Examine the Image Below

question 59

Essay

Examine the image below.Why does a comet usually have two tails,one that is straight and one that is curved? What materials compose each tail,and why do they have different shapes?

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Definitions:

Chromosome

One of the 46 molecules of DNA (in 23 pairs) that virtually every cell of the human body contains and that, together, contain all of the genes. Other species have more or fewer chromosomes.

Involuntary Response

A reflex or action that occurs automatically without conscious thought, often as a result of a stimulus.

Allele

A variation that makes a gene different in some way from other genes for the same characteristics. Many genes never vary; others have several possible alleles.