TLS Online TPP Program

#Question id: 16146


If a given lymphocyte divides to form two daughter cells, both daughters bear antigen receptors with antigen specificities identical to each other and to the parental cell from which they arose, and so will any descendants they produce. The resulting population of lymphocytes, all arising from the same founding lymphocyte, is a clone. Which interleukin is responsible for clone production?

#Unit 4. Cell Communication and Cell Signaling
  1. CXCL12
  2. CXCl13
  3. IL-2
  4. IL-6
More Questions
TLS Online TPP Program

#Question id: 9621

#Unit 9. Diversity of Life Forms

If this evolutionary tree is an accurate depiction of relatedness, then which of the following should be correct?

1. The entire tree is based on maximum parsimony.

2. If all species depicted here make up a taxon, this taxon is monophyletic.

3. The last common ancestor of species B and C occurred more recently than the last common ancestor of species D and E.

4. Species A is the direct ancestor of both species B and species C.

5. The species present at position 3 is ancestral to C, D, and E


TLS Online TPP Program

#Question id: 9620

#Unit 9. Diversity of Life Forms

The two extant species that are most closely related to each other are

TLS Online TPP Program

#Question id: 9619

#Unit 9. Diversity of Life Forms

A common ancestor for both species C and E could be at position number 

TLS Online TPP Program

#Question id: 9617

#Unit 9. Diversity of Life Forms

The common ancestors of birds and mammals were very early (stem) reptiles, which almost certainly possessed 3-chambered hearts (2 atria, 1 ventricle). Birds and mammals, however, are alike in having 4-chambered hearts (2 atria, 2 ventricles). The 4-chambered hearts of birds and mammals are best described as

TLS Online TPP Program

#Question id: 9615

#Unit 9. Diversity of Life Forms

In angiosperm plants, flower morphology can be very intricate. If a tree, such as a New Mexico locust, has flowers that share many morphological intricacies with flowers of the sweet pea vine, then the most likely explanation for these floral similarities is the same general explanation for the similarities between the

TLS Online TPP Program

#Question id: 9614

#Unit 9. Diversity of Life Forms

Some molecular data place the giant panda in the bear family (Ursidae) but place the lesser panda in the raccoon family (Procyonidae). Consequently, the morphological similarities of these two species are probably due to