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. 

#Question id: 4822

#Unit 8. Inheritance Biology

In a particular species of mammal black hair (B) is dominant to green hair (b) and red eyes (R) are dominant to white eyes (r). If a BbRr individual is mated with a bbrrindividual the expected phenotypic ratio of the offspring is 1 black-red : 1 black-white: 1 green-red : 1 green-white. However, when you mate these individuals you find that the phenotypic ratio of the offspring is 6 black-red :1 black-white : 1 green-red : 6 green-white. What could account for this difference?

#Question id: 4823

#Unit 8. Inheritance Biology

Which one of the following DNA markers can be used to distinguish between a homozygote and heterozygote ?

#Question id: 4824

#Unit 8. Inheritance Biology

If plant with genotype AaBb is test cross where A and B are link at 10 map unit  in trance configuration then the probability of getting AaBB and AaBb genotype respectively?

#Question id: 4825

#Unit 8. Inheritance Biology

How many genetically different gametes can be made by an individual of genotype AaBbCcDd if gene A, B are completely link and other are unlink?

#Question id: 4826

#Unit 8. Inheritance Biology

In Drosophila melanogaster, vestigial wings are determined by a recessive allele of a gene that is linked to a gene with a recessive allele that determines black body color. T. H. Morgan crossed black-bodied, normal-winged females and gray-bodied, vestigial-winged males. The F1 were all gray bodied, normal winged. The F1 females were crossed to homozygous recessive males to produce testcross progeny. Morgan calculated the map distance to be 17 map units. Which of the following information is correct about the testcross progeny?

#Question id: 4828

#Unit 8. Inheritance Biology

Consider two pairs of alleles, G/g and H/h, that follow complete dominance inheritance. The initial cross consisted of GG hh males and gg HH females, and the F I female progeny were test crossed with gg hh males to produce 380 Gghh progeny out of 1000 total progeny. What is approximate distance between Gene G and H.