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: 22954

#Unit 5. Developmental Biology

According to the which Model, floral organ identity is regulated by tetrameric complexes of the ABCE proteins

TLS Online TPP Program

#Question id: 22955

#Unit 5. Developmental Biology

Based On ABC model during flower development, loss of class A activity results the formation of only stamen and carpel. Which of the flowering floral organs identity genes controls the class  A activity ?

TLS Online TPP Program

#Question id: 22956

#Unit 5. Developmental Biology

Individual and overlapping expression of homeotic genes in adjacent whorl of a flower determine the pattern of floral organ development. In an Arabidopsis mutant, floral organs are distributed as follows

WHORL 1 Sepal

WHORL 2 Petal

WHORL 3 Petal

WHORL 4 Sepal

Loss of function mutation in which one of the following genes would have caused the above pattern of floral organs development 

TLS Online TPP Program

#Question id: 22957

#Unit 5. Developmental Biology

floral organ development is controlled by overlapping expressions of A class , B class and C class genes in different whorls. In an Arabidopsis mutant, the floral whorls had following pattern:

Sepal àSepal àcarpel àcarpel 

Mutation in which one of the following class of gene causes above pattern.  

TLS Online TPP Program

#Question id: 22958

#Unit 5. Developmental Biology

Which of the following statement is correct regarding to the flower development in Arabidopsis?

TLS Online TPP Program

#Question id: 7288

#Unit 5. Developmental Biology

Following statements are regarding to the expression of genes in floral quartate model in Arabidopsis thaliana.

A. Sepals- AP1(heterodimer) + SEP(homodimer)

B. Petals-AP1(monomer)+PI(monomer)+AP3(monomer)+SEP(monomer)

C. Stamens- AP3(monomer)+PI(monomer)+AG(monomer)+SEP(monomer)

D. Carpels- AG(homodimer)+SEP(homodimer)

Which of the following genetic combinations are incorrect?