<span>The action of Helicase is to create replication forks and replication bubbles. Helicase is the first step in the DNA replication process. Helicase is an enzyme that breaks the hydrogen bond between the parental DNA to free the DNA double helix. The area where it unwinds is called as replication fork.</span>
Answer:
Option A, Start the reaction by absorbing light energy
Explanation:
Chlorophyll is a green color pigment in plant that helps in entrapping sunlight. Being green in color, it absorbs the blue and red light and reflects the green light. The molecules of chlorophyll gains energy from sunlight and then jumps to higher energy levels by the process known as photo excitation. These excited molecules get ionized to further initiate the process of photosynthesis.
Hence, option A is correct.
Answer:
The options:
What would be the next step in this experiment?
A. construct a hypothesis and record data
B. make observations and draw a conclusion
C. ask questions and construct a hypothesis
D. analyze the results and make a conclusion
The ANSWER should be D
D. analyze the results and make a conclusion
Explanation:
It should be D, the hypothesis has been proposed by her and she's left with conclusion on the experiment. From the type of exleriment, she has little observations to make since there's is a remote conclusion in a set time period.
The conduction of nerve impulses relies upon the movement of positively-charged ions across the nerve cell membrane. The entry of sodium into the cell produces a wave of positive charge that travels down the length of an axon. Then chemicals called neurotransmitters are secreted out of the end of the axon onto the next nerve in the series (the postsynpatic nerve). This narrow space in between neurons is called the synapse. These neurotransmiiters released by the presynaptic nerve bind to receptors on the postsynaptic nerve. The binding of these receptors opens up channels in this second nerve's membrane that allow sodium ions to enter the nerve cell and initiate another wave of positive charge, and so on... The nerve signal can only move as fast as these ions and neurotransmitters can diffuse to generate this process.
<span>As a professional athlete repeats a given activity many times over, the nerve cells "upregulate" their receptors, meaning that they produce additional receptors to put in the membrane. This is just a natural reaction to the nerve being repeatedly stimulated in the same way over and over. When neurotransmitter is secreted from the presynaptic neuron, there are more receptors on the postsynaptic neuron for it to bind, more channels open up, more ions enter in a shorter time and build up positive charge to create the impulse faster, and so the overall effect is faster. </span>
<span>Additionally, there are sheaths of fatty tissue (called myelin) that insulate the charge in the neuron and allow it to be conducted faster. As people age, these sheaths can start to degrade, making the nerve cell more "leaky" and causing the impulse to be conducted more slowly. </span>
