Answer:
What if what if what if what if?
Explanation:
What if- I turn into a What if ?
Answer:Biological structures are able to adapt their growth to external mechanical stimuli and impacts. For example, when plants are under external loads, such as wind force and self-weight, the overloaded zones are reinforced by local growth acceleration and the unloaded zones stop growing or even shrink. Such phenomena are recorded in the annual rings of trees. Through his observation of the stems of spruce, K. Metzger, a German forester and author, realized that the final goal of the adaptive growth exhibited by biological structures over time is to achieve uniform stress distribution within them. He published his discovery in 1893.12 A team of scientists at Karlsruhe Research Centre adopted Metzger's observations and developed them to one single design rule: the axiom of uniform stress. The methods derived from this rule are simple and brutally successful like nature itself. An excellent account of the uniform-stress axiom and the optimization methods derived from it is given by Claus Mattheck in his book ‘Design in Nature’.13 The present study utilizes one of these methods, stress-induced material transformation (SMT), to optimize the cavity shape of dental restorations.
Explanation:
Answer:
<u>Antigenic drift</u> refers to the slow accumulation of genetic changes to an influenza virus over time.
Explanation:
Antigenic drift is defined as the mechanism by which viruses undergo variation. This mechanism involves the slow accumulation of mutations in the viral genes, that are responsible for coding the antibody binding sites. This leads to the formation of a new strain of virus, which can't be inhibited by the old antibodies. Due to this, the virus can easily spread the disease.
The antigenic drift occurs in the influenza A virus and also the influenza B viruses.
Therefore, <u>Antigenic drift refers to the slow accumulation of genetic changes to an influenza virus over time.</u>
Answer: Unicellular and microscopic features set the protista apart from the rest of the kingdom.
Explanation:
Protista are eukaryotic organisms that are neither plants, animals or fungi. They do not have a natural group with whom they share common ancestor. They have a unique features that set them apart from the rest of the kingdom which are unicellular and microscopic. Examples are amoeba, blue green algae, diatoms, green algae, ciliates and many more.
The mechanisms of reproductive isolation prevent the reproduction of two individuals from different species. The prezygotic mechanisms disrupt the stages of reproduction before the forming of the zygote or prevent the mating at the start, and the postzygotic mechanisms affect the stages of reproduction after the forming of the zygote.
So, the first and the third example (the urchins and the grasshoppers) show the prezygotic mechanism, as the two individuals are not able to mate or form a zygote.
The second and the fourth example ( zonkey and the death of a zygote) show the working of the postzygotic mechanisms, as the zygote is formed, but it seems to be inviable, and the zonkeys are sterile, preventing the individual to reproduce.
