January 2022

Effects of Coronavirus Disease 2019 (COVID-19) on Students in Elementary, Secondary, and Postsecondary Schools

Advice and Recommendations for the Public ( Students, Teachers and other Employees)
Your risk of infection is low if you are not in an area where COVID-19 is spreading, have not travelled from an area where COVID-19 is spreading, or have not come into contact with an infected patient. It is critical to be aware of the situation and to take the necessary precautions to protect yourself and your family.
If you live in a region where COVID-19 cases have been reported, you should be concerned about the potential of infection. Follow WHO recommendations as well as national and local health authority guidance. COVID-19 infection causes minor disease in most individuals, but it can make some people very sick, and in some cases, it can be fatal. Older people and those with pre-existing medical conditions (such as cardiovascular disease, chronic respiratory disease, or diabetes) are more likely to develop severe disease.

Photo-Phosphorylation: Cyclic and Non-cyclic and Effects of Red Drop and Enhancement

Effects of Red Drop and Enhancement
Emerson and Lewis’ demonstration of the red drop proved perplexing. Because the quantum yield only measures the light that has been absorbed, this is not attributable to a decrease in light absorption. This means that light with wavelengths longer than 680 nm is inefficient compared to light with shorter wavelengths. After modifying their fluorescence rates to give equivalent rates of photosynthesis, Emerson and his colleagues evaluated photosynthesis using red and far-red light in subsequent tests. The quantum yield obtained by combining red and far-red light was substantially higher than the sum of the yields obtained by combining red and far-red light separately. Emerson enhancement effect, or Emerson effect, is the name given to this occurrence.
These perplexing red drop and amplification effects led to the conclusion that photosynthesis involves two separate reaction centres or photochemical activities. Red light ( 680 nm) drives one event, while far-red light (> 680 nm) drives the other. When both activities are driven simultaneously or in rapid succession, optimal photosynthesis occurs. These two photochemical reactions are now referred to as Photosystem II and Photosystem I, and they work in tandem to optimise photosynthesis. Photosystem II absorbs red light with a wavelength of 680 nm well but is poorly driven by far-red light. Photosystem I, on the other hand, prefers to absorb far-red light with wavelengths larger than 680 nm.

Photosynthesis: Light Reaction, The Electron Transport, and  Water Splitting

Light Reaction
The photochemical phase is also known as the light reaction. It involves the absorption of light, the splitting of water, the release of oxygen, and the production of high-energy chemical intermediates (ATP and NADPH). The process involves a large number of complexes.
Within Photosystem I (PS I) and Photosystem II (PS II), the pigments are arranged into two distinct photochemical light-harvesting complexes (LHC). The photosystems are called according to the order in which they were discovered, not their function during the light reaction.
Except for one molecule of chlorophyll a, each photosystem contains all of the pigments. The reaction centre is formed by a single chlorophyll molecule. PS I is named after the reaction centre chlorophyll a, which has an absorption peak at 700 nm. PS II has an absorption maximum at 680 nm, hence the name PS680.

Photosynthesis: Definition, Early Findings, and Pigments

Photosynthesis is important since
1. 1. It is the principal food source.
2. It releases oxygen into the environment.
Early Findings
1. Jan Ingenhousz: Experiment with aquatic plants in light and dark – He discovered that sunlight is required for plant purification activities.
2. Julius Von Sachs: Plants produce glucose and store it as starch in their green portions.
3. T.W. Engelmann: Spilt light utilising prism into 7 colours (VIBGYOR) – Green Algae Cladophora in a suspension of aerobic bacteria – Bacteria were utilised to detect O2 evolution sites.
4. Cornelius van Niel: He experimented with purple and green bacteria and established that photosynthesis is a light-dependent process in which CO2 is reduced to carbohydrates using hydrogen from H2O. He concluded that oxygen comes from H2O, not CO2.

Factors Affecting Photosynthesis | Class 10th, 11th, and NEET

Concept of Cardinal Values: Numerous environmental elements affect metabolic processes. The magnitude of each element affects the rate of a metabolic process. Sachs (1860) identified three crucial values for each factor, referred to as the cardinal values or magnitude points. These are the minimal, optimal, and maximal values. The cardinal minimum value is the factor magnitude below which the metabolic process cannot proceed.
The optimal value is the one at which the metabolic process is most rapid. The maximum is the magnitude of a factor at which the process comes to a halt. A metabolic process’ rate declines at magnitudes below and above the optimum until the minimum and maximum values are attained.

Viruses: Reproduction, Transmission, Viroids, and Prions

Viroids: The Viroids were discovered by Diener in 1971. The Viroids are infectious RNA particles. The capsid protective covering is absent. The molecular weight of viroids is in the range of 115,00 – 130,000 daltons. It contains circular RNA particles and is the smallest pathogens known. The viroids cause diseases in plants i.e they are pathogenic to plants only. E,g PSTD – potato spindle tuber disease, Citrus exocortis, Cucumber pale yellow.

Viruses: Meaning, Features, and Components

What form of the Virus is a Bacteriophage
The Bacteriophage refers to eaters of bacteria as they destroy bacteria. The Bacteriophages are obligate parasites and are found in habitats where bacteria can survive. The bacteriophages are also referred phages. the phages are known to occur in all bacteria. Most of the work has been done on the phages that attack Escherichia.
Structure of Bacteriophage
It is named the Loli-Pop Construction. This form has a head and tail. It is also named Tadpole Construction. The tail in addition to the head is present. The tail is elongated, the head and tail are joined together with the help of the collar and neck. Around the tail, there is the presence of a sheath that is contractile from six edges, there is the presence of tail fibers on the lower side plate. there is the presence of structures called tail pins. so there are six tail fibers and six tail pins.

Noise Pollution: Definition, Causes, and Control

Noise pollution can be controlled by educating people on its dangerous effects. Decibel meters may be installed in zones susceptible to noise pollution so that the public may assist in controlling noise pollution. A dense evergreen hedge can reduce noise by 10 db. Border planting of trees along highways effectively controls pollution by vehicular traffic. A 20 ft extensive plantation across the homes protects them from noise pollution.

Water pollution: Definition, Causes, and Agents

Pesticides: are chemical materials utilized by humans to govern pests, those living organisms thought to be dangerous to human interests. Most of the pesticides are poisonous and aim to kill the target species. Pesticides are used globally and in extensive sort of habitats. The extra continual disperse into all environments inclusive of the ones which might be by no means sprayed, e,g the open oceans and subpolar regions. Most of the life on earth is thus in touch with insecticides. The critical ecological traits of insecticides are toxicity, persistence, and their non-precise and density-impartial mode of action. Pesticide applications as dust and sprays lead to their wide dispersal in air, water, and incorporation into food chains in non-target areas. Bio-magnification due to DDT poisoning has devastating effects on top carnivores, especially on predatory birds. These birds are especially vulnerable because DDT includes hormonal changes that affect calcium metabolism and result in thinner eggshells that are liable to break easily. This led to a decline in the population of birds, Lillie osprey, bald eagles, falcons, peregrine, etc. Fishes are also affected substantially since they directly absorb DDT from the surrounding through the gills as well as by their food intake.

Ecological Niche: Definition, sorts, and Examples

Mutualism is an unavoidable touch that benefits each species substantially. This interaction is now and then called a symbiosis (i.e. mutualism), However, symbiosis sincerely refers to the close affiliation of two or more distinctive species, irrespective of benefits or lack, thereof, and therefore covers mutualism, commensalism, and parasitism. Mutualism may be facultative, which means the species can exist independently of one another, or obligatory, which means the connection is vital for one or each species to survive.