Explanation:
Synapses are junctions at axon terminals where they connect to dendrites of other neurons at these junctions chemical reactions occur in order to facilitate the passage of information as chemical signals. There are several neuron types which include sensory motor and into neurons which bridge the two.
1. At neuromuscular junctions, electrical signals are transmitted:
- The action potential travels along the membrane until the synapse where it’s electrical depolarization leads to the opening of channels allowing only sodium ions to enter
- these flow through a presynaptic membrane until the concentration is built up, activating ion sensitive proteins attached to vesicles containing neurotransmitters like acetylcholine
- this leads to changes in the proteins leading to the fusion with the membrane of the presynaptic cell, so vesicles are open and neurotransmitter is released. The neurotransmitter diffuses across to chemical receptors on the presynaptic cell where they bind temporarily. This increases the permeability of the sarcolema to Na+;a new action potential is generated
2. Contraction of the sarcomere occurs via several steps.
- This action potential in the muscle, travels along T-tubules, and Ca+ ions are released by the sarcoplasmic reticulum into the sarcoplasm
- Ca and troponin combine, pulling myosin filaments, exposing the actin filament's myosin binding sites
- cross-bridge formation occurs, leading to the sliding of filaments.
- ATP drives cross-bridge cycling while mysosin pulls on actin strands
- muscle fibers shorten and contract
- later ACH is degraded in the synapse. Na ions are not released, and the action potential is not transmitted.
- the Ca channels on the SR close, while Ca is reabsorbed stopping Ca-troponin binding, closing myosin binding sites on actin and leading to cross bridge separation. The muscle fiber relaxes in their resting states.
Learn more about the autonomic nervous system at brainly.com/question/10386413
Learn more about neurotransmitters at brainly.com/question/9424160
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The identification of an individual by the means of genetic engineering is possible because the Y chromosomes in the males does not experience any crossing-over as there is only a single Y chromosome present in a human male.
The mitochondrial DNA is passed from the mother to child in the cytoplasm of the cell, and it is passed on without any changes. The X chromosome is can be passed from a mother to her son as he will receive Y chromosome from his father.
Hence, the correct answer is 'Option B - The Y chromosome does not experience crossing over'.
The proteins have 3 limbs one is brown one is purple and the other is green. Phenotypes are the are the contrasting color there for they make the organism work.
These include materials with the oldest DNA evidence of human<span> habitation in North America. The DNA, </span>radiocarbon<span> dated to 14,300 years ago, was found in fossilized </span>human coprolites<span> uncovered in the </span>Paisley Five Mile Point Caves<span> in south-central Oregon.
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R-organisms are usually bellow carrying capacity (<span>the maximum size of some population that can survive in the given environment)</span>. Those organisms are small and produce a great number of offspring. However, their life expectancy is short and many individuals die within a short time. Because of the high rate of death, they do not live long enough to reach their carrying capacity. Their life span is short, so even if predators were removed from the population, it would not be expected they will reach their carrying capacity.
