Endocrine function

What is the skill that Daulerio says he’s really good at?

Melanin synthesis (which produces pigment) in the eye is determined by 2 genes. The OCA2 gene controls melanin synthesis; MM or Mm = brown color; mm = blue color The HERC2 gene controls (“switches on”) the OCA2 gene; HH or Hh = brown color; hh = blue color. Therefore, a homozygous recessive genotype for either gene (i.e., hh or mm) results in blue eyes. Two parents, one with blue eyes and one with brown eyes, have the following genotypes: hhmm and HhMm . What is the probability that they will have a blue-eyed child?  (Use the forked-line method or do a Punnet square).

Breast cancer shows autosomal dominant inheritance with incomplete penetrance among females who inherit one affected BRCA2 allele. In a study 30 of 50 females who inherited a BRCA2 mutation developed breast cancer by 80 years old. What is the penetrance of breast cancer in this population of females?

Spinal muscular atrophy (SMA) type I shows autosomal recessive inheritance. Assuming complete penetrance, if two heterozygous individuals have a child, what is the probability the child will be affected with SMA type I?  

Blood type is determined by two genes.  At least 1 dominant H gene allele is needed to build the H antigen: HH or Hh = H antigen, i.e., normal; hh = no H antigen, i.e., Bombay If an individual has the H antigen (i.e., is not Bombay), the I gene then determines blood type O, blood type A, blood type B or blood type AB (IAIA or IAi = blood type A; IBIB or IBi= blood type B; IAIB = blood type AB; ii = blood type O).                             H gene                                                                I gene              HH or Hh = H antigen; hh = Bombay)                                  (ii = blood type O)                                                                                IAIB = type AB; IAIA or IAi = type A; IBIB or IBi = type B)                         Bombay                          →                          H antigen                                  →                   blood types A, B, or AB What is the phenotype of the following individual: HhIAi?

Consider the following three genes in Mendel’s pea plants: Tall height (T) is dominant over dwarf height (t) Green pods (G) is dominant over yellow pods (g) Round seeds (R) is dominant over wrinkled seeds (r)   In a cross between the parents, TtGgrr x TtggRr, what proportion of offspring will be tall and produce yellow pods and round seeds. (HINT: consider each gene separately and then apply the product rule)

 Pfeiffer syndrome shows autosomal dominant inheritance. What is the phenotype of a heterozygous individual?

Brittle bone disease type 1 shows autosomal dominant inheritance. Daniel is an affected male who would like to have a child with his unaffected partner but is worried about transmitting the affected allele to offspring. Daniel’s mother was also affected, but his father was not. Assuming complete penetrance, what is the expected phenotype of his offspring? 

Hegemonic sports culture is routinely perceived as: