BACTERIA, VIRUSES & OTHER PATHOGENS

Most of the minerals within an ecosystem are recycled and returned to the environment by the direct activities of organisms known as

• producers
• secondary consumers
• decomposers
• primary consumers

Tags

NGSS.MS-LS2-3

Base your answer on the viral activity which is represented in the diagram below.
What does invading the host cell enable the virus to do?

• increase its size
• synthesize needed oxygen
• obtain nutrients
• reproduce

People with AIDS are unable to fight multiple infections because the virus that causes AIDS

• weakens their immune systems
• produces antibodies in their blood
•  attacks muscle tissue
• kills pathogens

A vaccine for the viral disease known as chicken pox would contain

• a large amount of live virus
• a dead or weakened form of the pathogen
• several different antibiotics
• a small number of white blood cells

The diagram represents a protist.
The protist is taking in food particles by the process of

• hydrolysis
• ingestion
• egestion
• cyclosis

Atmospheric nitrogen can only be used by most living things after it has been

•  converted to nitrates with the help of nitrogen-fixing bacteria
• taken in by plants through the lenticels
• converted to ammonia by bacteria of decay
• combined with carbon dioxide to form protein

Tags

NGSS.MS-LS2-3

Prions are proteins that act as an infectious agent. They cause a variety of diseases, including “Mad Cow” disease. Prions cannot produce more prions on their own, but cause the host organism to replicate more prions. Most scientists do not consider prions to be alive. A valid reason for accepting that prions are nonliving things is that

• no living thing can cause a disease
• proteins are inorganic molecules
• prions contain all of the material needed to reproduce
•  prions cannot carry out reproduction independently

Which statement best describes why pathogens are harmful?

• All of the cells of an organism infected by pathogens become pathogens.
• Pathogens cannot be controlled once they enter the cells of an organism.
• Pathogens produce antibodies that will kill the host organism.
• Pathogens can interfere with normal life functions.