Question

two bird populations live on opposite sides of a mountain range. one particularly harsh winter, the blue birds on the north side of the mountain immigrated to the other side of the mountain. this blue population of birds began mating with the existing population of birds which were red in color. if the red birds are homozygous recessive, which statement is false concerning these populations of birds? a the red bird population will most likely dwindle. b the alleles for color are cc, cc, and cc. all red birds are cc and blue birds are cc or cc. c the gene pools of these birds will be combined, leading to a marked change in allele frequencies d the immigration of birds over the mountain boundary will most likely lead to speciation of these birds.

Explanation:

• Option A: When blue birds (likely dominant allele carriers) mate with red (recessive, cc) birds, red population may decrease as offspring could have dominant alleles, so A is true.
• Option B: If red is homozygous recessive (cc), blue could be CC (homozygous dominant) or Cc (heterozygous), so allele combinations make sense, B is true.
• Option C: Immigration and mating combine gene pools, changing allele frequencies (e.g., introducing C alleles to red population), C is true.
• Option D: Speciation requires reproductive isolation. Here, birds are mating, so gene flow occurs, reducing chances of speciation. So D is false.

Answer:

D. The immigration of birds over the mountain boundary will most likely lead to speciation of these birds.