Sister chromatids of a pair of homologous chromosomes form tetrads, and crossing-over (exchange of genetic information between regions of non-sister chromatids in the tetrad) occurs during which phase

Which of the following does not describe a physical property of iron? a iron is silvery-white or gray in color. b iron has a boiling point of about 3,000°c. c iron is a magnetic element . d iron and sulfur react to form iron sulfide.

The cluster of developing cells from conception until birth is called an

Food webs - transferring energy and matter from one level to another. here you see four food webs. one or more are incorrect. which food web(s) show the correct sequence of organisms, from start to top level consumer? a) a b) d c) c d) a and d