Which happens during crossing over? Two sex cells join together and combine DNA.
Genes are exchanged between two alleles.
Genes are exchanged between two egg cells.
Chromosomes line up randomly during metaphase I.

Nonmetal halogen family atmoic mass 35

Ted and emily played a mixed doubles tennis match against jack and brenda. in the second match. ted and brenda played against jack and emily. which type of chemical reaction does the situation demonstrate?

Which sentence about particles in matter is true? a. atoms are present in solids and liquids but not in gases. b. the particles of matter are in constant motion. c. the same kinds of atoms are found in different elements. d. when a solid changes to a liquid, the sizes of the particles change.