<span>The avian heart has evolved into a large and powerful organ with rapid muscular contractions. Generally the smaller the species the larger the relative heart size. Generally birds have hearts larger and ones that beat faster than mammals. The human heart weight amounts to .42 percent of body weight and the pulse rate at rest averages 72 beats per minute. The House Sparrow's heart constitutes 1.68 percent of the body weight and the pulse rate at rest averages 460 beats per minute. In the Ruby-throated Hummingbird these figures rise to 2.37 percent and a pulse rate of 615.</span>
Answer:
Nerve impulse
Explanation:
A nerve impulse is transmitted through the synaptic cleft by acetylcholine. When an impulse reaches the synaptic knob, it stimulates the vesicles to move towards the presynaptic membrane releasing the acetylcholine. The transmitter substance makes the membrane permeable. An action potential is then formed along the neuron.
Answer:
human health disruption can occur when ecosystem services are no longer able to meet social needs
Answer:
chloroplasts and endoplasmic
Explanation:
Answer:
If a full circle is covering a certian area then it's probably 100 percent. (or Overcast)
