Duchenne muscular dystrophy (md) is caused by a recessive allele located on the x chromosome (xd). affected people experience progressive weakening and loss of skeletal muscle. which of the sets of genotypes below would explain how two unaffected people (neither mom or dad have md) could have a child with duchenne md? a. option 1 b. mom is xdxd and dad is xdy c. mom is xdxd and dad is xdy d. mom is xdxd and dad is xdy

Multicellular organisms use cell division, mitosis, for growth and the maintenance and repair of cells and tissues. single-celled organisms may use cell division as their method of reproduction. regardless of the reason for mitosis, the process ensures genetic continuity. what is the step in the cell cycle that ensure genetic continuity?

Two students are working together on an experiment that measures the effect of different liquid fertilizers on the thickness of plants’ stems. which is most likely to result in the greatest amount of error in their scientific experiment? a.one student measures the plant stem widths by using calipers. the other student measures the widths of the same plant stems again by using a different pair of calipers. b.one student measures the plant stem widths by using calipers. the other student types the measurements as they are taken into a computer spreadsheet. c.one student weighs liquids for the experiment by using a calibrated scale. the other student weighs liquids for the experiment by using a different calibrated scale.

Which individual below would be considered heterozygous? a.dd b.dd c.dd