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 ? Dd EE
(b) Dd Ee ? Dd Ee
(c) dd EE ? DD ee
(d) Dd EE ? Dd ee
(e) Dd EE ? DD Ee What will be an ideal response?
(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
You might also like to view...
How has flight been at least partly responsible for the success of the insects? Because of flight,
What will be an ideal response?
Which of the following is NOT involved in turning off the lac operon?
a. the short lifespan of mRNA molecules b. the short lifespan of the lac operon gene products c. the depletion of lactose from the cytosol d. the lack of allolactose to bind to the repressor e. binding of repressor to the operator
The difference between direct and indirect immunofluorescence testing is that
A. Indirect testing determines the identity of an unknown antigen in a patient sample, whereas direct testing determines whether the patient has been exposed to an antigen as evidenced by the presence of antibodies in their sera. B. Direct testing adds antibodies directly to antigens, whereas indirect testing cultures the organisms first and adds fluorescent tags to the patient sample. C. Direct testing determines the identity of an unknown antibody in a patient sample, whereas indirect testing determines whether the patient is infected with a specific antigen. D. Direct testing determines the identity of an unknown antigen in a patient sample, whereas indirect testing determines whether the patient has been exposed to an antigen as evidenced by the presence of antibodies in their sera.
Precarcinogens are themselves not carcinogens but may be modified in the liver to become a carcinogen by a process known as ________
Fill in the blank with correct word.