B)<span>When you listen to the heart sounds, you are hearing the flow of blood which stops abruptly when a heart valve closes. This produces the "lub-dub" sounds. 1st heart sound (when the Mitral Valve closes) as the ventricle contracts (systole) and then 2nd heart sound (when the Aortic Valve closes) and the ventricle starts to fill again (diastole)
</span><span>The pulse is the wave of pressure you can feel through the artery walls. This denotes systole.
</span><span>The ECG's QRS complex is the electrical signal that tells the Ventricles to contract. You can see that the QRS occurs right at the beginning of systole and triggers Isovolumetric contraction.
</span><span>So the QRS on the ECG, the pulse wave you can feel (ie. the rise in aortic pressure) and the 1st heart sound all signify SYSTOLE.
</span><span>there a delay between systole of the ECG and the resulting pulse felt in the finger (R-Pulse) </span>because it takes a little bit of time for the pressure to transmit through the body, as the finger is not on the heart (if it was there would be no delay)
Answer:
d. introduce native flowering plants the adult butterflies need for nectar, their main food.
Explanation:
Organisms choose the habitat based on the availability of basic requirements such as food, nutrients, space, etc. in the region. The absence of one or more of these factors makes them choose another habitat. Butterflies feed on nectar made by plants in their flowers. To make the butterflies stay in the landscape, flowering plants adapted to local conditions should be planted. The butterflies would feed on the nectar of these plants and would stay in the landscape.
Water, soil, sunlight, H20, and nutrients.
The correct answer to this question is this one: a.) bottleneck effect. Increased poaching nearly led to the extinction of the American bison. The kind of effect that does this example represent is called the bottleneck effect. Hope this helps answer your question.
Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in heritable traits of a population over time. The term "natural selection" was popularised by Charles Darwin who compared it with artificial selection, now more commonly referred to as selective breeding.
