Answer:
The binding of ACh to the muscarinic receptor indirectly affects the permeability of K⁺channels. This can produce hyper polarization in some organs if channels are opened, and depolarization in others if channels are closed.
Explanation:
For example, in the heart it is the beta-gamma compound that fixes to the K+ channels of heart muscle and sources them to exposed. This leads to K+ dispersion out of the cell and the cell converts into hyper polarized consequential in a reduction in heart rate. In contrast, in smooth muscle of the stomach the alpha sub unit fixes to K+ channels producing them to close. This decreases the external diffusion of K+ and the cell converts depolarized ensuing in smooth muscle contraction.
Answer:
B) oaks and other sexually reproducing, extant (currently living) trees
Explanation:
The biological species concept defines the species on the basis of their reproductive isolation. It states that when individuals are able to interbreed to produce fertile and viable progeny, they belong to the same species. The members of different biological species cannot interbreed. If they interbreed, either pre-zygotic or post-zygotic isolation mechanisms do not allow the production of fertile progeny.
Therefore, the biological species concept can be applied to the organisms that are able to reproduce sexually. The asexually reproducing organisms would not exhibit any reproductive isolation which is a key criterion to group organisms under different species. Among the given examples, biological species concept can be applied to the sexually reproducing extant trees such as oak.
Since we cannot deduce the reproductive isolation in sexually reproducing extinct species, the concept is not useful for dinosaurs which are extinct now.
Antihistamines are drugs that are used to treat allergic rhinitis (both seasonal and perennial) and other form of allergies that cause hives or urticaria. They can give relief when a patient has nasal congestion, sneezing or hives because of pollen, dust, or animal allergy (allergens). Second generation antihistamines such as loratidine are prescribed for seasonal allergies because they are less sedating than the first generation antihistamines.
B. Animals migrate to another part of the world
If that don’t work C
The answer is Neolithic or the New Stone Age. The Neolithic period is known for the spread of agriculture, used of stone tools and also the time where the cereal cultivation for agriculture and animal domestication were introduce and lastly the appearance of pottery is also known as a symbol during this time.
