Our nostrils has hair and mucous. What is the need to have them in our nasal cavity?

Round seeds and yellow seed color are dominant to wrinkled seeds and green seed color. which punnett square represents the correct way to set up the cross rryy  ´  rryy? 

Pentane with molecular formula c5h12, exists in three isomeric forms. one shows linear carbon chains, another has one -ch3 groups present on the third carbon atom, and the third has two -ch3 groups present on the second carbon atom. what types of isomers are these? a. geometric isomers b. structural isomers c. halotropic isomers

Which animal is a producer in this ecosystem