Congenital deafness in humans is due to the
homozygous condition of either of the recessive
genes d or e, or both of these genes. Both dominant
D and E are necessary for normal hearing. Gene D/d
affects the middle ear, while gene E/e affects the
inner ear. It does not matter how good the normal
inner ear (as indicated by E__) is; if there is
something wrong in the middle ear, the individual is
unable to hear. The same applies for the other gene.
Give the phenotypic results of the following crosses:
(a) Dd EE x Dd EE
(b) Dd Ee x Dd Ee
(c) dd EE x DD ee
(d) Dd EE x Dd ee
(e) Dd EE x DD Ee What will be an ideal response?
Answer: (a) 3/4 normal, 1/4 deaf
(b) 9/16 normal, 7/16 deaf
(c) all normal
(d) 3/4 normal, 1/4 deaf
(e) all normal
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The process of post-transcriptional gene silencing triggered by micro-RNA molecules that stop translation is called
____. a. RNA interference b. micro-interference c. translational interference d. transcriptional disruption e. disruptive genetic silencing
Very many related genes can be recognized by conserved protein domains. To what gene structures do these domains correlate?
What will be an ideal response?
Which of these events occurs normally in swallowing?
A) The larynx rises. B) The epiglottis rises. C) The bolus rises. D) The esophagus closes.
The rate of diffusion of molecules would be fastest in a cell with an
A. internal concentration of 50 percent and an external concentration of 12 percent in warm temperatures. B. internal concentration of 40 percent and an external concentration of 35 percent in warm temperatures. C. internal concentration of 45 percent and an external concentration of 50 percent in cold temperatures. D. internal concentration of 50 percent and an external concentration of 12 percent in cold temperatures.