If b is the trait for brown eyes and b is the trait for blue, and a homozygous dominant dad and a homozygous recessive mom have off-spring. how many of the f1 generation will be bb?

Zero of the offspring will be bb.  Since each offspring receives one allele from each parent, all will receive a B from Dad and a b from Mom, making all of the offspring heterozygous (Bb) and brown-eyed.

halogen, any of the six nonmetallic elements that constitute group 17 (group viia) of the periodic table. the halogen elements are fluorine (f), chlorine (cl), bromine (br), iodine (i), astatine (at), and tennessine (ts).

a. by using fur or clothes to trap heat energy near the body