Answer:antiviral;viruses antibiotic;infections
Explanation:
I would say Diandra, because she provides the most in depth description!
<h2>GPCRs and RTKs</h2>
Explanation:
1) Phosphorylation of receptor can terminate signal or desensitize receptor: GPCRs because when signal persists a protein kinase receptor is activated,this further catalyse the phosphorylation of several serine residue at cytosolic phase of 7 transmembrane
Phosphorylated transmembrane recognized by arrestin protein blocks interaction between trimeric G protein and receptor thus blocks signal transduction
2) Autophosphorylation of receptor can initiate signal: RTKs because receptor dimerization activates intrinsic tyrosine kinase activity by which they phosphorylate its own tyrosine residue on cytosolic phase
3) Structure contains seven transmembrane helices: GPCRs because it consists of single polypeptide and spans the membrane 7 times hence called 7 transmembrane;it recognizes external signal and activates trimeric G protein
4) Ligand binding induces conformational change in receptor: RTKs because normally RTK exist in monomeric form in absence of any ligand molecule but when any ligand molecule binds receptor starts to dimerize
5) Receptor activation causes phosphorylation of its cytosolic subunits: RTKs because when receptor gets activates the intrinsic tyrosine kinase activity by which they phosphorylate its cytosolic subunits
6) An example is the insulin receptor: Insulin receptor is present on plasma membrane and belongs to RTK family and always exist in dimeric form
7) Transports some ligands through the membrane: Neither GPCR nor RTK;ligand gets transported through the membrane through ligand gated channel
8) An example is the epinephrine receptor: Epinephrine is an endocrine hormone produced by adrenal glands in stress condition and prepare body for fight and flight;Epinephrine uses GPCR signalling pathway by four different types of membrane receptors in different tissues
9) Activate heterotrimeric G proteins directly: Transmembrane protein of GPCR recognizes the external signal and activates G protein,activated G protein binds with effector enzyme and activate it which further produce or destroy secondary messenger that carry message from cell surface to cell interior
Answer:
Option C
Explanation:
Complete Question
Which of the following situations would pose a major difficulty for applying the biological species concept?
a) Two populations of sexually reproducing plants that can be bred easily in the same location under field conditions
b) Two populations of sexually reproducing insects that can be bred easily in the same location under field conditions
c) Five snail fossils taken from the same locality during a 400,000-year time span
d) Dimorphic mating pairs of birds
e) Monomorphic mating pairs of birds
Solution -
According to the biological species concept, two or more organisms that look alike does not mean that they belong to the same species. In order to consider that two organisms belong to the same species, it is essential for them to be able to interbreed or mate.
For example –
Western meadowlarks and Eastern meadowlarks look identical to one another but they do not interbreed with each other and hence they belong to different species.
Hence, option C is correct
