TLS Online TPP Program

#Question id: 24672


Which statement describes the mode of action of the ABCB1 transporter (the first eukaryotic ABC transporter to be recognized)?

#Unit 2. Cellular Organization
  1. During transport, the ligand binding site is alternately exposed to the exoplasmic and the cytoplasmic side of the membrane.
  2. During transport, a conserved aspartate residue is phosphorylated.
  3. This class of pumps transports only H+ ions.
  4. This transporter acts as a chloride channel.
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TLS Online TPP Program

#Question id: 5135

#Unit 5. Developmental Biology

In xenopus, result of tissue transplantation during early and late gastrulae

(A) Cells of early newt gastrula exhibit conditional development.

(B) Cells of early newt gastrula exhibit autonomous development

(C) Cells of late newt gastrula exhibit conditional development.

(D) Cells of late gastrula exhibit autonomous development.

The correct inferences are:

TLS Online TPP Program

#Question id: 5136

#Unit 5. Developmental Biology

Some statements regarding to hippo pathway.

A. The Hippo signal transduction pathway have a dedicated ligand or receptor

B. Hippo stands for one of several important kinases that are critical for organ size control

C. It was first identified in Drosophila, where its loss resulted in a “hippopotamus”-shaped phenotype due to excessive growth

D. Gain of Hippo causes cells to divide significantly faster while slowing apoptosis

E. overexpression of its main transcriptional effector, Yorkie causes cells to divide significantly faster while slowing apoptosis

Which of the following combination are incorrect?

TLS Online TPP Program

#Question id: 5137

#Unit 5. Developmental Biology

Match the correct animal and their mechanism of germplasm specification.

Animal

Specification of germ cells

a. Drosophila

i. germplasm is characterized by polar granules and PIE-1 protein, and segregates into P4 during cleavage 

b. Xenopus                                                

ii. germplasm localized in vegetal region of egg

c. mammals

iii. germplasm specified by oskar at posterior end of egg

d. c. elegans

iv. Have no germplasm

TLS Online TPP Program

#Question id: 5138

#Unit 5. Developmental Biology

When presomitic mesoderm (PSM) that would ordinarily form thoracic somites is transplanted into a region in a younger embryo (caudal to the first somite) that would ordinarily give rise to cervical (neck) somites, the grafted mesoderm differentiates according to its original position and forms ribs in the neck. This phenomena is called as:

TLS Online TPP Program

#Question id: 5139

#Unit 5. Developmental Biology

There are two broad categories of receptors that activate tyrosine kinases: (1) those in which the tyrosine kinase enzyme is an intrinsic part of the receptor’s polypeptide chain, called the_________ and (2) those, in which the receptor and kinase are separate polypeptides, encoded by different genes, yet are bound tightly together, called the __________.

TLS Online TPP Program

#Question id: 5140

#Unit 5. Developmental Biology

Following statements regarding to the Ectodermal competence and the ability to respond to the optic vesicle inducer in Xenopus.

A. The optic vesicle is able to induce lens formation in the posterior portion of the ectoderm but not in the anterior portion.

B. If the optic vesicle is removed, the surface ectoderm forms either an abnormal lens or no lens at all.

C. Only head ectoderm is competent to respond to the signals from the optic vesicle by producing a lens.

D. The head ectoderm appears to secrete two paracrine factors BMP 4 and FGF8, which involves in the activation of lens-specific genes such as crystallin.

Which of the following combination is incorrect?