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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: 11258

#Unit 10. Ecological Principles

In order for mimicry to be effective in protecting a species from predation, it must
TLS Online TPP Program

#Question id: 5123

#Unit 5. Developmental Biology

The generation of specialized cell typces is called ‘differentiation’, a process during which-
TLS Online TPP Program

#Question id: 794

#Unit 1. Molecules and their Interaction Relevant to Biology

A single-stranded DNA molecule contains 40 nucleotides with equal amounts of A, C, G, and T. This DNA strand can combine with a complementary DNA strand to form a double-stranded DNA molecule. Which structural feature is found in the single-stranded DNA molecule?
TLS Online TPP Program

#Question id: 604

#Unit 1. Molecules and their Interaction Relevant to Biology

An enzyme is irreversibly inhibited by diisopropylfluorophosphate (DFP). What does this show?
TLS Online TPP Program

#Question id: 10308

#Unit 1. Molecules and their Interaction Relevant to Biology

Oxidative decarboxylation of pyruvate to acetyl-CoA by the PDH complex, how the pyruvate dehydrogenase complex carries out the five consecutive reactions in the decarboxylation and dehydrogenation of pyruvate?

 A) Pyruvate reacts with the bound thiamine pyrophosphate (TPP) of pyruvate dehydrogenase, undergoing decarboxylation to the hydroxyethyl derivative

 B) A transesterification in which the —SH group of CoA replaces the —SH group of E2 to yield acetyl-CoA and the fully reduced (dithiol) form of the lipoyl group

 C) The reduced FADH2 of E3 transfers a hydride ion to NAD1 , forming NADH, the enzyme complex is now ready for another catalytic cycle

 D) The transfer of two electrons and the acetyl group from TPP to the oxidized form of the lipoyllysyl group of the core enzyme, dihydrolipoyl transacetylase, to form the acetyl thioester of the reduced lipoyl group

 E) Dihydrolipoyl dehydrogenase promotes transfer of two hydrogen atoms from the reduced lipoyl groups of E2 to the FAD prosthetic group of E3 , restoring the oxidized form of the lipoyllysyl group of E2

 Find out the correct sequence of action of this complex enzyme?