Insulin is released from pancreatic b cells when blood glucose levels increase and glucagon is released from pancreatic a cells when blood glucose levels decrease. Blood glucose concentration is tightly controlled and at the basic level it appears that glucose binds to GLUT2 receptors on b cells increasing the concentration […]

Q1. Hypophosphatemia (vitamin D-resistant rickets) is inherited as the sex-linked dominant trait. The relevant gene is found on an X chromosome. What is an expected outcome of a cross between a homozygous recessive woman and a man with hypophosphatemia? Q2. A chimeric gene containing a cloned cDNA of the coat […]

Every cell in the human body has two alleles that condense into single chromosomes held together by a centromere. These “sister” chromaatids replicate and pair with the newly made homologous chromosomes. In this exercise we will follow the movement of the chromosomes through meiosis I and II to create haploid […]

A line of Drosophila melanogaster with ebony body and sepia eyes (line A) is crossed to a line with tan body and red eyes (line B). The F1 are all tan-bodied, red-eyed. a) What proportion of gametes produced by the F1 have the dominant allele for both loci? What proportion […]