Following statements are regarding to the the floral quartet model and the underlying ABCDE model of organ identity determination in Arabidopsis thaliana.

A. Five floral organ identities (sepals, petals, stamens, carpels, and ovules) are specified by the formation of floral organ-specific tetrameric complexes of MADS-domain transcription factors that bind to two nearby enhancer elements, forming a DNA loop in between.

B. A complex of two class A proteins (APETALA 1) and two class E proteins  (SEPALLATA) determines petal identity.

C. A complex of one class A protein, one class E protein, and one of each of the class B proteins (APETALA 3 and PISTILLATA) determines sepal identity.

D. A complex of one class E protein, two class B proteins, and one class C protein (AGAMOUS) determines stamen identity, while a complex of two class E proteins and two class C proteins determines carpel identity.D. A complex of one class E protein, two class B proteins, and one class C protein (AGAMOUS) determines stamen identity, while a complex of two class E proteins and two class C proteins determines carpel identity.

E. A complex of one class E protein, one class C protein, and one of each of the class D proteins (SHATTERPROOF and SEEDSTICK) controls ovule identity.

Which of the following combination are correct?

#Question id: 4080

#Unit 3. Fundamental Processes

How the location of exons and introns within a gene are determined?

#Question id: 4081

#Unit 3. Fundamental Processes

Which of the following regulatory scenarios of cell-type-specific expression of fibronectin isoforms in humans is (are) consistent with information on known splicing factors?

a. A Tra-like splicing factor expressed in fibroblasts is required for inclusion of EIIIA and EIIIB exons.

b. An Sxl-like splicing factor is required in hepatocytes for exclusion of EIIIA and EIIIB exons.

c. A Tra-2-like factor enhances binding of the cleavage/polyadenylation complex in fibroblasts.

d. A Dsx-like protein is required to inhibit transcription of the fibronectin gene.

#Question id: 4082

#Unit 3. Fundamental Processes

Which of the following is (are) not involved in alternative splicing in eukaryotes?

#Question id: 4083

#Unit 3. Fundamental Processes

Differential splicing of the Ca2+-activated K+ channel gene in ciliated neurons results in

a. hair cells with different response frequencies.

b. different channel isoforms.

c. channels that open at different calcium concentrations.

d. different channel mRNAs expressed in different cells.

#Question id: 4084

#Unit 3. Fundamental Processes

The nuclear pore complex

a. is a large complex made of many different proteins.

b. is an octagonal, membrane-embedded structure with long filaments.

c. is required for transport of all molecules in or out of the nucleus.

d. binds to importin via FG-repeats.

e. hydrolyzes bound GTP to GDP

#Question id: 4085

#Unit 3. Fundamental Processes

When TAT protein fails to bind to the TAR region of the HIV transcript, which of the following statements is (are) true?