Someone please help me with biology ASAP.

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

Explain how negative feedback caused the changes in plasma glucagon concentration observed during the experiment.

Mendel used over 28,000 pea plants in his experiment. how does this large sample size make his results more reliable? (i'm not sure about this one)