A patient is seen in the clinic with severe bowing of the legs, and is found to have a 46, XY karyotype in spite of female appearing external genitalia. Which of the following is the most likely reason for these syndromic symptoms.

In human infants with defects of the 21-hydroxylase enzyme (congenital adrenal hyperplasia), they have high levels of _________ and this results in defects of the ___________ of 46, XX infants. Fill in the blanks with the BEST answer.

Multiple dropdowns. Choose the best answer for each. Melanocytes derive from  [Answer1]  and migrate  [Answer2].  

Hormones regulate the development of the male reproductive tract. Which hormone must be present during embryogenesis in order for the vas deferens, epididymis and seminal vesicles to form?

What conclusion does this image support?    

SOX9 is necessary for testis development. Which of the following factors are necessary for activation of its expression embryonically?

During embryonic development the vessels of the vasculature must correctly connect. Which of the following molecules mediate this event?  

Cardiac neural crest cells contribute to septa that separate the trunk arterioles into the pulmonary artery and aorta, such that lack of these neural crest cells can lead to __________. Complete the sentence with the best answer below.

All heart cells derive from a common progenitor referred to as the ___________. Fill in the blank with the best answer.

The green structure in the image represents a developing pharyngeal arch. Considering its location and the adult structures that arise from it, which pharyngeal arch is shown below in green?