Answer: (B) At the exterior surface
Explanation:
G protein-linked receptors (GPLR) are also called G protein-coupled receptors, 7-Transmembrane receptors or heptahelical receptors. They conform a large protein family of receptors.
They helps to detect molecules (ligands) outside the cells. (At the exterior surface).
The LIGANDS that binds and activate these receptors include light-sensitive compounds (Opsins), odorants (olfactory receptors), pheromones (vomeronasal receptors which are situated near the vomer bone between the nose and the mouth), hormones and neurotransmitters (serotonin, dopamine, glutamate etc).
Let's take a bird's eye view at it.
° When a Ligand binds with a G protein-linked receptors (which occurs at the exterior surface), it undergoes a conformational change.
° As conformational change occurs, GPLR become active and interact with the G-proteins Heterotrimeric Subunits ( G-alpha, G-beta, G-gamma) in the plasma membrane (at the cytosol surface).
This step typically explains the ambiguity. i.e GPLRs receptors interacts with signaling ligands via the exterior surface but communication between GPLRs and G-proteins Heterotrimeric Subunits occurs in the cytosol membrane.
Hence, this Conformational Change then triggers the interaction between the GPLRs and a nearby G proteins.
I hope that helps!.
Answer:
interphase
Explanation:
The cell cycle is divided into two main phases: interphase and mitotic phase (mitosis or meiosis).
Interphase is phase characterized by the the cell growth and DNA copy (replication). During this phase, the cell prepares for division, (mitotic phase).
Interphase has three phases:
G1 or Gap 1 - the cell grows in size and duplicates organelles
S1-replication of DNA
G2 or Gap 2 phase- the cell adds volume to the cytoplasmand repicates more organelles.
Answer:
A. True
Explanation:
Apoptosis is a normal cellular process in which the cell inherently programs the death of a mutated or damaged cell without affecting the healthy condition of the other surrounding cells by proliferating.
Apoptosis is a system of checks and balances that the cell uses to prevent damaged or mutated cells from proceeding to the next phase in the cell cycle. This curbs or prevent the damaged cell from passing on the problem to its daughter cells. Hence, according to this question, it is TRUE.
Answer:
it results in 2 exact copies of the original dna strand
Explanation:
The dna is unzipped and the two strands are used as templates for the 2 new dna molecules
Answer no 8:
The correct option is D) Antelopes with muscular legs are bale to outrun their predators better than antelopes with poor muscle tone. Thus they lived to reproduce.
Explanation:
Genetic variations in a population are the main reason that natural selection tends to occur. Natural selection favours those organisms which have better characteristics.The organisms with better traits are able to reproduce and pass on their characteristics to their offsprings.
Answer No 10:
The correct option is A) Phenotype directly influences the interaction of an organism with its environment.
Explanation:
The interactions between the phenotypic traits and the environment analyze whether a particular organism will be able to survive and pass on its characteristics to its offspring. Hence, the phenotype directly influences the interaction of an organism with its environment.
Answer No 9
The correct option is A) resistance to a virus
Explanation:
Mutations can be described as any changes which occur in the DNA of an organism. Mutations might be beneficial or harmful depending on the location where the mutation arises. Viruses are usually harmful for eukaryotes. Hence, the correct option is A.
Answer No 11:
The correct option is C) Giraffes with longer necks survived because they were better suited to the environment.
Explanation:
Natural selection tends to favour those organsims which are better suited to live in an environment. Those organisms with better characteristics are able to survive and pass on their traits to their offsprings.
The giraffes with longer necks were better adapted to live in the environment and hence were favoured by natural selection.
Answer No 12:
The correct option is D) selective breeding
Explanation:
Selective breeding can be described as a technique in which organisms with better characteristics are crossed, so that offsprings with better characteristics can be produced. Selective breeding is done by humans where as natural selection is done by the nature.
