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Greenhouse Effect

What is the Greenhouse Effect?


Life on earth depends on energy from the sun. About 30 percent of the sunlight that beams toward Earth is deflected by the outer atmosphere and scattered back into space. The rest reaches the planet's surface and is reflected upward again as a type of slow-moving energy called infrared radiation.
The heat caused by infrared radiation is absorbed by "greenhouse gases" such as water vapor, carbon dioxide, ozone and methane, which slows its escape from the atmosphere.
Although greenhouse gases make up only about 1 percent of the Earth's atmosphere, they regulate our climate by trapping heat and holding it in a kind of warm-air blanket that surrounds the planet.
This phenomenon is what scientists call the "greenhouse effect." Without it, scientists estimate that the average temperature on Earth would be colder by approximately 30 degrees Celsius (54 degrees Fahrenheit), far too cold to sustain our current ecosystem.
How Do Humans Contribute to the Greenhouse Effect?
While the greenhouse effect is an essential environmental prerequisite for life on Earth, there really can be too much of a good thing.
The problems begin when human activities distort and accelerate the natural process by creating more greenhouse gases in the atmosphere than are necessary to warm the planet to an ideal temperature.
  • Burning natural gas, coal and oil -including gasoline for automobile engines-raises the level of carbon dioxide in the atmosphere.
  • Some farming practices and land-use changes increase the levels of methane and nitrous oxide.
  • Many factories produce long-lasting industrial gases that do not occur naturally, yet contribute significantly to the enhanced greenhouse effect and "global warming" that is currently under way.
  • Deforestation also contributes to global warming. Trees use carbon dioxide and give off oxygen in its place, which helps to create the optimal balance of gases in the atmosphere. As more forests are logged for timber or cut down to make way for farming, however, there are fewer trees to perform this critical function.
  • Population growth is another factor in global warming, because as more people use fossil fuels for heat, transportation and manufacturing the level of greenhouse gases continues to increase. As more farming occurs to feed millions of new people, more greenhouse gases enter the atmosphere.
Ultimately, more greenhouse gases means more infrared radiation trapped and held, which gradually increases the temperature of the Earth's surface and the air in the lower atmosphere.

The Average Global Temperature is Increasing Quickly

Today, the increase in the Earth's temperature is increasing with unprecedented speed. To understand just how quickly global warming is accelerating, consider this:
During the entire 20th century, the average global temperature increased by about 0.6 degrees Celsius (slightly more than 1 degree Fahrenheit).
Using computer climate models, scientists estimate that by the year 2100 the average global temperature will increase by 1.4 degrees to 5.8 degrees Celsius (approximately 2.5 degrees to 10.5 degrees Fahrenheit).


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12 “Superfoods” You Should be Eating Now


"Superfoods” are foods packed with nutrients that offer various health benefits, and have few if any negative properties. It’s not a medical term, but one that’s emerged more popular culturally. Since it’s best to load up on your vitamins through diet rather than through expensive vitamins, it’s always a great idea to reach for “superfoods,” and we’ve outlined the ones that are particularly good for women in their 20s and 30s. While these multitasking foods won’t make your Spidey senses tingle (or, maybe they will: read below about edamame), they may help to ward off diseases such as cancer, heart disease, Alzheimer’s and osteoporosis.    


Apples


Fiber-rich apples are a great food to help you feel fuller longer while providing you with a necessary dose of pectin, a soluble fiber. It’s believed that pectin reduces blood pressure, cholesterol, and the risk of colon cancer, breast cancer, and diabetes.    


Cranberries


You may know to gulp down cranberry juice if you’re suffering from a urinary tract infection (as a compound in cranberry juice helps to flush bacteria from the urinary tract), but did you know that cranberries also help to reduce cholesterol? Eat them dry, fresh, ground, as a salad topping, in a smoothie, or drink natural cranberry juice. Now that’s what we call versatility.       


Tomatoes


Tomatoes are loaded with the antioxidant lycopene, and they’re thought to play a role in protecting the skin against damage that leads to skin cancer--cases of which have soared recently in young women. Apart from that, tomatoes are rich in vitamin C, which can give your immune system a boost.    


Kale


While the research is still developing, kale may help to prevent breast and ovarian cancers. Researchers think that kale’s phytonutrients may cause the body to make enzymes that combat cancer-causing substances. If you need further evidence to try out this multi-purpose green, it’s also great for providing you with vitamin C, potassium and calcium. Remember, in your 20s and 30s you still need lots of calcium to build your bone mass to prevent osteoporosis.      


Blueberries


Blueberries aren’t just delicious, they may protect you against cancer and dementia, and can even neutralize free radicals that cause cell damage. That is, the nutrition in blueberries can help to protect the skin against prematurely aging (we knew that would perk you up!).    


Turkey


While it’s the showstopper at Thanksgiving, consider eating turkey regularly year round. In terms of superfood criteria, the selenium in lean turkey breast meat will help boost your immune function. Need more reason? It contains niacin and vitamins essential for energy production.    


Eggs


Women in their 20s and 30s disproportionately suffer from low iron levels that can lead to anemia, which can leave you feeling tired and low energy. Eggs are not only a great source of protein to start your day off right, but they also combat anemia because they are rich in iron. An added bonus: eggs have biotin and vitamin B-12, which can help make your mane lovelier by strengthening your hair.     


Spinach


Popeye was on to something with his obsession with this superfood, which is rich in vitamin K, vitamin A, magnesium, folate, manganese, iron, calcium, vitamin C, vitamin B2, potassium, and vitamin B6. Spinach also provides antioxidants (via flavonoids), is anti-inflammatory, aids digestion, and helps lower the effects of stress in the body (via magnesium). Perfect, since being in your 20s and 30s may be fun, but it’s a crazy stressful time of life.    


Quinoa


Quinoa is a whole grain that’s an excellent source of fiber and even has protein, so it’ll help you feel fuller for longer. Quinoa’s fiber and whole grain helps to prevent high cholesterol, and since it’s also rich in zinc, it’s thought to protect against stroke and cancer.     


Salmon


While salmon has omega-3 fatty acids, the key ingredient here is the DHA (docosahexaenoic acid). Your body can use DHA to protect its cellular membranes, which can help combat depression, cardiovascular disease, strokes, hypertension, and Alzheimer’s. And did you know taht omega-3 fatty acids are great for keeping mucous membranes in tip top shape--dry eyes remedy, anyone?     


Pistachios


Pistachios pack a wop of antioxidants your body needs to reduce cholesterol and even help reduce stress in some situations. In addition, they’re a great source of iron, calcium and potassium. If you’re looking to meet protein needs, pistachios will give you more than any other nut (apart from almonds). At snack time, go for unsalted in shells. And those shells are actually a good thing, since the time it takes to crack and eat each pistachio will make you more conscious of portion size (probably why we’ve heard pistachios be referred to as “the skinny nut”).    


Edamame


Folate isn’t just important for expectant mothers, but for all women of childbearing age. It’s even been shown to ward off grey hair in some cases. For a healthy folate-rich snack, steam edamame or sprinkle it onto a salad. Some have even pointed to edamame as something of an aphrodisiac. Looks like you may want to head to a sushi restaurant for your next date night…    

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Why is Smoking is Bad for Health?

"Smokers never become old because they die younger."

This saying reveals a harsh fact about the hazardous effects of smoking. There are millions of people who are addicted to cigarette smoking throughout the world. Why do people start smoking? Well, there are several different reasons for smoking. Some people start smoking in their teens just for the sake of the thrill and sometimes, it's peer pressure. Eventually, they become addicted to the nicotine present in cigarettes. Some people smoke to get relief from stress.

People with low self-esteem become more addicted to smoking. Whatever the reason, once a person gets addicted to smoking, he/she has to face a number of serious health problems. Let's take a look at what are some of the health complications that an average smoker is exposed to.

Diseases Caused Due to Smoking

There are several harmful health effects of cigarette smoking. A person addicted to smoking may suffer from a number of serious and fatal diseases. Smokers are more likely to suffer from respiratory infections and several minor complaints such as coughand cold. Smokers may suffer from some dreadful diseases such as cancer, heart, cardiovascular and lung diseases. Also caused, are respiratory problems and several other problems related to the kidneys, liver and pancreas.

Cancer: Smokers are at a higher risk of getting cancer than non-smokers. Carcinogens, such as tar, present in tobacco smoke, can cause cancer of the lungs, mouth, throat and gullet. Mouth cancer, which is a highly common occurrence among smokers, starts off usually on one's lips or underneath the tongue. About 90% of lung cancer cases are due to smoking. Female smokers are at a greater risk of getting cervical cancer. Smokers can also develop other types of cancers such:

  • Larynx cancer
  • Acute myeloid leukemia
  • Stomach cancer
  • Kidney cancer
  • Lung cancer
  • Pharynx cancer
  • Esophagus cancer
  • Oral cavity cancer
  • Bladder cancer
  • Pancreatic cancer
It has been observed that smokers who've smoked earlier in life, and light up many times in a single day, are at a higher risk of getting lung cancer. A startling yet interesting fact, is that ex-smokers have about 15 years before they are cleared from the high risk of getting lung cancer.

Cardiovascular Diseases: These are diseases of the heart, its blood vessels, and other related organs. Coronary disease is a major cause of death related to smoking. Nicotine present in tobacco, increases cholesterol levels in the blood, getting clogged within the arteries; causing a hardening in the arteries. The arteries become narrow, rigid, or blocked.

Due to atherosclerosis (narrowing of arteries), blood clots are formed, thus increasing the risk of having a cardiovascular disease. Common cardiovascular diseases found in smokers are coronary thrombosis, cerebral thrombosis, coronary heart diseases, blockage in the legs (peripheral vascular disease) and cerebrovascular diseases such as stroke. Smoking can also cause what is called abdominal aortic aneurysm, which is a condition where the aorta swells up or weakens; this is a major artery in the body.

Respiratory Conditions: COPD or Chronic Obstructive Pulmonary Disease, is a group of health conditions that block airflow, thus making it difficult to breath. It causes health problems such as emphysema and chronic bronchitis. Emphysema is breathlessness caused by damage to the alveoli (air sacs). Chronic bronchitis causes frequent coughing with a lot of mucus.

Smoking increases the rate of decline in lung function to three times its usual rate. Breathlessness starts due to regression of lung functions. For runners who smoke, this habit can cause breathlessness and difficulty in breathing, since the lungs have to work harder than usual. This can cause one to run out of air within minutes, not making it as effective if one were a non-smoker.

Other Conditions Caused by Smoking
  • Smoking causes an acidic taste in the mouth. It can increase the risk of developing mouth ulcers.
  • The chemicals present in tobacco damage the lining of the blood vessels and affect the levels of fat in the bloodstream. It increases the risk of atheroma, which is the main cause of heart disease, strokes, and aneurysms.
  • Smoking deteriorates oral health, leading to stained teeth and gums. Smoking can give rise to various health problems of the gums and teeth, such as swollen gums, loose teeth, and bad breath.
  • Smoking can give rise to various sexual problems. People addicted to smoking are more likely to face fertility and sexual performance issues.
  • Smoking increases the risk of high blood pressure which is a risk factor for stroke and heart attacks.
  • Smoking worsens asthma in patients who smoke, increasing the inflammation of the airways.
  • Smoking can cause premature aging. Due to smoking, the blood supply to the skin is reduced, thus reducing the levels of vitamin A. Hence, smokers have paler skin and more wrinkles.
  • Women who smoke, increase the chances of suffering from hip fractures, than non-smoking women. This is because women who smoke have a lower bone density, like in postmenopausal women.
  • Heavy smoking causes macular degeneration which results in gradual loss of eyesight. Smokers are also at a higher risk of cataract.
  • Some other conditions caused by smoking are chest infections, diabetic retinopathy, tuberculosis, multiple sclerosis and Crohn's disease.
  • There are even passive effects of smoking, which can be quite dangerous to the non-smokers in the company of smokers. If babies and kids come in contact with smokers, they are highly prone to asthma and infections of the ear, nose, and chest. They are also at a high risk of Sudden Infant Death Syndrome (dying while asleep).
Effects of Smoking During Pregnancy

A pregnant woman who frequently smokes is at a higher risk of a miscarriage and other complications such as bleeding, detachment of placenta, and ectopic pregnancy. There is a possibility of giving birth to a baby with a low birth weight, or a stillborn baby. There may be some congenital defects in the baby (for instance, a cleft palate). Mothers who smoke can also suffer from preterm delivery and infertility issues.

Summary of Why Smoking is Dangerous

It is estimated that every minute about 7 people die due to tobacco use. According to researches, tobacco in a cigarette contains more than 400 toxic substances and 4,000 chemical compounds. Let us see how harmful smoking such substances can be.
  • The most hazardous substances in cigarettes are tar (which is a carcinogen), nicotine (which increases cholesterol levels in the body) and carbon monoxide (which decreases the amount of oxygen within the body).
  • Nicotine is the most addictive substance in tobacco. Smoking decreases the level of oxygen from reaching the tissues, giving rise to different health problems such as strokes, heart attacks or miscarriages.
  • It increases cholesterol levels in the blood, thus increasing the risk of heart attacks.
  • Smoking causes damage and constriction of blood vessels, leading to various diseases of blood vessels.
  • Smoking also causes chronic coughing, shortness of breath, premature aging, recurrent infections and reduced overall fitness.
  • Smoking-related deaths are mainly because of heart diseases, cancers and COPD (chronic obstructive pulmonary disease).
Smoking adversely affects the health of a smokers and of those around them. The only way to prevent these health hazards is to quit smoking. It's never too late to stop smoking. It could protect you and your family from many fatal diseases. After all, health is wealth, isn't it?



 
 
 
 
 

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6 Reasons to Avoid Soy Milk

The soybean is a rich form of protein and other nutrients that has been the basis of several Asian dishes for thousands of years. It wasn’t a big stretch for the industry to claim that, if a whole food is so good, then surely the concentrated juice of this food must be even better. It certainly caught the imagination of many of the baby boomer generation and they enthusiastically embraced the new “milk without guilt”. Soy growers contribute a substantial levy which is used to market soy products and the marketing has been a major success story with soy milk sales in the US rising from two million dollars in 1980 to 300 million dollars last year. The problem was that no one told the health-minded consumers that the Asians wouldn’t touch soy milk with a barge pole. They understood that there were some problems with this legume so they only ate it in fermented form, i.e. lacto-fermentation neutralises the negatives associated with soy products. So what is wrong with this ‘miracle health food’? Let’s look behind the big budget advertising.

A beautiful soy crop - Ready for harvest
A beautiful soy crop - Ready for harvest

Six Serious Soy Problems

I) Soy milk is one of the highest known
sources of phytates.

Phytic acid is a natural acid found in cereal grains and legumes which inhibits the uptake of important minerals like zinc, magnesium and calcium. The body contains relatively large amounts of magnesium and calcium but very low stores of the trace mineral, zinc. The vast majority of us are deficient in zinc and yet this is the main mineral involved in the health of the prostate gland and prostate cancer is set to become the largest killer of Australian men. Zinc is also linked to breast health and it is essential for the thymus gland and the associated production of killer T cells for the immune system. Zinc is often called “the intelligence mineral” because it also plays a major role in the development and health of the brain and central nervous system. Phytates form insoluble zinc phytates so it is always best to supplement your zinc directly before bed. This ensures that it doesn’t conflict with phytic acid in your breakfast cereal or your lunchtime sandwich.

2) Soy milk contains huge amounts of
enzyme inhibitors.

If Dr Edward Howell is correct then we are born with a certain capacity to produce enzymes and when we have exhausted our enzyme capacity then we die. Every time we eat cooked food we withdraw from this bank account, as opposed to consumption of raw food which contains the enzymes which help to digest it. Every function from breathing to thinking to digesting is enzyme-dependent. If we over-stress the digestive system then metabolic enzymes from the immune system or detox system, for example, are directed to help out with digestion. The very worst thing we can do is to speed up the ‘use by’ date of our enzyme capacity by consuming foods or taking drugs which inhibit this precious workforce. Aspirin is a serious enzyme inhibitor, for example, even when it is taken at low doses to thin the blood. The soya bean contains very high levels of enzyme inhibitors to help prevent premature germination. The most important enzyme affected is trypsin which is involved in the digestion of protein. As a result, soy products can lead to gastric distress, reduced protein digestion and serious deficiencies in amino acids. Animal research has shown that diets high in trypsin inhibitors are linked to serious pancreatic disorders, including cancer. Soy milk effectively concentrates the enzyme inhibitors found in the bean.

3) Soy milk contains haemagglutinin which
compromises delivery of cellular oxygen.



Haemagglutinin is a clot-promoting substance which causes red blood cells to clump together. This, in turn, limits the capacity of these cells to absorb oxygen for delivery around the body and can compromise heart health. Haemagglutinin and enzyme inhibitors are both growth depressors so it is incomprehensible that infant formulas are so often based on soy milk. It becomes blatant stupidity when you understand that soy milk is also a goitrogen (causing enlargement of thyroid gland).

4) Soy milk negatively affects the health
of the thyroid gland.

Soy milk contains genistein which can do irreversible damage to the enzymes that synthesise thyroid hormones. In 1991 Japanese researchers found that as little as 30 grams of soy beans per day for one month resulted in a significant increase in the thyroid stimulating hormone. In fact, several of their subjects developed diffuse goitre and hyper thyroidism and complained of constipation, fatigue and lethargy, even though their intake of iodine was adequate.

5) Soy milk contains unacceptably high
levels of aluminium.



The soy bean is an aluminium accumulator and as a result soy milk contains 100 times more aluminium than cow’s milk. Aluminium has been heavily implicated in the current plague of Alzheimers Disease. Alzheimers now affects one person in four, over the age of 65. Unlike cow’s milk, soy milk is a highly processed material. Soybeans are first mixed with an alkaline solution to remove fibre, then precipitated and separated using an acid wash and, finally, neutralised in an alkaline solution. Acid washing in aluminium tanks leaches aluminium into the end-product. Soy-based formula contains over 1000% more aluminium than conventional, milk-based formula due to the concentrating effect of the powdering process. During the spray drying process, used to create the high protein powder, unacceptable levels of nitrates are formed and a toxin called lysinoalanine is also formed during the alkaline stage of the processing. In the US, if you are unlucky enough to live there, 99% of the soy is genetically modified and it is also one of the most chemical intensive of the broadacre crops in that country. You wouldn’t think that the soy milk formula vs. the breast milk debate would be too hard considering these facts.

6) Soy milk features high levels of phytoestrogens which are proven endocrine disruptors.

Soy contains isoflavones which are currently being researched in relation to treatment for osteoporosis, relief of menopausal symptoms, cancer prevention and heart disease. It sounds an impressive list and you might argue that ‘what could be wrong with consuming these compounds every day in your food?’. The problem relates to balance, a key factor influencing the health of plants, animals and humans. While isofavones are powerful compounds with undeniable medicinal potential, like any medicine, they should only be used for short periods to address specific issues. When we consume them, in concentrated form, on a daily basis, they can become both disruptive and dangerous. When toxicologist, Dr Mike Fitzpatrick, conducted an extensive literature review of soy research, he was shocked to find that consumption of this vegan “wonder food” has been linked to numerous disorders. He found that the phytoestrogen, genistein, had been linked to endocrine disruption in animals, in studies dating right back to the 1950′s. He also discovered research confirming links to infertility, increased cancer and infantile leukemia. Some US commentators are even suggesting that soy has the potential to become the next asbestos. In a recent New York Times feature article, the author, a previous soy supporter, begrudgingly admitted that “not one of the 18 scientists interviewed for this article was willing to say that taking isoflavones was risk free”.

In Conclusion

Both margarine and soymilk are examples of the opportunistic bastardisation of whole foods in pursuit of profit. There has never been a single example where industrial manipulation of whole foods has not seriously compromised the nutritional integrity of that food. At some point, perhaps, we will finally recognise that science cannot improve on the original when it comes to food. Food has been sacred in every society prior to ours and the bombarding of our food with massive amounts of radiation is about as far removed from sacred appreciation as is possible. Removing margarine, soymilk and microwaves from your kitchen is a good start to reclaiming vitality in your diet.

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Cytokinesis


Cytokinesis

Cytokinesis is the process by which a cell divides its cytoplasm to produce two daughter cells. As the final step in cell division after mitosis , cytokinesis is a carefully orchestrated process that signals the start of a new cellular generation. The separation of one cell into two is accomplished by a structure called the contractile ring. The contractile ring is a structure believed to operate in a way similar to muscle. A molecular motor, myosin, contracts the actin filaments that form the contractile ring tighter and tighter until the cell is pinched in two. The contraction of the contractile ring has been likened to tightening a purse string to close the top of a pouch. The furrow created by this pinching process is also called the "cleavage furrow," as it is the site at which cleavage of one cell into two cells occurs.
Cytokinesis consists of four major steps. The first step is to define the position at which the contractile ring will form. The spindle, the structure responsible for segregating the chromosomes into what will become the daughter cells, also appears to be responsible for defining where the contractile ring forms. The contractile ring forms perpendicular to the long axis of the spindle at its midpoint. Components of the spindle that come in contact with the plasma membrane, called astral microtubules, are believed to transmit a signal to the cell periphery that tells actin and other components of the contractile ring to assemble at that location. Actin and microtubules are both part of the cytoskeleton .
The second step in cytokinesis is to assemble the actin filaments that form the contractile ring. Additional proteins , including the molecular motor myosin, which powers contraction, also assemble in this same domain. The third step is the actual contraction of the contractile ring. In this step, the myosin motor, powered by adenosine triphosphate, moves the actin filaments past each other, much in the same way as myosin interacts with actin to power the contraction of muscle. This step also requires the removal of actin subunits to allow the ring to decrease in size. The final step, breaking and refusion of the plasma membrane, occurs once the ring has contracted to its minimum size. This breaking and fusion finally separates the two daughter cells from each other.
As with each of the steps in mitosis, cytokinesis is highly regulated. If the cell were to divide its cytoplasm prior to the completion of duplication and segregation of the chromosomes, it is unlikely that each of the progeny cells would receive the proper genetic information. Thus the cell employs several regulatory mechanisms to assure that cytokinesis occurs only after all of the chromosomes have been properly segregated. There is, for example, a "spindle checkpoint" that assures that each and every chromosome has attached to the spindle. The entire process of cell division waits at the checkpoint until the conditions of the checkpoint have been satisfied. Once they have been, the process continues and concludes with cytokinesis.

Cytokinesis in Animal Cells

The first step in cytokinesis in animal cells is the contractile ring positioning. The difference between cytokinesis in plants and animals arises from this stage itself. Animal cell cytokinesis begins just after the onset of sister chromatid separation in the anaphase of mitosis. A contractile ring that is made of non-muscle myosin II and actin filaments, assembles equatorially, that is, in the middle of the cell, at the cell cortex. The cell cortex is adjacent to the cell membrane. Myosin II uses the free energy released when ATP is hydrolysed to move along these actin filaments, thus, constricting the cell membrane to form a cleavage furrow towards the middle. The continuing hydrolysis causes this cleavage furrow to ingress, that is, move inwards. This process is visible with the help of a light microscope. Ingression continues until a midbody structure that is composed of electron-dense, proteinaceous material is formed and the process of abscission then physically cleaves this midbody into two.

The abscission depends on septin filaments beneath the cleavage furrow, which provides a structural basis to ensure completion of cytokinesis. After cytokinesis, non-kinetochore microtubules reorganize and disappear into a new cytoskeleton as the cell cycle returns to the interphase. The position at which the contractile ring assembles is dictated by the mitotic spindle. Simultaneous with contractile ring assembly during prophase, a microtubule based structure called the central spindle forms when non-kinetochore microtubule fibers are bundled between the spindle poles. Cytokinesis must be a controlled procedure so as to ensure that it occurs only after sister anaphase separation during normal proliferative cell divisions. To achieve this purpose, many components of the cytokinesis machinery are highly regulated so as to ensure that they are able to perform a specific function at only a specific stage of the cell cycle.

 


Cytokinesis in Plant Cells

As mentioned earlier, cytokinesis in plants and animals is basically different from each other due to the presence of cell wall, which is one of the plant cells parts. Rather than forming a contractile ring, plant cells form a cell plate in the middle of the cell. The Golgi apparatus releases vesicles that contain cell wall materials. These vesicles fuse at the equatorial plane to form the cell plate. The cell plate initially begins as a fusion tube network, which then becomes a tubulo-vesicular network as more and more components are added.

There is only one exception to the process of cytokinesis, which is in the case of oogenesis, which is the process where an ovum is created in the ovarian follicle of the ovary. Here, the ovum takes up almost all the cytoplasm and organelles, thus, leaving very little for the resulting polar bodies which eventually die. Thus, there is no division of the cytoplasm per se. However, in all other cells, irrespective of whether they are plant cells or animal cells, cytokinesis is the method by which the cell divides into two.
 

 
 
 
 
 
 


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Tissue Culture


Tissue culture is a process that involves exposing plant tissue to a specific regimen of nutrients, hormones, and light under sterile, in vitro conditions to produce many new plants, each a clone of the original mother plant, over a very short period of time. AgriForest's tissue culture plants are characterised by disease free growth, a more fibrous, healthier root system, a bushier branching habit, and a higher survival rate.
There are three main steps to the tissue culture process:


STAGE I is the initiation phase. It concerns the establishment of plant tissue in vitro by sterilising the material and initiating it into culture.


STAGE II is the multiplication phase. At this stage, the in vitro plant material is re-divided and placed in a medium with plant growth regulators that induce the proliferation of multiple shoots. This process is repeated many times until the number of plants desired is reached.


STAGE III is the root formation phase. It involves the introduction of hormones to induce rooting and the formation of complete plantlets.

Following these three stages, the plants are then moved from the laboratory to the greenhouses for acclimatisation and further development.



 
 
 
 

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Phagocytosis Process In Amoeba

Phagocytosis

Phagocytosis is a process used by certain cells to engulf and ingest solid particles. The particles engulfed and ingested can be nutrient particles or bacteria. The cells capable of ingesting in such a manner, by the phagocytosis process, are known as phagocytes. The phagocytes can be free living unicellular organisms, such as amoeba, or they can be part of the body cells of a multicellular organism. Phagocytes belongs to the family of processes, that are collectively referred to as 'endocytosis', consisting of all the processes that involve ingestion of material by cell.

What is the Process of Phagocytosis :

Phagocytosis process is a specific type of endocytosis, that involves vesicular internalization of solid particles, such as bacteria, unlike other endocytosis process that involve vesicular internalization of liquids. Certain unicellular organisms, such as the protists, use this particular process as means of feeding. It provides them part or all of their nourishment. This mode of nutrition is known as phagotrophic nutrition. In amoeba, phagocytosis takes place by engulfing the nutrient with the help of pseudopods, that are present all over the cell, whereas, in ciliates, a specialized groove or chamber, known as the cytostome, is present, where the process takes place.

Other examples of phagocytosis include some immune system cells, that engulf and kill certain harmful, infectious micro-organisms and other unwanted foreign materials. Mammalian immune system contains certain phagocytes that helps them to destroy and get rid of pathogenic bacteria and other infectious organisms. In these cells, the engulfment of foreign material is facilitated by actin-myosin contractile system. It allows the cell membrane to expand in order to engulf the particle and then contract immediately, ingesting it.

Phagocytosis Steps :
It is quite fascinating to watch the process under a microscope. One can actually see the phagocyte engulfing the foreign particle. There are several distinct steps involved in the process of phagocytosis. Let us have a look at them.

In case of unicellular organisms, the process of phagocytosis takes place when the organism comes in contact with the nutrient particles. The phagocytes in the immune system are activated in the presence of certain bacterial cells, inflammatory cells or other foreign bodies. Let us talk about the general steps involved in the process.

Step 1: The phagocytes get activated by the presence of certain particles around them. As soon as they detect a foreign particle, the phagocytes produce surface glycoprotein receptors, that increase their ability to adhere to the surface of the particle.

Step 2: The phagocyte slowly attaches to the surface of the foreign particle. The cell membrane of the phagocyte begins to expand and forms a cone around the foreign particle.

Step 3: The cell membrane surrounds the foreign particle from all sides to create a vacuole, known as phagosome or food vacuole. The phagosome is then passed into the cell for absorption.

Step 4: Now comes the role of the lysosomes, which are cell structures, that are specialized in digesting the particles that enter the cell through the cell membrane. The lysosomes break the food vacuole or phagosome, into its component materials. The essential nutrients, if any, are absorbed in the cell, and the rest is expelled as waste matter. In case of the immune system, the cell creates a peroxisome, a special structure that helps the body to get rid of the toxins.

In unicellular organisms like amoeba, phagocytosis is necessary for survival, as they are totally dependent on it for nutrients. Some of these organisms have adapted special traits which enable them to locate and keep a track of the food particles.
 
 
 
 
 
 
 
 
 
 
 
 
 


 

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