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TLS Online TPP Program

#Question id: 15834

You are interested in a new type of autosomal dominant mutation that gives purple eyes in Drosophila. You have a true-breeding purple-eyed line carrying a mutation that you call pr-1. You have isolated a second purple-eyed mutation that you call pr-2, which you have established in a true-breeding line that also carries a recessive marker st, which gives stubby legs. You cross a fly from the pr-1 line to a fly from the st, pr-2 line producing F1 females which you then cross to males from a true breeding st line (normal eyes). From this cross, 1000 progeny flies can be categorized into four different phenotypic classes:
                             
Normally, 3-factor crosses give eight different phenotypic classes, why does this particular cross give only four?

#Unit 8. Inheritance Biology
  1. two of the mutations of interest give the same phenotype.
  2. Because the two gene are linked.
  3. Because one of this is double croosover.
  4. two of the mutations of interest shows the different phenotype.
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TLS Online TPP Program

#Question id: 15450

#Unit 4. Cell Communication and Cell Signaling

T-cell dependent response requires a signal is provided by an activated T cell, which binds to the B cell through,
a) lipopolysaccharide moiety
b) its antigen receptor 
c) A separate interaction between CD40L on the B cell and CD40 (CD154) on the activated TH cell
d) A separate interaction between CD40 on the B cell and CD40L (CD154) on the activated TH cell
TLS Online TPP Program

#Question id: 15451

#Unit 4. Cell Communication and Cell Signaling

T-cell dependent, B-cell activation require many signals except___
TLS Online TPP Program

#Question id: 15452

#Unit 4. Cell Communication and Cell Signaling

During  activation of B-cell, T cell delivers cytokines and other signals to its partner B cell. Which types of cytokine signals secreted by T-cells?
TLS Online TPP Program

#Question id: 15453

#Unit 4. Cell Communication and Cell Signaling

Activated B cells divide and differentiate into antibody-producing plasma cells, this process occurred in 
TLS Online TPP Program

#Question id: 15454

#Unit 4. Cell Communication and Cell Signaling

B cells migrate to the lymphoid follicles, they are directed by chemokine interaction_________, which is secreted by follicular dendritic cells (FDCs)
TLS Online TPP Program

#Question id: 15455

#Unit 4. Cell Communication and Cell Signaling

Variable region of antibody containing sequence motif DGYW/WRCH, which are responsible for mutation, where R, W, H represented as____