A salamander population was divided when a highway was built, cutting off one end of the stream from the pond it had connected to. Over many generations, the salamanders evolved into two completely different species. What is the best explanation for this?
A. fish ate all the slower salamanders.
B. One salamander outcompeted the other for food and resources
C. Humans brought the second salamander over from Europe and started breeding it in the pond.
D. The isolation of each population (along with random mutation) over time made it impossible for the two populations to interbreed with each
other

Select the correct answer. tay-sachs disease is caused by a mutation in the hexa gene located on chromosome 15. tay-sachs follows an autosomal recessive pattern of inheritance. with the of the diagram, identify which of the offspring will be an unaffected carrier. a diagram showing the genes of parents who are carriers of tay-sachs disease a. a, b, and c b. b and c c. a and d d. a e. d

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.

Ascientist wanted to formulate a pill to attack a specific type of bacteria that infects the throat. which biological component would be best to use as a model for the pill's function? bacteriocytes phagocytes complement antibodies