Answer:
Some substance in the infectious S strain could change the harmless R strain into the more lethal form.
Explanation:
These first type of experiments where crucial to advance in DNA knowledge.
In one experiment, they treated the material with enzymes that destroy all proteins. This is important because scientist notice that there was something else that was causing the strain to change into a lethal form and was heritable (DNA). Know a days we know that plasmids are responsible for such transformation.
Answer:
Generally, K+ ions ensures re-polarization of the membrane potential. It always ensures that the neuron returns its resting state, protecting the neurons and ensuring episode of rest before the next action potential.
K+ does this by leaving the axon, making the inner layer more negative. This is resting membrane potential. Because there are many K+ channels for leakages out of the neuronal axons.
Therefore, in this scenario, he neuron will return to its resting membrane potential state which between values -50 to -75mV.
Therefore the value of the potential will be -60mV, or within the range of -50 to -60mV. This is because the neuron is is non- excitable.
Explanation:
Answer:
Explanation:
DNA is deoxyribose nucleic acid. It is a double helical structure. It remains in the coiled form so as to make the information stored in the small region within the cell. The sequence of bases allows the information to be stored in the coded form so as to promote the synthesis of proteins. Complementary base pairing allows the DNA molecule to replicate itself.
Answer:
Having considered how an appropriate primary immune response is mounted to pathogens in both the peripheral lymphoid system and the mucosa-associated lymphoid tissues, we now turn to immunological memory, which is a feature of both compartments. Perhaps the most important consequence of an adaptive immune response is the establishment of a state of immunological memory. Immunological memory is the ability of the immune system to respond more rapidly and effectively to pathogens that have been encountered previously, and reflects the preexistence of a clonally expanded population of antigen-specific lymphocytes. Memory responses, which are called secondary, tertiary, and so on, depending on the number of exposures to antigen, also differ qualitatively from primary responses. This is particularly clear in the case of the antibody response, where the characteristics of antibodies produced in secondary and subsequent responses are distinct from those produced in the primary response to the same antigen. Memory T-cell responses have been harder to study, but can also be distinguished from the responses of naive or effector T cells. The principal focus of this section will be the altered character of memory responses, although we will also discuss emerging explanations of how immunological memory persists after exposure to antigen. A long-standing debate about whether specific memory is maintained by distinct populations of long-lived memory cells that can persist without residual antigen, or by lymphocytes that are under perpetual stimulation by residual antigen, appears to have been settled in favor of the former hypothesis.
Answer:
A. Population growth is decreasing
-2
+4
-10
-3
-8
-3
So the population decreased by 24 because 3+3+8+10+2=26-2=24.
