In dark-adapted rod cells, a high level of cGMP keeps cGMP-gated nonselective cation channels open, leading to hyperpolarization of the plasma membrane and neurotransmitter release. 

B - Light absorption generates activated rhodopsin, R*, which binds inactive, GDP-bound Gαt protein and mediates the exchange of GDP for GTP . 

C- The free Gαt∙GTP activates PDE by binding to its inhibitory γ subunits and dissociating them from the catalytic α and β subunits . Relieved of their inhibition, the α and β subunits of PDE hydrolyze GMP to cGMP . 

D- The resulting decrease in cytosolic cGMP leads to dissociation of cGMP from the cation channels in the plasma membrane and the closing of those channels . 

E- The membrane then becomes transiently hyperpolarized, and neurotransmitter release is reduced. 

TLS Online TPP Program

#Question id: 18083

#Unit 8. Inheritance Biology

The interaction of selection and inbreeding in determining the incidence of autosomal recessive diseases. Consider a gene in which recessive mutations occur at a rate of 10^-5. Assume a selective disadvantage S of 0.4 in homozygotes for the recessive allele. Would q be expected to rise, fall, or remain unchanged during the first 10 generations after the cessation of inbreeding, Briefly justify your answer. What numerical value would q approach after thousands of generations with no inbreeding?

TLS Online TPP Program

#Question id: 18227

#Unit 8. Inheritance Biology

You are conducting genetic linkage studies of an autosomal dominant disease. You are focused on two SSR markers that may be linked to each other and to the disease. Here is a family in which some individuals are affected:

 

Calculate LOD scores for linkage at θ = 0.1 between the disease and SSR62

TLS Online TPP Program

#Question id: 18228

#Unit 8. Inheritance Biology

You are conducting genetic linkage studies of an autosomal dominant disease. You are focused on two SSR markers that may be linked to each other and to the disease. Here is a family in which some individuals are affected:

 

Calculate LOD scores for linkage at θ = 0.1 between the disease and SSR93?

TLS Online TPP Program

#Question id: 18229

#Unit 8. Inheritance Biology

You are conducting genetic linkage studies of an autosomal dominant disease. You are focused on two SSR markers that may be linked to each other and to the disease. Here is a family in which some individuals are affected:

 

Calculate LOD scores for linkage at θ = 0.1 between SSR62 and SSR93

TLS Online TPP Program

#Question id: 18969

#Unit 8. Inheritance Biology

Consider the ABO “blood type” gene. This single gene has three alleles called A, B, and O. There are four resultant “blood types” (phenotypic classes), as follows:C

                               

Assume Hardy-Weinberg equilibrium. In Norway, the frequencies of the A and B alleles are 0.26 and 0.07, respectively. What is the frequencies of these six genotypes (AA, AO, BB, BO, AB, and OO);

TLS Online TPP Program

#Question id: 18970

#Unit 8. Inheritance Biology

Consider the ABO “blood type” gene. This single gene has three alleles called A, B, and O. There are four resultant “blood types” (phenotypic classes), as follows:

                                     

Assume Hardy-Weinberg equilibrium,  the frequencies of the A and B alleles are 0.26 and 0.07, respectively. What is the frequencies of the four blood types such as A, B, AB  and O in Norway;