TLS Online TPP Program

#Question id: 7273


Hox9 and Hox10 paralogues specify the stylopod, Hox11 paralogues specify the zeugopod, and Hox12 and Hox13 paralogues specify the autopod. This scenario has been confirmed by numerous experiments.

Which of the following experiment correctly describe this scenario?

#Unit 5. Developmental Biology
  1. If knocked out all six alleles of the three Hox10 paralogues (Hox10aaccdd) in mouse embryos, the resulting mice not only had severe axial skeletal defects, they also had no femur or patella they did have humerus.
  2. When all six alleles of the three Hox11 paralogues were knocked out, the resulting hindlimbs had tibias-fibulas but neither femur nor humerus.
  3. knocking out all the paralogous Hoxa9 and Hoxd12 loci resulted in loss of the autopod.
  4. If knocked out all six alleles of the three Hox10 and Hox11 paralogues (Hox10aaccdd) in mouse embryos, the resulting mice have no limb.
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TLS Online TPP Program

#Question id: 7304

#Unit 5. Developmental Biology

Which one of the following will be observed when auxin to cytokinin ratio is increased in the culture medium during organogenesis from tobacco pith callus?

TLS Online TPP Program

#Question id: 7305

#Unit 5. Developmental Biology

In plants, a growing mass of unorganized and undifferentiated cells that cover a wound; these cells can be induced to form a plant meristem and develop into shoots and/or roots called as

TLS Online TPP Program

#Question id: 7306

#Unit 5. Developmental Biology

A plant scientist was hired by a greenhouse operator to devise a way to force iris plants to bloom in the short days of winter. Iris normally blooms as a long-day (short-night) plant. Which of the following has the best chance of creating iris blooms in winter?

TLS Online TPP Program

#Question id: 7307

#Unit 5. Developmental Biology

Which of the following statements regarding flowering plants is correct?

TLS Online TPP Program

#Question id: 7308

#Unit 5. Developmental Biology

In Arabidopsis thaliana, the transition to flowering involves multiple factors, pathways and meristem identity genes. Following statements regarding to the mechanism and function of meristem identity genes.

 A. FT mRNA is expressed in companion cells of the leaf vein in response to multiple signals, including day length, light quality, and temperature.

 B. The FT–FD complex activates AP1 in the inflorescence meristem and SOC1 in the floral meristem, which triggers LFY gene expression.

 C. LFY and AP1 trigger expression of the floral homeotic genes.

 D. FLC acts as a negative regulator of SOC1 in the meristem and as a negative regulator of FT in the leaves.

 Which of the following is incorrect?

TLS Online TPP Program

#Question id: 7309

#Unit 5. Developmental Biology

Following statements are regarding to the molecular basis of the coincidence model in Arabidopsis.

A. In Arabidopsis under short days, there is little overlap between CO mRNA expression and daylight.

B. CO protein does not accumulate to sufficient levels in the phloem to promote the expression of the transmissible floral stimulus and the plant remains vegetative.

C. Under long days, the peak of CO mRNA abundance (at hours 12 through 16) overlaps with daylight (sensed by phyA and cryptochrome [cry]), allowing CO protein to accumulate.

D. CO activates FLC mRNA expression in the phloem, which causes flowering when the FT protein is translocated to the apical meristem.

Which of the following is incorrect?