ASAP! Please? Since monotremes can lay eggs, why aren't they classified as birds?
-- Explanation NOT multiple choice question --

What is thought to have caused the mass extinction at the end of the cretaceous period?

The first generation of offspring from the cross of two parents is called the a.f1 generation b.f2 generation c.short generation d.p generation

Which of these is true of the cytoplasm of an unfertilized egg? a. it is an unevenly distributed mixture of mrna, proteins, organelles, and other substances. b. it does not contain substances that are important in directing development. c. these substances are supplied by the sperm. d. it does not contain substances that are important in directing development. e. development is directed solely by the surrounding cells. f. it is a homogeneous mixture of mrna, proteins, organelles, and other substances. g. it does not contain substances that are important in directing development. h. these substances are produced by the dna of the fertilized zygote.