TLS Online TPP Program

#Question id: 4235


What would be the consequence of a mutation in a bacterial cell that produces a defective aminoacyl-tRNA synthetase that attaches a lysine instead of the normal phenylalanine to tRNAs with the anticodon AAA?

#Unit 3. Fundamental Processes
  1. None of the proteins in the cell will contain phenylalanine.

  2. Proteins in the cell will include lysine instead of phenylalanine at amino acid positions specified by the codon UUU.

  3. The cell will compensate for the defect by attaching phenylalanine to tRNAs with lysinespecifying anticodons.

  4. The ribosome will skip a codon every time a UUU is encountered.

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TLS Online TPP Program

#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?

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?

TLS Online TPP Program

#Question id: 7289

#Unit 1. Molecules and their Interaction Relevant to Biology

The following scheme shows the flowering status of a plant species and the photoperiodism. Which of the following conclusions is most appropriate?

TLS Online TPP Program

#Question id: 7289

#Unit 5. Developmental Biology

The following scheme shows the flowering status of a plant species and the photoperiodism. Which of the following conclusions is most appropriate?

TLS Online TPP Program

#Question id: 7290

#Unit 5. Developmental Biology

Following figure regarding to regulatory network in the Arabidopsis shoot meristem stem-cell niche.

A. The transcription factor WUS is synthesized in the cell A and moves via plasmodesmata into cell B, where one of its functions is to induce expression of the CLV3.

B. The transcription factor CLV3 is synthesized in the cell A and moves via plasmodesmata into cell B, where one of its functions is to induce expression of the WUS.

C. Secreted CLV3 protein from cell B binds to the receptor protein kinase on the surface of cell A; there, it activates a signal that represses WUS transcription.

D. Secreted WUS protein from cell B binds to the receptor protein kinase on the surface of cell A; there, it activates a signal that represses CLV3 transcription.

Which of the following combination is correct?

TLS Online TPP Program

#Question id: 7291

#Unit 5. Developmental Biology

Five different genes are known to specify floral organ identity in Arabidopsis: APETALA1 (AP1), APETALA2 (AP2), APETALA3 (AP3), PISTILLATA (PI), and AGAMOUS (AG).

Which one of the following statement is incorrect?