Take a close look at the chromosomes in division 1, when homologous chromosomes come together and form tetrads. the arms of the non-sister chromatids have wound around each other and exchanged segments of chromosomes. this is called and contributes to genetic variation. a) segregation b) crossing over c) nondisjunction d) allelic mixing

Which plate boundary causes plates to collide forming mountain ranges, volcanoes, and island arcs? give an example of this type of plate boundary. 2. at which plate boundary do rifts and mid-oceans ridges form? give an example of this type of plate boundary. 3. at which plate boundary do plates slide past each other while moving in opposite directions? give an example of this type of boundary.

Which of the following describes research that would be considered basic science? a. a farmer is trying to improve his crop yields by using a new kind of fertilizer. b. a college students is curious about the growth of desert pants in the presence of excess amounts of water. c. government officials are trying to prevent the spread of new strain of influenza virus. d. a doctor is trying to determine why a patient is feeling tried and sick. b.a college students is curious about the growth of desert pants in the presence of excess amount of water

Attached earlobes are a reccesive trait in humans. in the tree below, people with attached earlobes are shaded in. which best describes labeled x in the tree? a: a female with one recessive allele b: a female with no recessive allelesc: a male with no recessive allelesd: a male with one recessive allele