In a particular human family, john and his mother both have brachydactyly (a rare autosomal dominant causing short fingers). john's father has huntington disease (another rare autosomal dominant). john's wife is phenotypically normal and is pregnant. two-thirds of people who inherit the huntington (hd) allele show symptoms by age 50, and john is 50 and has no symptoms. brachydactyly is 90% penetrant. a. what are the genotypes of john's parents? b. what are the possible genotypes for john? c. what is the probability the child will express both brachydactyly and huntington disease by age 50 if the two genes are unlinked? d. if these two loci are 20 m. u. apart, how will it change your answer to part c?

How is the motion of the particles of water at 80 ⁰c different from the motion of the particles of water when it is 30 ⁰c?

How does friction with the atmosphere affect the speed of an artificial satellite

Rease is an enzyme used by plants to break down urea (a nitrogen-containing compound) into carbon dioxide and ammonia. urease urea > > > carbon dioxide and ammonia ammonia is broken down by plants into a nitrogen source plants need to grow. thus, plants could not use urea as a nitrogen source unless it was first converted to ammonia. in soybean plants there are two different kinds of urease, one produced in the seeds and the other produced in the leaves of the plant. three types of soybean plants were used in a set of experiments: normal soybeans and two mutant strains, one lacking the urease in the seeds only (strain 1) and one lacking urease in the leaves only (strain 2). experiment 1 separate areas in a field were planted with normal, strain 1, and strain 2 soybeans. all types of soybeans appeared to grow, flower, and produce seeds equally well. there were no externally detectable differences among the strains. experiment 2 small pieces of plant leaves of equal weight were obtained from each type of soybean plant and separately placed on media in culture dishes. tissue growing in this way will become an unorganized clump of cells referred to as callus. to provide a controlled nitrogen source, half the tissue samples of each type were placed on media containing urea, and the other half of the samples were placed on media containing ammonia. after 30 days, the weight gain for each of the callus samples was determined. results are shown in the table below.