What is the job of the arrector pili muscle how is this related to the phenomenon called goosebumps?

How does the author's purpose in this passage differ from an author writing about her personal struggle living with asthma?

What are the formed elements (cell or parts of cell) in blood and what are their functions ?

Amale bird-of-paradise uses a dance to attract mates in which it flaps its tail feathers on the ground and jumps around a potential female mate. a different male bird-of-paradise does a similar dance but it jumps around the female in the opposite direction. the female bird is only attracted to one style of dance, in one direction.