A genetic trait might be caused by incomplete dominance if: A. red-, white-, and pink-flowered plants grow from the seeds of a
blue-flowered plant.
B. pinks, white, and red-flowered plants grow from the seeds of a
pink-flowered plant.
C. two plants with red flowers are the parents of plants with either
red flowers or white flowers.
O D. two plants with red-and-white flowers are the parents of plants
with either white flowers or pink flowers.

try using substitution:

x + y - 6 = x - y. (i'm not giving you the exact answer). since 0 = x - y, then sub 0 in the equation with x - y. combine your like terms, and then use inverse operations, and you'll have your answer.

: -)

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.