GCSE Biology - What Is a Virus? - Examples of Viral Disease (HIV, Measles & TMV) #36
Summary
TLDRThis video delves into the nature of viruses, which are non-cellular organisms that can only replicate by hijacking host cells. It explores three viral diseases: measles, a highly contagious disease with a characteristic rash and fever, now rare in the UK due to widespread vaccination; HIV, which weakens the immune system and can progress to AIDS, but is manageable with antiretroviral drugs; and the tobacco mosaic virus, which affects plants like tobacco, causing a mosaic pattern on leaves and hindering photosynthesis.
Takeaways
- 🦠 Viruses are not cells and are not considered living organisms, yet they are classified as organisms.
- 🔍 Viruses are approximately 10,000 times smaller than animal cells and cannot reproduce on their own.
- 🌀 Once inside a host cell, viruses can hijack the cell's machinery to replicate and produce many copies of themselves.
- 💥 The process of viral replication and cell bursting can lead to damage in our bodies, causing illness.
- 📣 Measles is a viral disease spread through droplets from coughs or sneezes, causing a rash and fever.
- 💉 Measles is rare in the UK due to widespread vaccination, but it can be serious and sometimes fatal.
- 🚫 HIV is transmitted through sexual contact and sharing of bodily fluids like blood, and it attacks the immune system.
- 🤒 Initial HIV infection might present flu-like symptoms, but it can progress to severely weaken the immune system, leading to AIDS.
- 💊 Antiretroviral drugs can prevent HIV replication, allowing those with access to treatment to live normal lives.
- 🌿 The tobacco mosaic virus (TMV) affects plants, causing a mosaic pattern on leaves and disrupting photosynthesis.
Q & A
What is a virus and how does it differ from living cells?
-A virus is not a cell and is not considered living. It is an organism that is about 10,000 times smaller than animal cells and cannot reproduce by itself. It requires the machinery of a host cell to replicate.
How do viruses cause illness in the body?
-Viruses cause illness by colonizing and then bursting host cells, which damages the body's tissues and can lead to various symptoms depending on the type of virus.
What are the three viral diseases discussed in the video?
-The three viral diseases discussed in the video are measles, HIV, and tobacco mosaic virus.
How is the measles virus typically transmitted?
-The measles virus is transmitted through droplets when an infected person coughs or sneezes.
What are the common symptoms of measles?
-Common symptoms of measles include a red rash across most of the body and a fever, which is characterized by a high temperature and general malaise.
Why is measles rare in the UK?
-Measles is rare in the UK because nearly everyone is vaccinated against it.
How can HIV be transmitted and what does it stand for?
-HIV can be transmitted through sexual contact, sharing needles, or exchanging bodily fluids like blood. HIV stands for human immunodeficiency virus, indicating it affects humans and causes an inadequate immune system.
What is the difference between HIV and AIDS?
-HIV is the virus itself, while AIDS (Acquired Immunodeficiency Syndrome) is the advanced stage of the HIV infection where the immune system is severely compromised and the person is susceptible to unusual infections and cancers.
What are antiretroviral drugs and how do they help in treating HIV?
-Antiretroviral drugs are medications that prevent the HIV virus from replicating within the body. If taken early in the disease, they can help people with HIV live normal lives.
What is the tobacco mosaic virus and how does it affect plants?
-The tobacco mosaic virus (TMV) is a virus that affects certain plant species like tobacco and tomato plants. It causes discolored patches on leaves, disrupting photosynthesis and thus hindering the plant's ability to produce enough sugars for proper growth.
What is the significance of the term 'mosaic' in the context of the tobacco mosaic virus?
-The term 'mosaic' refers to the discolored patches that the virus causes on the leaves, forming a mosaic pattern, which disrupts the plant's photosynthesis and growth.
Outlines
🦠 Understanding Viruses and Their Impact
This paragraph introduces viruses, explaining that they are not cells and not living organisms but are still considered organisms. Viruses are very small, about 10,000 times smaller than animal cells, and cannot reproduce on their own. However, once inside a host cell, they can use the cell's machinery to replicate. This replication and subsequent bursting of cells can damage the body and cause illness. The paragraph also sets the stage for discussing three specific viral diseases: measles, HIV, and the tobacco mosaic virus.
Mindmap
Keywords
💡Virus
💡Measles
💡HIV
💡AIDS
💡Tobacco Mosaic Virus (TMV)
💡Droplets
💡Replication
💡Colonizing
💡Bursting
💡Vaccination
💡Antiretroviral drugs
Highlights
Viruses are not cells and not living, yet considered organisms.
Viruses are about 10,000 times smaller than animal cells.
Viruses cannot reproduce by themselves but can use host cell machinery to replicate.
Viral replication can damage host cells leading to illness.
Measles virus spreads through droplets from coughs or sneezes.
Measles causes a red rash and fever.
Measles is rare in the UK due to widespread vaccination.
HIV can be transmitted through sexual contact and sharing needles.
HIV stands for human immunodeficiency virus, affecting the immune system.
Initial HIV infection may present flu-like symptoms.
HIV progressively weakens the immune system, leading to AIDS if untreated.
AIDS is a syndrome where the immune system cannot cope with infections and cancers.
Antiretroviral drugs can prevent HIV replication, allowing for normal life expectancy.
Tobacco mosaic virus (TMV) affects certain plant species, causing discolored patches.
TMV disrupts photosynthesis, hindering plant growth and sugar production.
The video concludes with an invitation for viewers to like and return for more content.
Transcripts
in this video we're gonna take a look at
what viruses are and at three of the
disease is the leading cause now viruses
are quite hard to explain
they aren't cells and they're not living
but we only still consider them to be
organisms there are about 10,000 times
smaller than animal cells and they can't
reproduce by themselves however what
they get inside another organism cell
they can use that cells own machinery to
make loads of copies of themselves
and then when the time is right it can
burst the cell and all of those new
viruses will have to find new cells to
take over
this process of colonizing and then
bursting our cells is obviously going to
damage our bodies and that's one of the
main reasons that viruses make us feel
ill
the three examples of viral disease that
we're going to look at are measles HIV
and tobacco mosaic virus
the measles virus is spread by droplets
when an infected person coughs or
sneezes it generally causes people to
develop a red rash across most of their
body and the fever which is where you
get a really high temperature and
generally feel unwell although it can be
really serious and sometimes even fatal
it's luckily really rare in the UK as
nearly everyone is vaccinated against
her when a young
a GRB on the other hand can be spread by
sexual contact such as unprotected sex
all by exchanging bodily fluids such as
the blood for example when people share
needles
HIV stands for human immunodeficiency
virus which tells us that affects humans
and it causes a deficient or inadequate
immune system
and it's a bit weird but when you use
the term HIV you're referring to the
actual virus not to disease
when somebody first catches HIV it might
get flu-like symptoms for a few weeks so
fever tiredness and aches but then I'll
start to feel better and think they're
everything's fine
however inside their body the parties
are doing more and more damage to their
immune system and at some point the
immune system becomes so weak that they
start to catch unusual infections and
sometimes even get cancers
at this point we say that the person has
developed AIDS which is classed as a
disease or syndrome in which the
person's immune system can't cope
anymore
this used to be the end of the story as
people would die of random infections or
cancer now they're with a group of
medications called antiretroviral drugs
which prevent the virus from replicating
within our bodies so as long as people
have access to these medications early
on in their disease that they can go on
to live normal lives
the last viral disease we're going to
cover is caused by tobacco mosaic virus
or tmv this virus affects plants instead
but only certain species such as tobacco
and martyr plants
the reason is called mosaic is because
it dis colours patches on the leaves
causing a mosaic pattern to form the
problem is a photosynthesis can take
place and it's discolored patches and so
overall the plant won't be able to
produce enough sugars for proper growth
and that's all for now if you enjoyed it
then please do give us a like and we'll
see you next time
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