Diversity of Life 1.3
Learning Target: Viruses are not alive but affect living things.
Review:
Most organisms are made of a single cell.
Living things share common characteristics.
Viruses are not living things.
Learning Target: Viruses are not alive but affect living things.
Review:
Most organisms are made of a single cell.
Living things share common characteristics.
Viruses are not living things.
Part 1
What is a virus? How does it compare in size to a bacteria cell?
What is a virus? How does it compare in size to a bacteria cell?
Part 2
Scientists have learned much about viruses, and can even make images of them with specialized microscopes. Viruses consist of genetic material contained inside a protective protein coat called a capsid. The protein coat may be a simple tube, such as the coat of an Ebola virus, or have many layers, such as the smallpox virus.
Viruses come in many shapes and sizes, but all viruses consist of a capsid and genetic material. Viruses are able to use living cells to get their DNA copied and so can produce new viruses, a characteristic that makes them similar to living things. Also the protein coat is similar to a cell's outer membrane. But viruses do not grow, and viruses do not respond to changes in their environment. Therefore, viruses are not living organisms.
List 2 things viruses have in common with living things.
List 2 things viruses do not have in common with living things.
Scientists have learned much about viruses, and can even make images of them with specialized microscopes. Viruses consist of genetic material contained inside a protective protein coat called a capsid. The protein coat may be a simple tube, such as the coat of an Ebola virus, or have many layers, such as the smallpox virus.
Viruses come in many shapes and sizes, but all viruses consist of a capsid and genetic material. Viruses are able to use living cells to get their DNA copied and so can produce new viruses, a characteristic that makes them similar to living things. Also the protein coat is similar to a cell's outer membrane. But viruses do not grow, and viruses do not respond to changes in their environment. Therefore, viruses are not living organisms.
List 2 things viruses have in common with living things.
List 2 things viruses do not have in common with living things.
Part 3 parts of a virus
Part 4
Viruses cannot reproduce by themselves. However, viruses use materails within living cells tomake copies of themselves. The cells that viruses infect in order to make copies are called Host cells. Despite their tiny size, viruses have the ability to cause a lot of damage to cells of other organisms. One of the best studied viruses infects bacteria cells. The steps that the virus goes through to multiply are drawn below.
Viruses cannot reproduce by themselves. However, viruses use materails within living cells tomake copies of themselves. The cells that viruses infect in order to make copies are called Host cells. Despite their tiny size, viruses have the ability to cause a lot of damage to cells of other organisms. One of the best studied viruses infects bacteria cells. The steps that the virus goes through to multiply are drawn below.
Attachment: The virus attaches to the surface of a bacterium.
Injection: The virus injects its DNA into the bacterium.
Production: Using the same machinery used by the host cell for copying its own DNA, the host cell makes copies of the viral DNA.
Assembly: The viral DNA forces the infected cell to assemble new viruses from the parts it has created.
Release: The cell bursts open, releasing 100 or more new viruses.
Injection: The virus injects its DNA into the bacterium.
Production: Using the same machinery used by the host cell for copying its own DNA, the host cell makes copies of the viral DNA.
Assembly: The viral DNA forces the infected cell to assemble new viruses from the parts it has created.
Release: The cell bursts open, releasing 100 or more new viruses.
Part 5
Viruses may harm host cells an and can cause major death and damage. Viruses that have caused widespread death are polio, smallpox, and AIDS. About 25 million people died of influenza in an outbreak that occurred just after World War 1. Plant viruses can stunt plant growth and kill plants. When plant viruses invade crop plants, they can cause much economic damage and decrease food production.
Viruses may harm host cells an and can cause major death and damage. Viruses that have caused widespread death are polio, smallpox, and AIDS. About 25 million people died of influenza in an outbreak that occurred just after World War 1. Plant viruses can stunt plant growth and kill plants. When plant viruses invade crop plants, they can cause much economic damage and decrease food production.