1. Action potential reaches the axon terminal and depolarizes it.
2. Depolarization opens voltage-gated calcium channels, enabling influx of Ca into the neuron.
3. Calcium binds to specialized proteins on vesicles (containing pre-made acetylcholine) and triggers them to fuse with the neuron membrane at the synapse.
4. Exocytosis of acetylcholine into the synaptic cleft occurs.
5. Acetylcholine diffuses across the synapse and binds to nicotinic receptors on the end plate of the myocyte.
6. Activated nicotinic receptors, themselves ion channels, cause cation influx into the myocyte and generate an end plate potential. This eventually gives rise to the full depolarization within the myocyte that enables contraction.
Answer:
Steroid hormones that enter the cell activate receptors. These hormone-receptor complexes then bind HREs and influence gene expression.
Explanation:
Mechanism of action of steroid hormones is as follows:
- Steroid hormone enters cell and bind to the receptor.
- Translocation of activated receptor- ligand complex into nucleus.
- This complex then bind to another receptor on the chromatin.
- Steroid receptors form dimers.
- Act on DNA
- These hormone-receptor complexes then bind HREs and influence gene expression.
- Augmentation or Suppression of transcription.
Answer:
<em>The correct option is C) The success of a species depends on the number of offspring that survive long enough to reproduce.</em>
Explanation:
Some species of animals such as the octopus might give rise to many offspring, but these offspring might not survive due to different reasons. Only a few of them will be able to survive until the age where they can reproduce.
On the other hand, the survival rate of offspring which are formed in lesser numbers is more. These offspring are taken care of by their parents usually or are better adapted to live in the environment. Hence, their survival rate is more.
<span>I believe the answer would be B - the toy car would hit another toy car that would in turn hit another toy car, and so on. A wave has a ripple effect, so it will continue to happen down the line, until there is a force that stops it, or there are no more cars to hit.</span>
