After chromosomes are formed, during which phase of mitosis do the chromosomes attach to the spindle fibers by their centromeres?

Spindle fibers are attached to their centromeres in metaphase.

Chromosomes are formed during the prophase of mitosis, in this phase nucleus disappears, formation of spindle fiber takes place and chromosomes are formed from the condensed DNA which is then followed by the alignment of spindle fibers on the equator of the cell to get attached with their centromeres, alignment followed by the attachment of spindle fibers to their centromeres occurs in metaphase.  

ans.

gregor john mendel is known for study of inheritance in pea plants. he used garden pea plant for his study, having alternative traits for various characters. he performed cross-breeding in pea plants to check how characters are transmitted between parents to offspring, such as cross between pure tall and pure dwarf plant. mendel studied the inheritance patterns in pea plants for various generations.

thus, the correct answer includes options and f).