Rigid skeletons are formed from materials including chitin (in arthropods), calcium compounds such as calcium carbonate (in stony corals and mollusks) and silicate (for diatoms and radiolarians).
<span>The probability of an action potential being propagated from neuron to neuron is increased when the postsynaptic neuron's signal is in an excitatory state. During this state, the action potential of a presynaptic neuron increases the probability of transmission of a signal to the postsynaptic neuron.</span>
<span>Answer: 1/4 AA or type A Blood; 1/4 BB or type B Blood; 1/2 AB</span>
Cortisol hormones are stress hormones that increase blood glucose levels. When the level of happiness increases the level of cortisol does not increase.
<h3>What are cortisol and its function?</h3>
Cortisol is the steroidal hormone that is produced in the cortex of the adrenal glands and is discharged in the blood vessels when in stress or danger.
It has a variety of functions including regulation of the blood pressure, response to the stressful condition and increase of the metabolism of the body.
It also acts as happiness hormones along with adrenaline and oxytocin but is a major flight or fight hormone and increases the heart rate in dangerous conditions.
Therefore, the statement is false.
Learn more about cortisol here:
brainly.com/question/26291522
