By the unequal heating of earths surface
Answer:
Hemoglobin is responsible for binding and transporting oxygen in the body. It is a tetrameric protein that is found in high concentration in red blood cells (erythrocytes, red blood cells). Each hemoglobin molecule is made up of four subunits: two of the alpha type and two of the beta type, and each subunit can bind an oxygen molecule through its heme group.
Structure studies have shown that hemoglobin can adopt two conformations, called T (tense) and R (relaxed). Deoxyhemoglobin (in blue) is in state T, and the union of oxygen (in red) causes the transition to state R. The animation shows a close view of the heme group (in white, balls and rods) of one of the subunits of hemoglobin. In the deoxygenated state (T), the iron atom is not coplanar with the rest of the heme group due to its association with the histidine side chain. The union of oxygen displaces the iron atom so that it remains coplanar with the rest of the heme group, which in turn drags histidine, producing a larger-scale conformational change that affects the entire protein.
Hemoglobin can be considered as a tetramer formed by two alpha-beta dimers. The conformational change associated with the transition from T to R mainly affects the relative position of these two dimers (rather than the interactions between the alpha and beta subunits within a dimer). This is illustrated in the last stretch of the animation (drawn in black and white).
Answer:
Mechanical isolation
Explanation:
mechanical isolation is a form of prezygotic reproductive barrier, whereby similar species organisms become isolated and unable to successfully interbreed with each other to form zygote, as a result of incompatibility of their reproductive organ or structure, which prevents them from copulating. As a result of this, both species become separated as there is no gene flow between both.
The two species of juniper can be said to be kept separate by <em>mechanical isolation</em>, due to the differences and incompatibility of their reproductive structure.
Answer:A) look at a spider
Explanation:
Arachnophobia is an abnormal or irrational fear of arachnids (especially spiders). In this context a sight of the spider put him to flight.
Resolving power<span> is the ability of an imaging device to separate (i.e., to see as distinct) points of an object that are located at a small angular distance or it is the </span>power<span> of an optical instrument to separate far away objects, that are close together, into individual images.</span>
