Suppose that in unicorns, two autosomal loci interact to determine the type of tail. One locus controls whether a tail is present at all. The allele for a tail, T, is dominant over the allele for no tail, t. If a unicorn has a tail, then alleles with an unknown dominance relationship at a second locus determine whether the tail is curly or straight. Define the alleles for tail texture as US for a straight tail and UC for a curly tail.

Explanation:

As you can see in the picture below, this is a dihybrid cross with a twist.

We can accomplish that mutually parentages are heterozygotes for both characters because the genotypes are  

9 unicorns with curly tails (shown in green)

3 with straight tails (shown in red)

3  curly tales trait carriers with no tail (shown in dark blue)

1  straight tail trait carriers with no tail ( shown in light blue)

If this was an ordinary case of the dihybrid cross, we would get a 9:3:3:1 phenotype ratio.

However, since the first trait, the presence of the tail, is affecting the other trait, the trait texture, the ratio is altered.

of the offspring (genotypes tt C_   and tt SS) has no tail, therefore we cannot observe the texture of the tail (some of the tailless individuals have Curly alleles -blue squares marked with green, some of them have Straight alleles -blue square marked with red ).

Therefore, the altered ratio is   curly tails, straight tales, tailless

"menstrual cycle is a complex cycle that consists of several processes. order of occurrence of steps in menstrual cycle are as follows:

1. high progesterone levels maintain the endometrium lining of the uterus.

2. endometrium lining breaks down and low levels of estrogen stimulate the pituitary to release fsh and lh.

3. fsh and lh stimulates the follicles to develop and the oocyte to produce estrogen.

4. rising estrogen levels suppress fsh production and development of other follicles.

5. a spike in lh causes follicle to rupture.

6. a breakdown of corpus luteum causes progesterone level to drop."