It is shaped by a Mediterranean climate (mild, wet winters and hot dry summers) and wildfire, featuring summer-drought-tolerant plants with hard sclerophyllous evergreen leaves, as contrasted with the associated soft-leaved, drought-deciduous, scrub community of coastal sage scrub, found below the chaparral biome.n its natural state, chaparral is characterized by infrequent fires, with intervals ranging between 10â15 years to over a hundred years.
Echo is caused by reflection of the sound from a broad and hard obstacle. The echo can be heard if the following condition is met. To hear a distinct echo, the time interval between original sound and the reflection must be at least 0.1s.
1. Explain why ventricular contraction (systole) and the 'lub' sound occur immediately after the QRS complex. The lub sound occurs during the beginning stages of systole (ventricular contraction) and when the atrioventricular valves, which prevents blood from flowing back into the atria. The QRS complex is the first heart beat of the cycle, so directly after the heart beat or QRS complex, the valves close to prevent backflow and makes the âlubâ sound. 2. Explain why ventricular relaxation (diastole) and the 'dup' sound occur after the T wave. The T wave is the wave produced by the relaxation of the ventricles, which causes the blood pressure to drop and when the semilunar valves close, the âdupâ sound is made. 3.