WHAT IS HIV?

Posted by: Ananya Bhardwaj

Many people (not just kids, but adults, too) don't understand how HIV and AIDS are related, even though they hear these two words used together all the time.


HIV stands for humanimmunodeficiency (say: im-yuh-noh-di-fish-un-see) virus. AIDS stands for acquired immunodeficiency syndrome. HIV is actually the virus that causes the disease AIDS.

HIV Hurts the Immune System

People who are HIV positive have been tested and found to have signs of the human immunodeficiency virus in their blood. HIV destroys part of the immune (say: ih-myoon) system. Specifically, it affects a type of white blood cell called the T lymphocyte (say: lim-fuh-site), or T cell. T cells are one type of "fighter" cell in the blood that help the body fight off all kinds of germs and diseases.

After HIV enters the body, it piggybacks onto a T cell and works its way inside of that cell. Once inside, the virus completely takes over the T cell and uses it as a virus-making factory to make a lot of copies of itself. The newly made viruses then leave the T cell and go on to infect and destroy other healthy T cells as they continue to multiply inside the body. T cells invaded by the virus can no longer properly fight infections.

Someone who is infected with the virus is called HIV positive. But it may take years for the virus to damage enough T cells for that person to get sick and develop AIDS. Although the HIV-positive person may feel fine, the virus is silently reproducing itself and destroying T cells.

However, thanks to new medications, someone infected with HIV can stay relatively healthy and symptom-free for many years. These medications are very expensive and not available to everyone in the world.

When the person's immune system has weakened and more of the blood's T cells have been destroyed by the virus, the person can no longer fight off infections. This is when he or she gets very sick. A doctor diagnoses someone with AIDS when the person has a very low number of T cells or shows signs of a serious infection.

Source: http://kidshealth.org/en/kids/hiv.html

Difference between Prokaryotic and Eukaryotic Cell!

Prokaryotic and Eukaryotic Cell

Post by Ananya Bhardwaj

Definition of eukaryotes and prokaryotes

Prokaryotes (pro-KAR-ee-ot-es) (from Old Greek pro- before + karyon nut or kernel, referring to the cell nucleus, + suffix -otos, pl. -otes; also spelled "procaryotes") are organisms without a cell nucleus (= karyon), or any other membrane-bound organelles. Most are unicellular, but some prokaryotes are multicellular.

Eukaryotes (IPA: [juːˈkæɹɪɒt]) are organisms whose cells are organized into complex structures by internal membranes and a cytoskeleton. The most characteristic membrane bound structure is the nucleus. This feature gives them their name, (also spelled "eucaryote,") which comes from the Greek ευ, meaning good/true, and κάρυον, meaning nut, referring to the nucleus. Animals, plants, fungi, and protists are eukaryotes.

Differences Between Eukaryotic and Prokaryotic Cells

The difference between the structure of prokaryotes and eukaryotes is so great that it is considered to be the most important distinction among groups of organisms.

• The most fundamental difference is that eukaryotes do have "true" nuclei containing their DNA, whereas the genetic material in prokaryotes is not membrane-bound.

• In eukaryotes, the mitochondria and chloroplasts perform various metabolic processes and are believed to have been derived from endosymbiotic bacteria. In prokaryotes similar processes occur across the cell membrane; endosymbionts are extremely rare.

• The cell walls of prokaryotes are generally formed of a different molecule (peptidoglycan) to those of eukaryotes (many eukaryotes do not have a cell wall at all).

• Prokaryotes are usually much smaller than eukaryotic cells.

• Prokaryotes also differ from eukaryotes in that they contain only a single loop of stable chromosomal DNA stored in an area named the nucleoid, while eukaryoteDNA is found on tightly bound and organised chromosomes. Although some eukaryotes have satellite DNA structures called plasmids, these are generally regarded as a prokaryote feature and many important genes in prokaryotes are stored on plasmids.

• Prokaryotes have a larger surface area to volume ratio giving them a higher metabolic rate, a higher growth rate and consequently a shorter generation time compared to Eukaryotes.

• Genes
• Prokaryotes also differ from eukaryotes in the structure, packing, density, and arrangement of their genes on the chromosome. Prokaryotes have incredibly compact genomes compared to eukaryotes, mostly because prokaryote genes lack introns and large non-coding regions between each gene.
• Whereas nearly 95% of the human genome does not code for proteins or RNAor includes a gene promoter, nearly all of the prokaryote genome codes or controls something.
• Prokaryote genes are also expressed in groups, known as operons, instead of individually, as in eukaryotes.
• In a prokaryote cell, all genes in an operon(three in the case of the famous lac operon) are transcribed on the same piece of RNA and then made into separate proteins, whereas if these genes were native to eukaryotes, they each would have their own promoter and be transcribed on their own strand of mRNA. This lesser degree of control over gene expression contributes to the simplicity of the prokaryotes as compared to the eukaryotes.
• Source: http://www.diffen.com/difference/Eukaryotic_Cell_vs_Prokaryotic_Cell

LEARN ABOUT YOUR AMAZING BODY!!!!!!

 Every day on a average of 3 times we eat delicious food. We have our own favourite cuisine, our own favourite combination of food, our own favourite drinks.
But have you ever wonder what happens to the food once we ate it. Surely it's not going to sit around in our stomach for whole life. If that have to happen than we only need to eat food once in our lifetime. Why waste our precious money on food....

In this short video I had tried to explain the whole process of digestion and the digestive system in simple language. Hope you guys enjoy it and learn something new from it...

Let know about us

We all are B.Ed student studying in SPM college and our brief introduction is as given below

Priyanka Rao
B.Sc. Zoology (Hons), Kirori Mal College 

Sudha Beng 

B.Sc. Life Science, Swami Shraddhanand College

Anushka Singh 

B.Sc Biology (Hons), MJPRU, Barielly 

Ananya Bhardwaj

B.Sc. Zoology (Hons), SGTB Khalsa College

There's biology in everything, even when you're feeling spiritual.--------Helen Fisher

"The starting point of all achievement is desire." 
---- Napoleon Hill

Zika Virus: A great threat after ISIS

Zika virus

Key facts

• Zika virus disease is caused by a virus transmitted by Aedes mosquitoes.
• People with Zika virus disease usually have symptoms that can include mild fever, skin rashes, conjunctivitis, muscle and joint pain, malaise or headache. These symptoms normally last for 2-7 days.
• There is no specific treatment or vaccine currently available.
• The best form of prevention is protection against mosquito bites.
• The virus is known to circulate in Africa, the Americas, Asia and the Pacific.

Introduction

Zika virus is an emerging mosquito-borne virus that was first identified in Uganda in 1947 in rhesus monkeys through a monitoring network of sylvatic yellow fever. It was subsequently identified in humans in 1952 in Uganda and the United Republic of Tanzania. Outbreaks of Zika virus disease have been recorded in Africa, the Americas, Asia and the Pacific.

• Genre: Flavivirus
• Vector: Aedes mosquitoes (which usually bite during the morning and late afternoon/evening hours)
• Reservoir: Unknown

    History of Zika Virus  

    Structure of Zika virus 

Signs and Symptoms

The incubation period (the time from exposure to symptoms) of Zika virus disease is not clear, but is likely to be a few days. The symptoms are similar to other arbovirus infections such as dengue, and include fever, skin rashes, conjunctivitis, muscle and joint pain, malaise, and headache. These symptoms are usually mild and last for 2-7 days.

Potential complications of Zika virus disease

During large outbreaks in French Polynesia and Brazil in 2013 and 2015 respectively, national health authorities reported potential neurological and auto-immune complications of Zika virus disease. Recently in Brazil, local health authorities have observed an increase in Guillain-Barré syndrome which coincided with Zika virus infections in the general public, as well as an increase in babies born with microcephaly in northeast Brazil. Agencies investigating the Zika outbreaks are finding an increasing body of evidence about the link between Zika virus and microcephaly. However, more investigation is needed to better understand the relationship between microcephaly in babies and the Zika virus. Other potential causes are also being investigated.

Transmission

Zika virus is transmitted to people through the bite of an infected mosquito from theAedes genus, mainly Aedes aegypti in tropical regions. This is the same mosquito that transmits dengue, chikungunya and yellow fever. However, sexual transmission of Zika virus has been described in 2 cases, and the presence of the Zika virus in semen in 1 additional case.

Zika virus disease outbreaks were reported for the first time from the Pacific in 2007 and 2013 (Yap and French Polynesia, respectively), and in 2015 from the Americas (Brazil and Colombia) and Africa (Cabo Verde). In addition, more than 13 countries in the Americas have reported sporadic Zika virus infections indicating rapid geographic expansion of Zika virus.

Diagnosis

Infection with Zika virus may be suspected based on symptoms and recent history (e.g. residence or travel to an area where Zika virus is known to be present). Zika virus diagnosis can only be confirmed by laboratory testing for the presence of Zika virus RNA in the blood or other body fluids, such as urine or saliva.

Prevention

Mosquitoes and their breeding sites pose a significant risk factor for Zika virus infection. Prevention and control relies on reducing mosquitoes through source reduction (removal and modification of breeding sites) and reducing contact between mosquitoes and people.

This can be done by using insect repellent regularly; wearing clothes (preferably light-coloured) that cover as much of the body as possible; using physical barriers such as window screens, closed doors and windows; and if needed, additional personal protection, such as sleeping under mosquito nets during the day. It is extremely important to empty, clean or cover containers regularly that can store water, such as buckets, drums, pots etc. Other mosquito breeding sites should be cleaned or removed including flower pots, used tyres and roof gutters. Communities must support the efforts of the local government to reduce the density of mosquitoes in their locality.

Repellents should contain DEET (N, N-diethyl-3-methylbenzamide), IR3535 (3-[N-acetyl-N-butyl]-aminopropionic acid ethyl ester) or icaridin (1-piperidinecarboxylic acid, 2-(2-hydroxyethyl)-1-methylpropylester). Product label instructions should be strictly followed. Special attention and help should be given to those who may not be able to protect themselves adequately, such as young children, the sick or elderly.

During outbreaks, health authorities may advise that spraying of insecticides be carried out. Insecticides recommended by the WHO Pesticide Evaluation Scheme may also be used as larvicides to treat relatively large water containers.

Travellers should take the basic precautions described above to protect themselves from mosquito bites.

Zika in America

Treatment

Zika virus disease is usually relatively mild and requires no specific treatment. People sick with Zika virus should get plenty of rest, drink enough fluids, and treat pain and fever with common medicines. If symptoms worsen, they should seek medical care and advice. There is currently no vaccine available.

WHO response

WHO is supporting countries to control Zika virus disease through:

• Define and prioritize research into Zika virus disease by convening experts and partners.
• Enhance surveillance of Zika virus and potential complications.
• Strengthen capacity in risk communication to help countries meet their commitments under the International Health Regulations.
• Provide training on clinical management, diagnosis and vector control including through a number of WHO Collaborating Centres.
• Strengthen the capacity of laboratories to detect the virus.
• Support health authorities to implement vector control strategies aimed at reducing Aedes mosquito populations such as providing larvicide to treat still water sites that cannot be treated in other ways, such as cleaning, emptying, and covering them.
• Prepare recommendations for clinical care and follow-up of people with Zika virus, in collaboration with experts and other health agencies.

References :-
1) http://www.who.int/mediacentre/factsheets/zika/en/
2) http://www.cdc.gov/zika/
3) http://ecdc.europa.eu/en/healthtopics/zika_virus_infection/Pages/index.aspx
4) http://www.webmd.com/a-to-z-guides/zika-virus-symptoms-prevention

What is biology?

Post by: Ananya Bhardwaj

The study of living organisms, divided into many specialized fields that cover their morphology, physiology, anatomy, behavior, origin, and distribution.