about mutation and genotype

1. 我想問如果parent其中一個sex cell mutate左, 其offspring的genotype係唔係會因此而改變? 咁parent的o個個cell的genotype又會唔會變呢???

2. 如果parent其中一個body cell mutate左, 其offspring的genotype係唔係會因此而改變? 咁parent的o個個cell的genotype又會唔會變呢???

3.the table below which shows the phenotypes and genotypes of two mice (X and Y).
A is the gene for black coat and A ‘ is the gene for white coat.

Mouse X Mouse YPhenotype black coat white coat
Genotype AA AA'

If A’ resulted from a mutation of gene A, the mutation is most likely to have taken place inA. the ovary of mouse Y.
B. the ovary of the parent of mouse Y.C. the skin of mouse Y.D. the skin of the parent of mouse Y.
個ans係b, 但點解唔係a???