hydrogen gas . Salt-tolerant archaea (the Haloarchaea ) use sunlight as an energy source, and other species of archaea fix carbon ; however, unlike plants and cyanobacteria , no known species of archaea does both. Archaea reproduce asexually by binary fission , fragmentation , or budding ; unlike bacteria and eukaryotes, no known species forms spores . Archaea are particularly numerous in

4446-748: The marine biomass . A microorganism , or microbe, is a microscopic organism too small to be recognised with the naked eye. It can be single-celled or multicellular . Microorganisms are diverse and include all bacteria and archaea , most protozoa such as algae , fungi , and certain microscopic animals such as rotifers . Many macroscopic animals and plants have microscopic juvenile stages . Some microbiologists also classify viruses (and viroids ) as microorganisms, but others consider these as nonliving. Microorganisms are crucial to nutrient recycling in ecosystems as they act as decomposers . Some microorganisms are pathogenic , causing disease and even death in plants and animals. As inhabitants of

4563-415: The microbial mats to expand into shallow water marine environments . The Great Oxygenation Event of the early Proterozoic significantly altered the marine chemistry , which likely caused a widespread anaerobe extinction event but also led to the evolution of eukaryotes through symbiogenesis between surviving anaerobes and aerobes . Complex life eventually arose out of marine eukaryotes during

4680-496: The scientific classification changed after the discovery in the 1990s that prokaryotes consist of two very different groups of organisms that evolved from an ancient common ancestor. These evolutionary domains are called Bacteria and Archaea . The ancestors of modern bacteria were unicellular microorganisms that were the first forms of life to appear on Earth, about 4 billion years ago. For about 3 billion years, most organisms were microscopic, and bacteria and archaea were

4797-474: The thermophilic archaea, particularly the orders Sulfolobales and Thermoproteales . Viruses are an important natural means of transferring genes between different species, which increases genetic diversity and drives evolution. It is thought that viruses played a central role in the early evolution, before the diversification of bacteria, archaea and eukaryotes, at the time of the last universal common ancestor of life on Earth. Viruses are still one of

Indian Roads Congress - Misplaced Pages Continue

4914-414: The 16.9% of the mismanaged plastic waste in the oceans, according to a study published by Science in 2015. All the European Union countries combined would rank eighteenth on the list. In 2020, a study revised the potential 2016 U.S. contribution to mismanaged plastic; It estimated that U.S.-generated plastic might place the U.S. behind Indonesia and India in oceanic pollution, or it might place

5031-860: The 1950s to 335   million tons in 2016, resulting in environmental concerns. A significant issue arises from the inefficient treatment of 79% of plastic products, leading to their release into landfills or natural environments. Some researchers suggest that by 2050 there could be more plastic than fish in the oceans by weight. Living organisms, particularly marine animals , can be harmed either by mechanical effects such as entanglement in plastic objects, problems related to ingestion of plastic waste, or through exposure to chemicals within plastics that interfere with their physiology . Degraded plastic waste can directly affect humans through direct consumption (i.e. in tap water), indirect consumption (by eating plants and animals), and disruption of various hormonal mechanisms. As of 2019, 368   million tonnes of plastic

5148-448: The 1950s. The plastic industry's greenhouse gas emissions are substantial, having emitted 1.8 billion metric tons in 2019, with the potential to exceed 2.5 billion metric tons by 2050 if no changes are made. The United States is on track to see its plastic emissions increase from 317 million metric tons in 2021 to 401 million by 2025, primarily due to production and disposal methods. With global recycling rates for plastic packaging at

5265-572: The Australian coast. They found the highly variable microplastic counts to be proportionate to plastic on the surface and the angle of the seafloor slope. By averaging the microplastic mass per cm , they estimated that Earth's seafloor contains about 14   million tons of microplastic – about double the amount they estimated based on data from earlier studies – despite calling both estimates "conservative" as coastal areas are known to contain much more microplastic. These estimates are about one to two times

5382-614: The DNA or RNA of viruses and are a useful means of investigating how they arise. Viruses are now recognised as ancient and as having origins that pre-date the divergence of life into the three domains . But the origins of viruses in the evolutionary history of life are unclear: some may have evolved from plasmids —pieces of DNA that can move between cells—while others may have evolved from bacteria. In evolution, viruses are an important means of horizontal gene transfer , which increases genetic diversity . Opinions differ on whether viruses are

5499-541: The Northern Hemisphere, concentrated around urban centers and water fronts. Plastic can be found off the coast of some islands because of currents carrying the debris. Both mega- and macro-plastics are found in packaging, footwear, and other domestic items that have been washed off of ships or discarded in landfills . Fishing-related items are more likely to be found around remote islands. These may also be referred to as micro-, meso-, and macro debris. Plastic debris

5616-465: The Pew Charitable Trusts and SYSTEMIQ (2020) have estimated that 9–14   million tonnes of plastic waste ended up in the oceans the same year. Despite global efforts to reduce the generation of plastic waste, losses to the environment are predicted to increase. Modelling indicates that, without major interventions, between 23 and 37   million tonnes per year of plastic waste could enter

5733-569: The Philippines, Thailand and Vietnam. The table below list the top 20 plastic waste polluting countries in 2010 according to a study published by Science , Jambeck et al (2015). All the European Union countries combined would rank eighteenth on the list. In a study published by Environmental Science & Technology , Schmidt et al (2017) calculated that ten rivers: two in Africa (the Nile and

5850-440: The U.S. behind Indonesia, India, Thailand, China, Brazil, Philippines, Egypt, Japan, Russia, and Vietnam. In 2022, it was estimated all OECD countries (North America, Chile, Colombia, Europe, Israel, Japan, S. Korea) may contribute 5% of oceanic plastic pollution, with the rest of the world polluting 95%. Since 2016 China ceased importing plastics for recycling and since 2019 international treaties signed by 187 countries restricted

5967-607: The United States is higher than in any other country, with the average American producing 130.09 kilograms of plastic waste per year. Other high-income countries, such as those of the EU-28 (annual per capita generation 58.56 kg), also have a high per capita plastic waste generation rate. Some high-income countries, such as Japan (annual per capital generation 38.44 kg), produce far less plastic waste per capita. The United States National Academy of Sciences estimated in 2022 that

SECTION 50

#1732852292329

6084-527: The accumulation of oxygen in the atmosphere from photosynthesis. About 500 million years ago, plants and fungi started colonising the land. Evidence for the appearance of the first land plants occurs in the Ordovician , around 450  million years ago , in the form of fossil spores. Land plants began to diversify in the Late Silurian , from around 430  million years ago . The colonisation of

6201-546: The amount of plastic thought – per Jambeck et al., 2015 – to currently enter the oceans annually. Plastic debris is categorized as macrodebris when it is larger than 20 mm. These include items such as plastic grocery bags. Macrodebris are often found in ocean waters, and can have a serious impact on the native organisms. Fishing nets have been prime pollutants. Even after they have been abandoned, they continue to trap marine organisms and other plastic debris. Eventually, these abandoned nets become too difficult to remove from

6318-694: The archaeal/eukaryotic lineage. Bacteria were also involved in the second great evolutionary divergence, that of the archaea and eukaryotes. Here, eukaryotes resulted from the entering of ancient bacteria into endosymbiotic associations with the ancestors of eukaryotic cells, which were themselves possibly related to the Archaea . This involved the engulfment by proto-eukaryotic cells of alphaproteobacterial symbionts to form either mitochondria or hydrogenosomes , which are still found in all known Eukarya. Later on, some eukaryotes that already contained mitochondria also engulfed cyanobacterial-like organisms. This led to

6435-402: The average virus is about one one-hundredth that of the average bacterium . Most viruses cannot be seen with an optical microscope so electron microscopes are used instead. Viruses are found wherever there is life and have probably existed since living cells first evolved. The origin of viruses is unclear because they do not form fossils, so molecular techniques have been used to compare

6552-483: The bodies of 90% of seabirds contain plastic debris. In some areas there have been significant efforts to reduce the prominence of free range plastic pollution, through reducing plastic consumption, litter cleanup, and promoting plastic recycling . As of 2020, the global mass of produced plastic exceeds the biomass of all land and marine animals combined. A May 2019 amendment to the Basel Convention regulates

6669-515: The bus stop should be decided after leaving enough area for pedestrians. Roads in India . Plastic waste Plastic pollution is the accumulation of plastic objects and particles (e.g. plastic bottles, bags and microbeads ) in the Earth's environment that adversely affects humans, wildlife and their habitat. Plastics that act as pollutants are categorized by size into micro-, meso-, or macro debris. Plastics are inexpensive and durable, making them very adaptable for different uses; as

6786-430: The carbon budget. The OECD estimated the emissions from plastic as 1.8 GtCO2 (3.7% of total emissions) in 2019 which will rise to 4.3 GtCO2 (4.5% of total emissions) in 2060, without measures to reduce them. In a 2024 Bloomberg article, the ever-increasing consumption of plastics was highlighted as a critical environmental issue. Global use is projected to reach 1.1 billion metric tons by 2050, up from just 2 million in

6903-482: The consumption of virgin plastic by one third. Pepsico responded that they want to decrease "virgin plastic in our beverage business by 35% by 2025" and also expanding reuse and refill practices what should prevent 67   billion single use bottles by 2025. A study from 2024, using the Break Free From Plastic dataset, found that of the aforementioned 50% of the waste that was identifiable by brand, 11%

7020-594: The dead bacterial cells stimulate fresh bacterial and algal growth. Viral activity may also contribute to the biological pump , the process whereby carbon is sequestered in the deep ocean. A stream of airborne microorganisms circles the planet above weather systems but below commercial air lanes. Some peripatetic microorganisms are swept up from terrestrial dust storms, but most originate from marine microorganisms in sea spray . In 2018, scientists reported that hundreds of millions of viruses and tens of millions of bacteria are deposited daily on every square meter around

7137-450: The deep portions of Earth's crust . Bacteria also live in symbiotic and parasitic relationships with plants and animals. Once regarded as plants constituting the class Schizomycetes , bacteria are now classified as prokaryotes . Unlike cells of animals and other eukaryotes , bacterial cells do not contain a nucleus and rarely harbour membrane-bound organelles . Although the term bacteria traditionally included all prokaryotes,

SECTION 60

#1732852292329

7254-410: The dominant forms of life. Although bacterial fossils exist, such as stromatolites , their lack of distinctive morphology prevents them from being used to examine the history of bacterial evolution, or to date the time of origin of a particular bacterial species. However, gene sequences can be used to reconstruct the bacterial phylogeny , and these studies indicate that bacteria diverged first from

7371-450: The earth's remaining carbon budget . By 2100 it will emit 260   billion tonnes, more than half of the carbon budget. Those are emission from production, transportation, incineration, but there are also releases of methane and effects on phytoplankton . The emissions of methane from plastic decomposition and impact on phytoplankton, were still not known well when the report was released. According to one estimate, plastic floating in

7488-399: The edge of life". Bacteriophages , often just called phages , are viruses that parasite bacteria and archaea. Marine phages parasite marine bacteria and archaea, such as cyanobacteria . They are a common and diverse group of viruses and are the most abundant biological entity in marine environments, because their hosts, bacteria, are typically the numerically dominant cellular life in

7605-506: The emergence of these first multicellular organisms, a remarkable amount of biological diversity appeared over a span of about 10 million years, in an event called the Cambrian explosion . Here, the majority of types of modern animals appeared in the fossil record, as well as unique lineages that subsequently became extinct. Various triggers for the Cambrian explosion have been proposed, including

7722-473: The entrance of any property . To prevent parking of vehicles on the footpath, Bollards should be placed with a clear width of minimum 1.2m towards the left. To avoid buses pulling over towards left side,stops for buses should be placed adjacent to their linear path of travel and also its inappropriate positioning results in passengers waiting extending to the street during the wait time. To decrease travel time for commuters, bus bays should be avoided. Position for

7839-463: The evolution of these large animals, smaller organisms similar to the types that evolved early in this process continue to be highly successful and dominate the Earth, with the majority of both biomass and species being prokaryotes. Estimates on the number of Earth's current species range from 10 million to 14 million, of which about 1.2 million have been documented and over 86 percent have not yet been described. Microorganisms make up about 70% of

7956-546: The existence of microorganisms living 800 m (2,600 ft) below the ice of Antarctica . According to one researcher, "You can find microbes everywhere — they're extremely adaptable to conditions, and survive wherever they are." Viruses are small infectious agents that do not have their own metabolism and can replicate only inside the living cells of other organisms . Viruses can infect all types of life forms , from animals and plants to microorganisms , including bacteria and archaea . The linear size of

8073-405: The export of plastics for recycling. A 2019 study calculated the mismanaged plastic waste, in millions of metric tonnes (Mt) per year: Around 275   million tonnes of plastic waste is generated each year around the world; between 4.8 million and 12.7   million tonnes is dumped into the sea. About 60% of the plastic waste in the ocean comes from the top five countries: China, Indonesia,

8190-472: The exportation/importation of plastic waste, largely intended to prevent the shipping of plastic waste from developed countries to developing countries . Nearly all countries have joined this agreement. On 2 March 2022, in Nairobi, 175 countries pledged to create a legally binding agreement by the end of the year 2024 with a goal to end plastic pollution. The amount of plastic waste produced increased during

8307-468: The few areas where they differ helps shed light on when the common ancestor of these species existed. Prokaryotes inhabited the Earth from approximately 3–4 billion years ago. No obvious changes in morphology or cellular organisation occurred in these organisms over the next few billion years. The eukaryotic cells emerged between 1.6 and 2.7 billion years ago. The next major change in cell structure came when bacteria were engulfed by eukaryotic cells, in

8424-490: The footpath safely . Indian Road Congress (IRC) laid down the following guidelines as per international best practices which are specified by the Institute for Transportation and Development Policy (ITDP). Based on the adjacent land use any footpath width can vary but mandatory requirement of 1.8 metres of minimum clear width is necessary in residential areas as space required for two wheelchairs to cross and for commercial areas

8541-481: The formation of chloroplasts in algae and plants. There are also some algae that originated from even later endosymbiotic events. Here, eukaryotes engulfed a eukaryotic algae that developed into a "second-generation" plastid. This is known as secondary endosymbiosis . The largest known bacterium, the marine Thiomargarita namibiensis , can be visible to the naked eye and sometimes attains 0.75 mm (750 μm). The archaea (Greek for ancient ) constitute

8658-430: The group Break Free From Plastic organized over 70,000 volunteers in 51 countries to collect and identify plastic waste. These volunteers collected over "59,000 plastic bags, 53,000 sachets and 29,000 plastic bottles," as reported by The Guardian . Nearly half of the items were identifiable by consumer brands. The most common brands were Coca-Cola , Nestlé , and Pepsico . According to the global campaign coordinator for

8775-480: The land by plants was soon followed by arthropods and other animals. Insects were particularly successful and even today make up the majority of animal species. Amphibians first appeared around 364 million years ago, followed by early amniotes and birds around 155 million years ago (both from " reptile "-like lineages), mammals around 129 million years ago, homininae around 10 million years ago and modern humans around 250,000 years ago. However, despite

8892-524: The land. Estimates of the amount of plastic concentration on land are between four and twenty three times that of the ocean. The amount of plastic poised on the land is greater and more concentrated than that in the water. Mismanaged plastic waste ranges from 60 percent in East Asia and Pacific to one percent in North America. It is estimated that between 1 million and 1.7 million tonnes of mismanaged plastic

9009-527: The largest environment on Earth, microbial marine systems drive changes in every global system. Microbes are responsible for virtually all the photosynthesis that occurs in the ocean, as well as the cycling of carbon , nitrogen , phosphorus , other nutrients and trace elements. Viruses [REDACTED] Bacteria [REDACTED] Archaea     [REDACTED] Protists [REDACTED] Microfungi   [REDACTED] Microanimals   [REDACTED] Microscopic life undersea

9126-442: The largest reservoirs of unexplored genetic diversity on Earth. Bacteria constitute a large domain of prokaryotic microorganisms . Typically a few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods and spirals. Bacteria were among the first life forms to appear on Earth , and are present in most of its habitats . Bacteria inhabit soil, water, acidic hot springs , radioactive waste , and

9243-477: The last century. By one estimate, one billion tons of plastic waste have been discarded since the 1950s. Others estimate a cumulative human production of 8.3   billion tons of plastic, of which 6.3   billion tons is waste, with only 9% getting recycled. It is estimated that this waste is made up of 81% polymer resin , 13% polymer fibres and 32% polymer additives . In 2018 more than 343   million tonnes of plastic waste were generated, 90% of which

9360-453: The latter include all that are not considered vertebrates . Generally, marine vertebrates are much more nektonic and metabolically demanding of oxygen and nutrients, often suffering distress or even mass dyings (a.k.a. " fish kills ") during anoxic events , while marine invertebrates are a lot more hypoxia -tolerant and exhibit a wide range of morphological and physiological modifications to survive in poorly oxygenated waters . There

9477-427: The latter include all the rest that must feed on other organisms to acquire nutrients and energy, which include animals, fungi, protists and non-photosynthetic microorganisms. Marine animals are further informally divided into marine vertebrates and marine invertebrates , both of which are polyphyletic groupings with the former including all saltwater fish , marine mammals , marine reptiles and seabirds , and

9594-633: The marine biomass. It is estimated viruses kill 20% of this biomass each day and that there are 15 times as many viruses in the oceans as there are bacteria and archaea. Viruses are the main agents responsible for the rapid destruction of harmful algal blooms , which often kill other marine life. The number of viruses in the oceans decreases further offshore and deeper into the water, where there are fewer host organisms. There are also archaeal viruses which replicate within archaea : these are double-stranded DNA viruses with unusual and sometimes unique shapes. These viruses have been studied in most detail in

9711-529: The marine environment, plastic pollution causes "Entanglement, toxicological effects via ingestion of plastics, suffocation, starvation, dispersal, and rafting of organisms, provision of new habitats, and introduction of invasive species are significant ecological effects with growing threats to biodiversity and trophic relationships. Degradation (changes in the ecosystem state) and modifications of marine systems are associated with loss of ecosystem services and values. Consequently, this emerging contaminant affects

9828-420: The method for their polymerization . Depending on their chemical composition, plastics and resins have varying properties related to contaminant absorption and adsorption . Polymer degradation takes much longer as a result of saline environments and the cooling effect of the sea. These factors contribute to the persistence of plastic debris in certain environments. Recent studies have shown that plastics in

9945-492: The morphological, or anatomical, record. By comparing the anatomies of both modern and extinct species, paleontologists can infer the lineages of those species. However, this approach is most successful for organisms that had hard body parts, such as shells, bones or teeth. Further, as prokaryotes such as bacteria and archaea share a limited set of common morphologies, their fossils do not provide information on their ancestry. More recently, evidence for common descent has come from

10062-404: The movement of pedestrians. An ideal footpath helps in integration of multiple elements with a unified structure. For pedestrian movements smoothly,it is recommended for footpaths to be continuous till the entrance of property . They should have standard height and for warning visually impaired people about possible movement of vehicles there should be a display of warning tiles on either part of

10179-450: The ocean by means of spills during transportation or from land based sources. The Ocean Conservancy reported that China, Indonesia, Philippines, Thailand, and Vietnam dump more plastic in the sea than all other countries combined. It is estimated that 10% of the plastics in the ocean are nurdles, making them one of the most common types of plastic pollution, along with plastic bags and food containers. These micro-plastics can accumulate in

10296-402: The ocean can emit annually 76 Mt methane equal to 2,129 Mt CO2e, based on the 100 years global warming potential of methane. But these numbers are very preliminary. From one side, it can be an overestimate as it is based on the emissions of LDPE in powder form, the most emission intensive type of plastic in this case and in tropical water where intense radiation increases decomposition. But from

10413-430: The ocean decompose faster than was once thought, due to exposure to sun, rain, and other environmental conditions, resulting in the release of toxic chemicals such as bisphenol A . However, due to the increased volume of plastics in the ocean, decomposition has slowed down. The Ocean Conservancy has predicted the decomposition rates of several plastic products. It is estimated that a foam plastic cup will take 50 years,

10530-476: The ocean, or for example Saint Lucia which generates more than four times the amount of plastic waste per capita as China and is responsible for 1.2 times more improperly disposed plastic waste per capita than China. Of the top thirty global polluters per capita, ten are from the Caribbean region. These are Trinidad and Tobago, Antigua and Barbuda , Saint Kitts and Nevis , Guyana , Barbados , Saint Lucia , Bahamas , Grenada , Anguilla and Aruba , according to

10647-547: The oceanic temperature distribution can cause significant weather shifts, such as the El Niño-Southern Oscillation . Altogether the ocean occupies 71 percent of the world surface, averaging nearly 3.7 kilometres (2.3 mi) in depth. By volume, the ocean provides about 90 percent of the living space on the planet. The science fiction writer Arthur C. Clarke has pointed out it would be more appropriate to refer to planet Earth as planet Ocean. However, water

10764-725: The oceans and allow for the accumulation of Persistent Bio-accumulating Toxins such as bisphenol   A , polystyrene , DDT, and PCB's which are hydrophobic in nature and can cause adverse health affects. A 2004 study by Richard Thompson from the University of Plymouth , UK, found a great amount of microdebris on beaches and in waters in Europe, the Americas, Australia, Africa, and Antarctica. Thompson and his associates found that plastic pellets from both domestic and industrial sources were being broken down into much smaller plastic pieces, some having

10881-411: The oceans by 2040 and between 155 and 265   million tonnes per year could be discharged into the environment by 2060. Under a business as usual scenario, such increases would likely be attributable to a continuing rise in production of plastic products, driven by consumer demand, accompanied by insufficient improvements in waste management. As the plastic waste released into the environment already has

10998-814: The oceans every year out of which the 83,1% is from the following 20 countries: China is the most mismanaged plastic waste polluter leaving in the sea the 27.7% of the world total, second Indonesia with the 10.1%, third Philippines with 5.9%, fourth Vietnam with 5.8%, fifth Sri Lanka 5.0%, sixth Thailand with 3.2%, seventh Egypt with 3.0%, eighth Malaysia with 2.9%, ninth Nigeria with 2.7%, tenth Bangladesh with 2.5%, eleventh South Africa with 2.0%, twelfth India with 1.9%, thirteenth Algeria with 1.6%, fourteenth Turkey with 1.5%, fifteenth Pakistan with 1.5%, sixteenth Brazil with 1.5%, seventeenth Myanmar with 1.4%, eighteenth Morocco with 1.0%, nineteenth North Korea with 1.0%, twentieth United States with 0.9%. The rest of world's countries combined wind up

11115-493: The oceans in the Ediacaran period. The evolution of multicellularity occurred in multiple independent events, in organisms as diverse as sponges , brown algae , cyanobacteria , slime moulds and myxobacteria . In 2016 scientists reported that, about 800 million years ago, a minor genetic change in a single molecule called GK-PID may have allowed organisms to go from a single cell organism to one of many cells. Soon after

11232-415: The other side it can be an underestimate, as it is not including the decomposition of plastic on land which is probably more emission intensive, the effects on phytoplankton which can be significant, the emissions from submerged plastic. Therefore, the authors prefer to not include them in the official estimate, but to write them in the full report, as a base for further discussion noting the high importance of

11349-403: The planet is divided into five separate oceans, but these oceans all connect into a single world ocean . The mass of this world ocean is 1.35 × 10   metric tons or about 1/4400 of Earth's total mass. The world ocean covers an area of 3.618 × 10  km with a mean depth of 3682 m , resulting in an estimated volume of 1.332 × 10  km . If all of Earth's crustal surface was at

11466-443: The planet. Microscopic organisms live throughout the biosphere . The mass of prokaryote microorganisms — which includes bacteria and archaea, but not the nucleated eukaryote microorganisms — may be as much as 0.8 trillion tons of carbon (of the total biosphere mass , estimated at between 1 and 4 trillion tons). Single-celled barophilic marine microbes have been found at a depth of 10,900 m (35,800 ft) in

11583-435: The problem. The United Nations Environment Programme used 2 different studies to estimate the impact of plastic on climate: according to the first, by the year 2040 the annual emissions from plastic will reach 2.1 GtCO2 and will consume 19% of the 1.5 degrees carbon budget , while the second estimated the emissions in the year 2015 as 1.7 GtCO2 and predicted that by the year 2050 they will reach 6.5 GtCO2, consuming 15% of

11700-569: The process of evolution, with their diversity the product of a long series of speciation and extinction events. The common descent of organisms was first deduced from four simple facts about organisms: First, they have geographic distributions that cannot be explained by local adaptation. Second, the diversity of life is not a set of unique organisms, but organisms that share morphological similarities . Third, vestigial traits with no clear purpose resemble functional ancestral traits and finally, that organisms can be classified using these similarities into

11817-503: The project Emma Priestland in 2020, the only way to solve the problem is stopping production of single use plastic and using reusable products instead. Coca-Cola answered that "more than 20% of our portfolio comes in refillable or fountain packaging", they are decreasing the amount of plastic in secondary packaging. Nestlé responded that 87% of their packaging and 66% of their plastic packaging can be reused or recycled and by 2025 they want to make it 100%. By that year they want to reduce

11934-424: The researchers, "If life arose relatively quickly on Earth … then it could be common in the universe ." All organisms on Earth are descended from a common ancestor or ancestral gene pool . Highly energetic chemistry is thought to have produced a self-replicating molecule around 4 billion years ago, and half a billion years later the last common ancestor of all life existed. The current scientific consensus

12051-424: The salt in the ocean comes from the weathering and erosion of rocks on land. Some salts are released from volcanic activity or extracted from cool igneous rocks . The oceans are also a reservoir of dissolved atmospheric gases, which are essential for the survival of many aquatic life forms. Sea water has an important influence on the world's climate, with the oceans acting as a large heat reservoir . Shifts in

12168-428: The same elevation as a smooth sphere, the depth of the resulting world ocean would be about 2.7 kilometres (1.7 mi). About 97.5% of the water on Earth is saline ; the remaining 2.5% is fresh water . Most fresh water – about 69% – is present as ice in ice caps and glaciers . The average salinity of Earth's oceans is about 35 grams (1.2 oz) of salt per kilogram of seawater (3.5% salt). Most of

12285-416: The same should be minimum 2.5m. After providing for required space for drainage and prevention of formation of puddles, flat walking surfaces should be provided in footpaths. To assist visual impaired people it is recommended to lay guide tiles along the length of the path. Well planned footpaths provides space for walking and has provision of additional space for roadside vendors and bus stops not affecting

12402-541: The sea. Generally there are about 1 million to 10 million viruses in each mL of seawater, or about ten times more double-stranded DNA viruses than there are cellular organisms, although estimates of viral abundance in seawater can vary over a wide range. Tailed bacteriophages appear to dominate marine ecosystems in number and diversity of organisms. Bacteriophages belonging to the families Corticoviridae , Inoviridae and Microviridae are also known to infect diverse marine bacteria. Microorganisms make up about 70% of

12519-577: The socio-economic aspects through negative impacts on tourism, fishery, shipping, and human health". In 2019 a new report "Plastic and Climate" was published. According to the report, in 2019, production and incineration of plastic will contribute greenhouse gases in the equivalent of 850   million tonnes of carbon dioxide (CO 2 ) to the atmosphere. In current trend, annual emissions from these sources will grow to 1.34   billion tonnes by 2030. By 2050 plastic could emit 56   billion tonnes of greenhouse gas emissions, as much as 14 percent of

12636-461: The study of biochemical similarities between organisms. For example, all living cells use the same basic set of nucleotides and amino acids . The development of molecular genetics has revealed the record of evolution left in organisms' genomes: dating when species diverged through the molecular clock produced by mutations. For example, these DNA sequence comparisons have revealed that humans and chimpanzees share 98% of their genomes and analysing

12753-483: The total marine biomass . Marine primary producers , mainly cyanobacteria and chloroplastic algae , produce oxygen and sequester carbon via photosynthesis , which generate enormous biomass and significantly influence the atmospheric chemistry . Migratory species, such as oceanodromous and anadromous fish , also create biomass and biological energy transfer between different regions of Earth, with many serving as keystone species of various ecosystems. At

12870-481: The variability and dispersal of organisms in specific areas that are less biologically diverse. Plastics can also be used as vectors for chemical contaminants such as persistent organic pollutants and heavy metals . Plastic pollution has also greatly negatively affected our environment. "The pollution is significant and widespread, with plastic debris found on even the most remote coastal areas and in every marine habitat". This information tells us about how much of

12987-524: The volume of the Earth's ocean. There has been speculation Europa's ocean could support life , and could be capable of supporting multicellular microorganisms if hydrothermal vents are active on the ocean floor. Enceladus , a small icy moon of Saturn, also has what appears to be an underground ocean which actively vents warm water from the moon's surface. The Earth is about 4.54 billion years old. The earliest undisputed evidence of life on Earth dates from at least 3.5 billion years ago, during

13104-462: The water because they become too heavy, having grown in weight up to 6 tonnes. 9.2 billion tonnes of plastic are estimated to have been made between 1950 and 2017. More than half this plastic has been produced since 2004. Of all the plastic discarded so far, 14% has been incinerated and less than 10% has been recycled. Plastics themselves contribute to approximately 10% of discarded waste. Many kinds of plastics exist depending on their precursors and

13221-541: The worldwide entry of plastic into the ocean was 8   million metric tons of plastic per year. A 2021 study by The Ocean Cleanup estimated that rivers convey between 0.8 and 2.7   million metric tons of plastic into the ocean, and ranked these river's countries. The top ten were, from the most to the least: Philippines, India, Malaysia, China, Indonesia, Myanmar, Brazil, Vietnam, Bangladesh, and Thailand. Top 12 mismanaged plastic waste polluters In 2018 approximately 513   million tonnes of plastics wind up in

13338-483: Was attributable to Coca-Cola, 5% to Pepsico, 3% to Nestle, 3% to Danone , and 2% to Altria , totaling 24% of the total branded count. 56 companies accounted for over 50% of the branded items. According to The Plastic Waste Makers index, 55% of plastic waste worldwide is created by 20 companies. The United States is the world leader in generating plastic waste, producing an annual 42   million metric tons of plastic waste. Per capita generation of plastic waste in

13455-674: Was composed of post-consumer plastic waste (industrial, agricultural, commercial and municipal plastic waste). The rest was pre-consumer waste from resin production and manufacturing of plastic products (e.g. materials rejected due to unsuitable colour, hardness, or processing characteristics). A large proportion of post-consumer plastic waste consists of plastic packaging . In the United States plastic packaging has been estimated to make up 5% of MSW. This packaging includes plastic bottles, pots, tubs and trays, plastic films shopping bags, rubbish bags, bubble wrap, and plastic or stretch wrap and plastic foams e.g. expanded polystyrene (EPS). Plastic waste

13572-449: Was found that pellets found on beaches in the US, Vietnam and southern Africa contained compounds from pesticides suggesting a high use of pesticides in the areas. In 2020 scientists created what may be the first scientific estimate of how much microplastic currently resides in Earth's seafloor, after investigating six areas of around 3 km (1.9 mi) depth about 300 km (190 mi) off

13689-768: Was set up after the recommendation of Jayakar Committee also known as Indian Road Development Committee. Currently the association has 13,500 members from various fields of engineering consisting of varied ranks in Border Roads Organisation,state and Central governments, engineering services in Army,Institutes in Road Research, engineering colleges, local bodies and private enterprises. In 2013 Indian Roads Congress had released codes for using plastic wastes for laying roads across country. Design in any road should adhere to certain basic principles for helping pedestrians navigate

#328671