What Is a Planetary Nebula

question 3

Multiple Choice

What is a planetary nebula?

• A)the bipolar jets ejected by a T Tauri variable
• B)a planet surrounded by a glowing shell of gas
• C)the disk of gas and dust surrounding a young star that will soon form a solar system
• D)the ejected envelope, often bipolar, of a red giant surrounding a stellar core remnant
• E)a type of young, medium mass star

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Definitions:

Dendritic Cell

A type of immune cell that presents antigens to T cells, initiating an adaptive immune response; pivotal in mediating immunity and tolerance.

Autoimmune Disease

A condition where the body's immune system mistakenly attacks its own cells, tissues, or organs.

Immune Response

The body's defensive reaction to foreign substances or pathogens.

Human Immunodeficiency Virus (HIV)

A virus that attacks the immune system, leading to acquired immunodeficiency syndrome (AIDS) if not treated.