Answer:
1. The presynaptic neuron reaches the synaptic knob and the terminal is depolarized.
2. The electrical voltage gated calcium channels in the presynaptic knob opens.
3. The calcium ions enters through the calcium channel, this calcium ions cause the fusion of the synaptic vesicles to the presynaptic membrane, the cell membrane of an axon terminal that faces the receiving cell.
4. There is neurotransmitter release by the axon terminal of a neuron and bind to and react with the receptors on the dendrites of another neuron e.g. acetylcholine by exocytosis.
5. Acetylcholine diffuses across the synaptic cleft and bind to receptors on the postsynaptic neuron, that is a neuron to the cell body or dendrite of which an electrical impulse is transmitted across a synaptic cleft by the release of a chemical neurotransmitter from the axon terminal of a presynaptic neuron.
6. This causes sodium ion channels in the postsynaptic neuron to open, and sodium ions diffuse in.
7. Excitatory (excited neurons) postsynaptic potentials are created, and if these generator potentials are sufficient then the postsynaptic terminal reaches threshold potential and there is propagation.
Explanation: The nervous system is made up of billions of specialized cells called neurons, it is crucial to have an efficient communication between neurons for normal functioning of the central and peripheral nervous systems. The presynaptic action potential refers to an action potential of neuron before synapse. The above is the sequence of event during the transmission of information across the synaptic cleft
The correct answer is option A, that is, saturated.
The mentioned lipid is not a phospholipid, as it does not comprise a phosphate group at the terminal of the chain, and is not a triglyceride due to the absence of glycerol moiety.
Each carbon combined with the hydrogens forms the maximum number of possible C-H bonds, thus, there are no multiple bonds between the carbons. Hence, it can be concluded that the lipid is saturated.
Answer:
2%
Explanation:
The scientist believe that around 2% of the species that existed on Earth have been preserved in the fossil records. It is still a hot debate about it though, as there are only around 250,000 species identified in the fossil records so far, which is less than a quarter from the species that live in the present.
The reason why scientists believe that the majority of the species have not been preserved are very logical though. One of the reasons is that lot of species existed very long time ago, so their remains just didn't lasted so long. Other reason is the movement of the plates, where we have situation where plates that existed in the past have been totally suducted and melted in the mantle, while others are at the verge of it, so every fossil with them is melted and destroyed too. Another reason is that lot of species do not have hard parts, solid bone structure, so their preservation has been pretty much impossible,
Answer: They are easily identifiable.
Explanation:
There are wrinkled pods, smooth pods, white flowers and things like that that are easy to see right away.