When Sarah performed this experiment, she changed the levels of nitrogen in order to observe the changes in the morphological features of the plant.
All of the characteristics of the plant that she observed were dependent on multiple different things, but the level of nitrogen was an independent variable that she was changing at her will.
Answer:
Answer is C.
Explanation:
For A and B, a base substitution affects one of the three bases that comprise a codon, the DNA/RNA unit that corresponds to a particular amino acid. If one base is substituted, one codon and therefore one amino acid will be affected. Codons have built-in redundancy, so even by changing one base, the new codon sometimes still corresponds to the same amino acid. Therefore, a base substitution at most affects one amino acid, and sometimes doesn't affect it all.
Frameshift mutations cause a lot more trouble. These occur when you have a deletion or insertion that changes the number of bases in your gene. As a result, the "frame" of the codons changes (everything shifts one way or the other by the number of bases added/removed). This affects EVERY codon downstream of the mutation, so you can imagine that such a mutation would have a bigger effect the closer to the start of the gene it occurs. This is why C is correct.
Answer:
5- action potential 6- receptors 7- calcium ions 8- sarcolemma
Explanation:
This description illustrates the pathway of a action potential traveling along a neuro-muscular junction. this functions as a chemical synapse between a motor neuron and a muscle fibre. It allow the motor neuron to transmit a signal/action potential to the muscle fiber, causing muscle contraction.
Answer:
The gray matter in the spinal cord is located in the <u><em>grey column</em></u> , and its shape resembles a letter H, or a butterfly. The cell bodies of somatic motor neurons are primarily housed in the <u><em>ventral or anterior</em></u> horns, which innervate skeletal muscle.
Explanation:
The grey matter is a component of the central nervous system that contains neuronal and glial cells and it can be found in the brain, brainstem and <em>spinal cord, in this last one, is found in the grey column, a mass of grey matter shaped in H form.</em>
In this column the grey matter is divided into four columns (as you can see in the image I added):
- The dorsal or posterior horn: contains somatosensorial neurons
- <em> The ventral or anterior horn: contains somatic efferent motor neurons (they exit the spinal cord to innervate skeletal muscle) </em>
- The intermediate column: contains neurons to innervate visceral organs
- The lateral horn: same as the intermediate column
I hope you find this information useful and interesting! Good luck!