Answer:
<u>acetylcholine</u>
Explanation:
In the pre-synaptic knob there are vesicles which contain a transmitter substance called acetylcholine. When an impulse reaches the synaptic knob, it stimulates the vesicles to move towards the pre-synaptic membrane releasing the acetylcholine.
The transmitter substance makes the membrane permeable. The neuromuscular junction contains the sensory neurone(afferent), motor neurones(efferent) and the relay neurones(connector).
It is false that cytoplasm is a single substance like water.
It consists of 80% water, but has other elements as well.
Fungi lacks the ability to produce their own food because they do not have chloroplast which is needed to obtain energy from the sun and convert it into food. Also fungi lack ability to fix nitrogen which has to be incorporated into their food. They also can not fix carbon and utilize it to produce food. Because of these they have to depend on dead organic matters for food.
the first answer as blood needs to be oxygenated to be passes round the body then when its deoxgenated it will return to the heart to be pumped around the body again
Mutations result either from errors in DNA replication or from the damaging effects of mutagens, such as chemicals and radiation, which react with DNA and change the structures of individual nucleotides. All cells possess DNA-repair enzymes that attempt to minimize the number of mutations that occur
