Stage thymocytes express neither CD4 nor CD8, markers associated with mature T cells. They are therefore called double negative (DN) cells. DN cells first travel to the region under the thymic capsule, a region referred to as the ________, where they proliferate and begin to generate their T-cell receptors. Thymocytes that successfully express TCRs begin to express both CD4 and CD8, becoming double positive (DP) cells, and populate the cortex, the site where most (85% or more) immature T cells are found.

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#Question id: 106

#Unit 1. Molecules and their Interaction Relevant to Biology

fatty acid designated as 20:0 is ________, while one that is designated 20:3 D5,8,11 is

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#Question id: 2031

#Unit 4. Cell Communication and Cell Signaling

Antigen binding sites of an immunoglobulin are located in

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#Question id: 7178

#Unit 5. Developmental Biology

In sea urchin, the large micromeres are autonomously specified. They inherit maternal determinants that were deposited at the vegetal hemisphere of the egg; these become incorporated into the large micromeres at fourth cleavage. When an isolated animal hemisphere is combined with isolated micromeres, then what will be the result?

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#Question id: 14839

#Unit 5. Developmental Biology

Given are certain facts which define ‘specification’ of a developing embryo.

 A. At the specification stage, commitment to cell identity is labile.

 B. At the specification stage, cell is capable of differentiating autonomously.

 C. The cell “knows” very early what it is to become without interacting with other cells.

 D. A phase where inductive signals trigger cell to determines their fate.

 Which of the above statements best define specification?

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#Question id: 697

#Unit 1. Molecules and their Interaction Relevant to Biology

The major reason that antiparallel B-stranded protein structures are more stable than parallel B-stranded structures is that the latter: