Two human disorders, Prader-Willi syndrome and Angelman syndrome, occur when a small deletion in a specific region of chromosome 15 is contributed by either the father or mother, respectively. Why does this small deletion not behave as a recessive allele for either syndrome, that is, why is its loss not made up for by the good copy of the region on chromosome 15 contributed by the other parent?

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: 15849

#Unit 4. Cell Communication and Cell Signaling

Host-pathogen interactions are an ongoing arms race; pathogens evolve to express unique structures that avoid host detection, and the host germline-encoded recognition system co-evolves to match these new challenges. However, because pathogens generally have much shorter life cycles than their vertebrate hosts, and some utilize error-prone DNA polymerases to replicate their genomes, pathogens can evolve rapidly to evade host encoded recognition systems. Which error prone DNA polymerase is used  by human?

TLS Online TPP Program

#Question id: 15848

#Unit 4. Cell Communication and Cell Signaling

viruses frequently expose unique chemical structures only during their replication inside host cells. Many of these can be detected via intracellular receptors that bind exposed chemical moieties while still inside the host cell. This can trigger an immediate antiviral response in the infected cell that blocks further virus replication. At the same time, this initiates the secretion of chemical warning signals sent to nearby cells to help them guard against infection (a neighborhood watch system!). virus is not recognised which receptor?

TLS Online TPP Program

#Question id: 15847

#Unit 4. Cell Communication and Cell Signaling

Pathogen-associated molecular patterns (or PAMPs) are common foreign structures that characterize whole groups of pathogens. It is these unique antigenic structures that the immune system frequently recognizes first. Animals, both invertebrates and vertebrates, have evolved to express several types of cell surface and soluble proteins that quickly recognize many of these PAMPs; a form of pathogen profiling. For example, encapsulated bacteria possess a polysaccharide coat with a unique chemical structure that is not found on other bacterial or human cells. White blood cells naturally express a variety of receptors, collectively referred to as pattern recognition receptors (PRRs), that specifically recognize these sugar residues, sugar residues is recognised by?

TLS Online TPP Program

#Question id: 15530

#Unit 4. Cell Communication and Cell Signaling

The activity of already differentiated effector and memory T cells is maintained by a receptor which are generally expressed on the memory and effector T cells. 

TLS Online TPP Program

#Question id: 15529

#Unit 4. Cell Communication and Cell Signaling

When does the T-cell anergy occur?