"Virus" PPT

Description

"Virus" PPT

A virus is a biological entity whose genome is a nucleic acid molecule (DNA or RNA) that can replicate in living cells using the cell's synthetic system and synthesize special particles that can transfer the viral genome to other cells.

discovery of virus

During the 18th Egyptian Dynasty (1500 BC), the relief carving showed a priest with a shrunken leg - polio.

The ancient Greek philosopher Aristotle described the symptoms of rabies as early as the fourth century BC.

Smallpox was recorded in my country and India in the 2nd and 3rd centuries BC.

Tulip fever in Western Europe in the 17th century - mosaic virus caused the petals to become beautifully variegated.

Since then, many scholars have successively discovered various plant viruses, animal viruses and bacterial viruses (phages).

Characteristics of viruses

The shape is so tiny that it can only be observed under an electron microscope.

There is no cellular structure.

Its main components are nucleic acids and proteins.

Each virus contains only one type of nucleic acid (DNA or RNA).

There is neither energy-producing enzyme system nor protein synthesis system.

Proliferation occurs through the replication of nucleic acids and the assembly of nucleic acid proteins with the assistance of host cells.

Operate as an obligate parasite within the cells of the host.

Under in vitro conditions, it can exist in the state of inanimate chemical macromolecules and can form crystals.

Not sensitive to general antibiotics, but sensitive to interferon.

Virus size and shape

Size: The size of the virus is commonly measured in nanometers (nm, 10-9). The size of the virus ranges from 10 to 300nm, usually around 100nm.

Most viruses can pass through bacterial filters.

An electron microscope is required to observe its specific shape and size.

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"Virus" PPT courseware download:

Download the first part of the "Virus" PPT courseware: The common viral disease mumps (epidemic parotitis, mumps) is an acute respiratory infectious disease caused by the mumps virus invading the parotid gland. It is a common respiratory infectious disease among children and adolescents, and adults. .

"Virus" PPT download:

"Virus" PPT Download Part One: Microorganisms More than 99% of the organisms on the earth are invisible to the naked eye. These organisms form a crowded and chaotic world of microorganisms. Small life forms are called microorganisms. Viruses Bacteria Fungi Protozoa Viruses are...

"Virus" PPT courseware 7:

"Virus" PPT Courseware 7 Learning Objectives 1. Describe the main characteristics of viruses. 2. Use information to understand the relationship between viruses and humans. 3. Pay attention to virus-related diseases and agree that the use of viruses can benefit mankind. Duxue P89-92: 1. Who discovered the virus? Virus..

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Update Time: 2024-12-02

This template belongs to science courseware Qingdao Edition Fifth Grade Science Volume 1 industry PPT template

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