Superantigens produce a harmful immune response because
A) they activate too many T cells, causing excessive inflammation and cell damage.
B) they initiate a type I allergic response resulting in excessive inflammation.
C) too many phagocytes are activated and destroy host tissue.
D) a strong immune response is necessary to protect the host from the pathogen.
Answer: A
You might also like to view...
Which of the following prevents some bacteria from adhering to mucosal surfaces?
A. IgD B. IgE C. IgM D. IgA
Answer the following statements true (T) or false (F)
1.Mammals that lay eggs are marsupials.
2.Main animal groups are noted at the right. Names diverging at each node are morphological or body form names. Note that the animal traits key to distinguishing the groups and body forms are not shown.
3.The vegetative parts of plants are those involved in reproduction.
4.The aboveground portion of the plant is called the shoot.
5.Grasses and other monocots usually have fibrous root systems.
The breeder's equation shows that the rate of evolution depends on the strength of heritability, and the strength of directional selection. Evolution can be expected when:
A. S is negative, and h^2 is 1 B. S is > 0 and h^2 < 0 C. S is equal to 0, and h^2 is > 0 D. S is not equal to 0, and h^2 is 0
What is a homeobox?
A. An enhancer region needed for expression of a homeotic gene B. The portion of the promoter to which a homeoprotein binds to activate transcription of genes important for development C. A sequence within a homeotic gene that encodes the DNA-binding portion of a transcription factor D. A cluster of homeotic genes E. None of the answers are correct.