Answer:
smelling rotten eggs - covering your nose
touching a hot dish - pulling your hand away
jumping into a cold pool - shivering
Explanation:
<u>A stimulus generally refers to a detectable change in the environment of an organism. These changes could be physical or chemical and could be in the internal or external environment of organisms. </u>
Organisms react to changes in their internal or external environment by responding appropriately. Hence perceiving the smell of rotten egg, feeling the hotness of a dish by touching it, and feeling cold immediately one jumps into a cold pool are all examples of stimuli and their corresponding responses would be covering one's nose, pulling the hand away, and shivering of the body in order to counter the cold.
In other words:
<em>smelling rotten eggs - covering your nose</em>
<em>touching a hot dish - pulling your hand away</em>
<em>jumping into a cold pool - shivering</em>
The normal membrane potential inside the axon of nerve cells is –70mV, and since this potential can change in nerve cells it is called the resting potential. When a stimulus is applied a brief reversal of the membrane potential, lasting about a millisecond, occurs. This brief reversal is called the action potential
<span>A stimulus can cause the membrane potential to change a little. The voltage-gated ion channels can detect this change, and when the potential reaches –30mV the sodium channels open for 0.5ms. The causes sodium ions to rush in, making the inside of the cell more positive. This phase is referred to as a depolarisation since the normal voltage polarity (negative inside) is reversed (becomes positive inside). </span>
<span>Repolarisation. At a certain point, the depolarisation of the membrane causes the sodium channels to close. As a result the potassium channels open for 0.5ms, causing potassium ions to rush out, making the inside more negative again. Since this restores the original polarity, it is called repolarisation. As the polarity becomes restored, there is a slight ‘overshoot’ in the movement of potassium ions (called hyperpolarisation). The resting membrane potential is restored by the Na+K+ATPase pump.</span>
Answer:
Cellular respiration converts oxygen and glucose into water and carbon dioxide. Water and carbon dioxide are by- products and ATP is energy that is transformed from the process.
Answer:
The correct answer is "Histones in general have a net negative charge that allow them to bind to DNA. Acetylation of histones, decreases their positive charge and weakens the histone-DNA interaction".
Explanation:
Histone acetyltransferases (HATs) are regulators of gene activation and deactivation, achieved by the transference of an acetyl group from acetyl-CoA to histones. HATs function by the premise that histones in general have a net negative charge that allow them to bind to DNA. Acetylation of histones, decreases their positive charge and weakens the histone-DNA interaction. Therefore, most of the times histone acetylation increases gene expression, because the acetylated gene is free from the histones and is able to be encoded.
