Viruses Flashcards
What are viruses made of?
Viruses are composed of a core of nucleic acid surrounded by a proton donor
Where do viruses grow?
Because they are not made of cells, they do not have the cell machinery for their own metabolism, so they only grow in living tissue.
What can viruses be considered outside of living cells?
Where they exist outside of living cells, they may be considered non-living chemicals, since they do not display any of the characteristics of life.
What can viruses do once inside a living cell?
Once they are inside a living cell they can replicate with the help of the host cell and so are clearly alive.
Do viruses have features of living or non-living material?
So, viruses have features of both living and non-living material.
What are viruses called because since they can only multiply inside living cells?
Since they can only multiply inside living cells, they are called obligate parasites
What can viruses do as parasites?
As parasites they cause many diseases in humans, domestic animals and crop plants.
What are viruses called because since they can only multiply inside living cells?
Since they can only multiply inside living cells, they are called obligate parasites
What does being obligate parasites mean in terms of agar?
This means that they cannot be grown on agar like bacteria or fungi
What does being obligate parasites mean to do with antibiotics?
It is also the reason why antibiotics do not work against them, as there is no cell machinery for the antibiotic to damage.
What is one way of recognising and classifying different viruses?
Different kinds of viruses have different shapes and this is one way of recognising and classifying them.
How can we only see viruses because they are so small?
Because viruses are so small, we can only see them with an electron microscope.
How many viruses could fit side by side on the tip of your pen?
10,000 viruses could fit side by side on the tip of your pen.
Draw virus replication.
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What are the disadvantages of viruses?
Diseases of humans, plants and animals
What are common human diseases?
Measles, Mumps, Rubella, Cold, Warts
How do plant diseases gain entry to a plant?
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What are examples of plant diseases?
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What are examples of animal diseases?
Foot and mouth, SARS (Sudden Acute Respiratory Syndrome) and Rabies
What are the advantages of viruses?
Genetic engineering, where they are used inject a gene into target cells.
Mosaic patterns give new variety to garden plants.
What is immunity?
Immunity is the ability of an organism to resist infection.
What are pathogens?
Pathogens are micro-organisms [microbes] that cause disease.
What is the human body designed to do in terms of foreign cells or invaders?
The human body is designed to protect itself from foreign cells or invaders, and we have two lines of defence - general and specific.
What does our general defence system consist of?
Our general defence system consists of skin, mucous membranes, platelets and white blood cells.