Genes a and b are 21 m. u. apart when mapped in highly inbred strain 1 of corn and 21 m. u. apart when mapped in highly inbred strain 2. But when the distance is mapped by testcrossing the F1 progeny of a cross between strains 1 and 2, the two genes are only 1.5 m. u. apart. What arrangement of genes a and b and any potential rearrangement breakpoints could explain these results

you are the source of the heat energy. you can minimize the heat energy by selecting the appropriate clothes to wear.

i think the answer is

mass

the correct answer is option d.

an appositive is a noun, noun phrase or noun clause which follows another noun or noun phrase in order to describe it or name it another way. they are usually used between commas, brackets or dashes.

the example sentence with the correct use of commas is the following:

her uncle, the man over there in the red shirt, owns the hardware store in town.