Answer:
a) 12 neutrons
Explanation:
The atomic mass is 22.990, which can be rounded to 23 and is the combination of protons and neutrons. The atomic number is 11 (protons), and 23-11=12, whoch would be the neutron number
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Answer:
b. giving birth to live young (viviparous)
Explanation:
Monotremes include duck-billed platypus and few other mammalian species that are oviparous. These mammalian species do not give birth to young ones, that is, they are not viviparous. Rather they lay eggs and are oviparous.
These species are also characterized by the absence of teeth. The primitive monotremes also exhibit external fertilization.
Examples of egg-laying mammals include anteaters or echidnas and the duck-billed platypus. The laid eggs are carried by females in an abdominal ouch to keep them warm.
<span>Answer
1. electrical signal travels toward the heart
2. signal by the nodes in the atrium</span>
3. the atria contract<span>
</span>4. signal received by the atrioventricular node
5. signal transferred to the ventricles
6. the ventricles contract
Heart has a pacemaker that will continually send a signal. The primary site of the pacemaker is at the sinoatrial node, on the top right atrium. This node will send a signal to atria (which will cause it to contract) and to the atrioventricular node.
Atrioventricular node located between atrium and ventricle. It will send the signal to the ventricle(by the bundle of his) and cause it to contract.
