Answer:
hypertonic then isotonic and hypotonic
Explanation:
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
Answer: Sexual reproduction is advantageous over asexual reproduction because it reduces the rate of mutation accumulation.
New Zealand mud snails reproduce through asexual and sexual modes of reproduction. Asexual reproduction allows these organisms to reproduce more number of offsprings. Asexual reproduction advantageous as these organisms faces natural disaster conditions like tide, drought results in the decrease in the population. Therefore, does not get mate to undergo sexual reproduction. Sexual reproduction in these snails results in genetic variation in offsprings. Sexual reproduction results in increase in mutation rate in the genetic material being passed to offsprings because of resorting of genetic material being distributed from parent to offspring. This will result in genetic variations. Hence, parent will be different from offsprings. In asexual reproduction offsprings are the clones of parents as there is no resorting of genetic material takes place.
It makes them float in water
