TLS Online TPP Program

#Question id: 809


A single-stranded DNA molecule contains 40 nucleotides with equal amounts of A, C, G, and T. This DNA strand can combine with a complementary DNA strand to form a double-stranded DNA molecule. Which of the following double-stranded DNA molecules would denature at a lower temperature than the 40 base-pair double-stranded molecule described above?

#Unit 1. Molecules and their Interaction Relevant to Biology
  1. a 40 base-pair molecule in which 25% of the bases are adenines

  2. a 30 base-pair molecule in which 40% of the bases are guanines

  3. a 20 base-pair molecule in which 10% of the bases are thymines

  4. a 10 base-pair molecule in which 20 % of the bases are cytosines

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TLS Online TPP Program

#Question id: 15850

#Unit 4. Cell Communication and Cell Signaling

For innate and adaptive immunity to work together, these two systems must be able to communicate with one another. This communication is achieved by both cell-cell contact and by soluble messengers. Most of these soluble proteins are growth factor–like molecules known by the general name cytokines. Which of these molecule can work as communicator between innate and adaptive immunity?

TLS Online TPP Program

#Question id: 16141

#Unit 4. Cell Communication and Cell Signaling

Indicate to which branch of the immune system the following statements apply, using H for the humoral branch and CM for the cell-mediated branch. Which cells involve in both response?

TLS Online TPP Program

#Question id: 16142

#Unit 4. Cell Communication and Cell Signaling

Stem cells are defined by two capacities:
(1) the ability to regenerate or “self-renew” and
(2) the ability to differentiate into all diverse cell types. Embryonic stem cells have the capacity to generate every specialized cell type in an organism, in other words,

TLS Online TPP Program

#Question id: 16143

#Unit 4. Cell Communication and Cell Signaling

undifferentiated hematopoietic stem cells would not express surface markers specific for mature cells from the multiple blood lineages (“Lin” markers). They used several approaches to eliminate cells in the bone marrow that did express these markers (Lin+ cells) and then examined the remaining (Lin+) population for its potential to continually give rise to all blood cells over the long term. Lin- cells were, indeed, enriched for this potential. what marker is   express If cells inter in lymphoid lineages?

TLS Online TPP Program

#Question id: 16144

#Unit 4. Cell Communication and Cell Signaling

  _______are motile phagocytic cells they play their most important role in the defense against multicellular parasitic organisms, including worms. They can be found clustering around invading worms, whose membranes are damaged by the activity of proteins released from its granules. it may also secrete cytokines that regulate B and T lymphocytes, thereby influencing the adaptive immune response.

TLS Online TPP Program

#Question id: 16145

#Unit 4. Cell Communication and Cell Signaling

 Which line is not true for follicular dendritic cells?