At an autosomal gene locus in humans, the allele for brown eyes is dominant over the allele for blue eyes. at another gene locus, located on the x chromosome, a recessive allele produces colorblindness while the dominant allele produces normal color vision. a heterozygous brown-eyed woman who is a carrier of colorblindness has children with a blue-eyed man who is not colorblind. what is the probability that their first child will be a brown-eyed, colorblind male?

If we name the gene for the eye color with A, then the genotypes for the brown color would be AA, Aa and the genotype for the blue eyes aa.

If we name the gene for the colorblindness with B, then the genotype XbXb is for colorblind woman while XBXb and XBXB are genotypes for the woman with normal vision.

A heterozygous brown-eyed woman who is a carrier of colorblindness has genotype: Aa XBXb and a blue-eyed man who is not colorblind:  aa XBY.

P:  Aa  XBXb  x  aaXBY

F1: (Aa Aa aa aa) ½ or 50% is the probability for the brown eye, ¼ or 25% is the probability that the child would be color blind male (XBXB XBY XbXB XbY)

This means:probability that their first child will be a brown-eyed, colorblind male is ½*1/4=  1/8= 12.5%

answer:

the water molecules are transferred from the roots to the stem or top parts of the tall tree because of important properties of water which are adhesion, cohesion and capillary action. cohesion is the property of water molecules keeps water molecules in a combined state by sharing of bonds between them at the atomic level. adhesion allows the interaction of water molecules with other substances or substrate. adhesion will cause the attachment of water molecules to the wall of the vessel (xylem) of the plant. capillary action occurs when the adhesive force to the vessel wall is stronger than the cohesive force between water molecules. capillary action mimics the transfer of water from a tube or pipe. in this way water utilizes its property to transfer water from down to top level of the plant.