TLS Online TPP Program

#Question id: 1253


Following statements are regarding to the wnt signalling.

A. Wnt proteins interact with several cell-surface proteins and activate multiple downstream signal transduction pathways. The principal signaling receptor for Wnt proteins is Frizzled (Fz), which contains seven transmembrane α helices.

B. The palmitate attached to the Wnt protein binds to a specific site on the Fz intracellular domain and stabilizes the Wnt-Fz complex.

C. “canonical” Wnt signaling pathway uses a second transmembrane protein, LRP, that associates with Frizzled in a Wnt signal– dependent manner.

D. In the resting state, two kinases in the complex, casein kinase 1 (CK1) and GSK3, sequentially phosphorylate β-catenin on multiple tyrosine residues.

Which of the following statements are correct?

#Unit 4. Cell Communication and Cell Signaling
  1. A and C

  2. A and B

  3. B and D

  4. A, B and D

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TLS Online TPP Program

#Question id: 13132

#Unit 10. Ecological Principles

Biologists performed an experiment with flies to examine the effects of population size on the maintenance of genetic variation  and  on  egg-to-adult survival.  From  a  large  source  population, they  randomly  assigned  eggs  to  three experimental  populations  of  size  N,  equal  to  20,  60,  and0100.  For  later  generations,  they  collected  N  eggs  from each  population  and  moved  them  into  identical  vials  that  co0ntained  f2re0sh  me4d0ium.  Th6e0y  coun8te0d  the  number  of adult flies that emerged and used tissue samples from the adults for genetic analyses. Genetic variation was measured by  scoring  alleles  at  several  polymorphic  loci  and  expressed  as  the  average  number  of  alleles  at  those  loci.  The results are summarized in Figure 1 and Figure 2 below.

Which other process appears to have substantially influenced the outcome of this experiment? 

TLS Online TPP Program

#Question id: 13131

#Unit 10. Ecological Principles

Biologists performed an experiment with flies to examine the effects of population size on the maintenance of genetic variation  and  on  egg-to-adult survival.  From  a  large  source  population, they  randomly  assigned  eggs  to  three experimental  populations  of  size  N,  equal  to  20,  60,  and0100.  For  later  generations,  they  collected  N  eggs  from each  population  and  moved  them  into  identical  vials  that  co0ntained  f2re0sh  me4d0ium.  Th6e0y  coun8te0d  the  number  of adult flies that emerged and used tissue samples from the adults for genetic analyses. Genetic variation was measured by  scoring  alleles  at  several  polymorphic  loci  and  expressed  as  the  average  number  of  alleles  at  those  loci.  The results are summarized in Figure 1 and Figure 2 below.


The numbers of adult flies that emerged from the three populations in the first generation are closest to which of the following?


TLS Online TPP Program

#Question id: 13130

#Unit 10. Ecological Principles

Biologists performed an experiment with flies to examine the effects of population size on the maintenance of genetic variation  and  on  egg-to-adult survival.  From  a  large  source  population, they  randomly  assigned  eggs  to  three experimental  populations  of  size  N,  equal  to  20,  60,  and0100.  For  later  generations,  they  collected  N  eggs  from each  population  and  moved  them  into  identical  vials  that  co0ntained  f2re0sh  me4d0ium.  Th6e0y  coun8te0d  the  number  of adult flies that emerged and used tissue samples from the adults for genetic analyses. Genetic variation was measured by  scoring  alleles  at  several  polymorphic  loci  and  expressed  as  the  average  number  of  alleles  at  those  loci.  The results are summarized in Figure 1 and Figure 2 below.


Which process best explains the dynamics of genetic variation observed in this experiment? 

TLS Online TPP Program

#Question id: 13129

#Unit 10. Ecological Principles

Biologists performed an experiment with flies to examine the effects of population size on the maintenance of genetic variation  and  on  egg-to-adult survival.  From  a  large  source  population, they  randomly  assigned  eggs  to  three experimental  populations  of  size  N,  equal  to  20,  60,  and0100.  For  later  generations,  they  collected  N  eggs  from each  population  and  moved  them  into  identical  vials  that  co0ntained  f2re0sh  me4d0ium.  Th6e0y  coun8te0d  the  number  of adult flies that emerged and used tissue samples from the adults for genetic analyses. Genetic variation was measured by  scoring  alleles  at  several  polymorphic  loci  and  expressed  as  the  average  number  of  alleles  at  those  loci.  The results are summarized in Figure 1 and Figure 2 below.

Based on Figure 1, which of the following best describes the change in genetic variation over time? 

TLS Online TPP Program

#Question id: 13128

#Unit 10. Ecological Principles

Which point in the graph shows -Both population and per capita growth rates are positive but decelerating


TLS Online TPP Program

#Question id: 10230

#Unit 10. Ecological Principles

Closely related species whose populations are sometimes allopatric showing greater morphology similarity but in a sympatric with distinct morphology due to