Mitotic CDK complexes are maintained in an inactive state through inhibitory phosphorylation of the CDK subunit. Two highly conserved tyrosine and threonine residues in mammalian CDKs are subject to regulated phosphorylation.

Gene	Mutant phenotypes
A. Wee1	i. the cell does not divide but continues to grow
B. CAK kinase	ii. mitotic cyclins are inactivated
C. cdc25 phosphatase	iii. premature entry into mitosis

The following table enlists genes and phenotypes observed on mutation of these genes but not correctly matched. Which one of the following combinations is correctly matched ?

#Question id: 7287

#Unit 5. Developmental Biology

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: 6942

#Unit 5. Developmental Biology

How long does embryonic development (before 1st instar larva hatches) take in this organism?

#Question id: 6943

#Unit 5. Developmental Biology

The portion of the blastoderm-stage embryo which will give rise to most ectodermal, mesodermal, and endodermal tissues is called the:

#Question id: 6944

#Unit 5. Developmental Biology

Which would lead to a dorsalized embryo? (Recall that genes in Drosophila are named for their mutant phenotype.

#Question id: 6945

#Unit 5. Developmental Biology

The portion of the Drosophila body plan which will produce the wing is called

#Question id: 6946

#Unit 5. Developmental Biology

The adult body plan of the fly is based on reiterating structures called segments; segment precursors (parasegments) are first positioned at the cell-by-cell level by which group of genes?